Constructing N-Containing Poly(p-Phenylene) (PPP) Films Through A Cathodic-Dehalogenation Polymerization Method

Developing the films of N-containing unsubstituted poly(p-phenylene) (PPP) films for diverse applications is significant and highly desirable because the replacement of sp2 C atoms with sp2 N atoms will bring novel properties to the as-prepared polymers. In this research, an electrochemical-dehalogenation polymerization strategy is employed to construct two N-containing PPP films under constant potentials, where 2,5-diiodopyridine (DIPy) and 2,5-dibromopyrazine (DBPz) are used as starting agents. The corresponding polymers are named CityU-23 (for polypyridine) and CityU-24 (for polypyrazine). Moreover, it is found that both polymers can form films in situ on different conductive substrates (i.e., silicon, gold, ITO, and nickel), satisfying potential device fabrication. Furthermore, the as-obtained thin films of CityU-23 and CityU-24 exhibit good performance of alkaline hydrogen evolution reaction with the overpotential of 212.8 and 180.7 mV and the Tafel slope of 157.0 and 122.4 mV dec-1, respectively.

Electro-Induced Phase Transformation of a Conductive Metal-Organic Framework Film for Nonlinear Optical Switching

Achieving metal-organic frameworks (MOFs) with nonlinear optical (NLO) switching is profoundly important. Herein, the conductive MOFs Cu-TCNQ phase I (Ph-I) and phase II (Ph-II) films were prepared using the liquid-phase-epitaxial layer-by-layer spin-coating method and steam heating method, respectively. Electronic experiments showed that the Ph-II film could be changed into the Ph-I film under an applied electric field. The third-order NLO results revealed that the Ph-I film had a third-order nonlinear reverse saturation absorption (RSA) response and the Ph-II film displayed a third-order nonlinear saturation absorption (SA) response. With increases in the heating time and applied voltage, the third-order NLO response realized the reversible transition between SA and RSA. The theoretical calculations indicated that Ph-I possessed more interlayer charge transfer, resulting in a third-order nonlinear RSA response that was stronger than that of Ph-II. This work applies phase-transformed MOFs to third-order NLO switching and provides new insights into the nonlinear photoelectric applications of MOFs.

Preparation and Properties of Low-Dielectric Polyimide Films Containing Tert-Butyl

The design of high-performance polyimide (PI) films and understanding the relationship of the structure-dielectric property are of great significance in the field of the microelectronics industry, but are challenging. Herein, we describe the first work to construct a series of novel tert-butyl PI films (denoted as PI-1, PI-2, PI-3, and PI-4) based on a low-temperature polymerization strategy, which employed tetracarboxylic dianhydride (pyromellitic anhydride, 3,3',4,4'-biphenyl tetracarboxylic anhydride, 4,4'-diphenyl ether dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic anhydride) and 4,4'-diamino-3,5-ditert butyl biphenyl ether as monomers. The results indicate that introducing tert-butyl branches in the main chain of PIs can enhance the free volume of the molecular chain and reduce the interaction between molecular chains of PI, resulting in a low dielectric constant. Particularly, the optimized PI-4 exhibits an excellent comprehensive performance with a high (5) wt% loss temperature (454 °C), tensile strength (117.40 MPa), and maximum hydrophobic angle (80.16°), and a low dielectric constant (2.90), which outperforms most of the results reported to date.

Chiral Metal-Organic Frameworks with Spectroscopic Methods: Towards Chemical Sensor Devices

Chiral Metal-Organic Frameworks (CMOFs) are a rapidly growing field reflecting their potential as selective and sensitive chemical sensors for chiral analytes. The highly tuneable nature of CMOFs enables the size, shape, and non-covalent interactions to be optimised towards specific analytes to engender strong intermolecular interactions and sensing responses. While CMOFs as chiral chemical sensor devices have been explored with electrochemical methods including differential pulse voltammetry (DPV), bipolar and chemiresistive sensing techniques, the CMOFs as chiral chemical sensors using spectroscopic methods has received significantly less attention. This review examines the synthesis of CMOFs for chemical sensors with spectroscopic methods such as photoluminescence, circular dichroism, and solid-state nuclear magnetic resonance with a view towards their incorporation into chemical sensor devices. Future directions of the field are highlighted for the generation of functional devices.

Is there scientific relevance to the plot of films and documentaries about eating disorders?

OBJECTIVES

to analyze films and documentaries about eating disorders from the last twenty years, identifying the way they approach the topic as well as their relevance for didactic use in teaching the health field.

METHODS

a descriptive study, whose data collection was carried out on the main streaming and video platforms, resulting in the survey of 60 media. Of these, only 25 had audio/subtitles in Portuguese (inclusion criteria). scientific relevance was analyzed considering psychopathological and epidemiological aspects of these disorders. A questionnaire about the plot, characters and descriptive data analysis were used.

RESULTS

most media were dramas about female teenagers who tried to conform to beauty stereotypes, whose symptoms portrayed converged with current medical diagnostic manuals.

CONCLUSIONS

in practical terms, a classificatory list of 11 media was prepared that could be used as a teaching resource for teaching this topic in the health field.

Silk Fibroin Materials: Biomedical Applications and Perspectives

The golden rule in tissue engineering is the creation of a synthetic device that simulates the native tissue, thus leading to the proper restoration of its anatomical and functional integrity, avoiding the limitations related to approaches based on autografts and allografts. The emergence of synthetic biocompatible materials has led to the production of innovative scaffolds that, if combined with cells and/or bioactive molecules, can improve tissue regeneration. In the last decade, silk fibroin (SF) has gained attention as a promising biomaterial in regenerative medicine due to its enhanced bio/cytocompatibility, chemical stability, and mechanical properties. Moreover, the possibility to produce advanced medical tools such as films, fibers, hydrogels, 3D porous scaffolds, non-woven scaffolds, particles or composite materials from a raw aqueous solution emphasizes the versatility of SF. Such devices are capable of meeting the most diverse tissue needs; hence, they represent an innovative clinical solution for the treatment of bone/cartilage, the cardiovascular system, neural, skin, and pancreatic tissue regeneration, as well as for many other biomedical applications. The present narrative review encompasses topics such as (i) the most interesting features of SF-based biomaterials, bare SF's biological nature and structural features, and comprehending the related chemo-physical properties and techniques used to produce the desired formulations of SF; (ii) the different applications of SF-based biomaterials and their related composite structures, discussing their biocompatibility and effectiveness in the medical field. Particularly, applications in regenerative medicine are also analyzed herein to highlight the different therapeutic strategies applied to various body sectors.

Sensitive Materials Used in Surface Acoustic Wave Gas Sensors for Detecting Sulfur-Containing Compounds

There have been many studies on surface acoustic wave (SAW) sensors for detecting sulfur-containing toxic or harmful gases. This paper aims to give an overview of the current state of polymer films used in SAW sensors for detecting deleterious gases. By covering most of the important polymer materials, the structures and types of polymers are summarized, and a variety of devices with different frequencies, such as delay lines and array sensors for detecting mustard gas, hydrogen sulfide, and sulfur dioxide, are introduced. The preparation method of polymer films, the sensitivity of the SAW gas sensor, the limit of detection, the influence of temperature and humidity, and the anti-interference ability are discussed in detail. The advantages and disadvantages of the films are analyzed, and the potential application of polymer films in the future is also forecasted.

Morphology and Mechanics of Star Copolymer Ultrathin Films Probed by Atomic Force Microscopy in the Air and in Liquid

Star copolymer films were produced by using spin-coating, drop-casting, and casting deposition techniques, thus obtaining ultrathin and thick films, respectively. The morphology is generally flat, but it becomes substrate-dependent for ultrathin films where the planarization effect of films is not efficient. The indentation hardness of films was investigated by Force Volume Maps in both the air and liquid. In the air, ultrathin films are in the substrate-dominated zone and, thus, the elastic modulus E is overestimated, while E reaches its bulk value for drop-casted ultrathin and thick films. In liquid (water), E follows an exponential decay for all films with a minimum soaked time t0 of 0.37 and 2.65 h for ultrathin and drop-casted ultrathin and thick films, respectively. After this time, E saturates to a value on average 92% smaller than that measured in the air due to film swelling. Such results support the role of film morphology in the antimicrobial activity envisaged in the literature, suggesting also an additional role of film hardness.

Assessment of chitosan-based adsorbents for glyphosate removal

Exposure to glyphosate produces various toxic effects, due to this, different methods have been evaluated for its elimination. The objective of this work was to formulate chitosan-based adsorbents and evaluate their efficiency in the removal of glyphosate in vitro. Four films were made by varying the weight ratio of silica/chitosan particles, and four sponges were made by varying the chitosan/chitosan ratio in a reticulated manner. Both adsorbents were characterized based on their porosity, water absorption, glyphosate removal, and reusability. It was found that increasing the porosity in both films and sponges resulted in an increase in the adsorption efficiency of glyphosate. The adsorption process exhibited a better fit in both adsorbents to the pseudo-second-order model. The adsorption of glyphosate to the films fit better with the Langmuir model, demonstrating that the process occurs in the form of a monolayer. In the case of sponges, the adsorption of glyphosate fit better with the Freundlich model, indicating that the process takes place in a multilayer form. Finally, when the reusability was evaluated, the adsorbents showed a loss of effectiveness. However, they still proved to be an efficient alternative for the removal of glyphosate in water, providing a cost-effective and environmentally friendly solution.

Support for policies restricting alcohol exposure in films: Does feeding back the amount of alcohol in films increase support?

INTRODUCTION

Alcohol exposure is common in popular films, and research has demonstrated a link between alcohol exposure and use. The likelihood of implementing specific policies to reduce the amount of film exposure is dependent on the level of public support; however, evidence is currently lacking. This study investigated how supportive people are of film-related alcohol policies and whether providing information about the amount of film exposure increased support.

METHODS

Australian adults (N = 252) first provided estimates of how much alcohol they thought were in popular films and then were randomised to either see an infographic about the amount of alcohol in films or not. All participants rated how supportive they were of eight policies.

RESULTS

The items 'alcoholic beverages and consumption should not be shown in G or PG rated films' (M = 3.54) and 'alcohol should not be glorified in films' (M = 3.49) were rated significantly higher than the scale's midpoint of 3 (p < 0.001). Participants who were older, female or reported lower alcohol use were more supportive of the policies. Only one policy item, 'information about alcohol sponsorship should be provided' received higher support from those who received the infographic compared to those who did not (M = 3.53 vs. M = 3.05; t(250) = -3.09, p = 0.002).

DISCUSSION AND CONCLUSION

Participants were relatively supportive of film alcohol policies. However, providing information about the amount of alcohol in films did not make a difference on the level of support for most film alcohol policies.

Effect of Materials Parameters on the Shape of Face-On Lamellae in Semi-Conducting Polymers: Insights From Qualitative Theory

Polymer semiconductors frequently form crystals or mesophases with lamellae, that comprise alternating layers of stacked backbones and side chains. Controlling lamellar orientation in films is essential for obtaining efficient charge carrier transport. Herein, lamellar orientation is investigated in an application-relevant setup: lamellae assembled on a substrate that strongly favors face-on orientation, but exposed to a film surface that promotes orientation along an "easy" direction, other than face on. It is assumed that the face-on order propagates from the substrate, but the lamellae bend to reduce their surface energy. A qualitative free-energy model is developed. The deformation is investigated as a function of film thickness, effective Young modulus, anchoring coefficient, and easy direction at the free surface. The calculations highlight the importance of elastic constants - lamellae can substantially deform already when Young moduli are only an order of magnitude smaller than the values that are reported for crystals. Softer Young moduli are expected when lamellar assembly occurs in a non-solidified mesophase that can be an equilibrium or (more speculatively) a transient state prior to crystallization. The alternative scenario of a two-layered film is also evaluated, where edge-on and face-on grains form, respectively, at the free surface and substrate.

Graphene-Enhanced Methacrylated Alginate Gel Films for Sustainable Dye Removal in Water Purification

Self-standing nanocomposite films were prepared by three-dimensional UV-induced radical copolymerization of methacrylated alginate (MALG) with acrylic acid (AA) and reinforced with graphene oxide (GO) to improve both mechanical strength and dye adsorption capacity in wastewater decontamination operations. Dynamic mechanical-thermal analysis revealed variations in storage modulus: the higher the GO content, the higher the storage modulus (E') values. Also, the higher the temperature (associated with a lower and lower water content of films), the larger values of E' for the films of the same composition (E'(25 °C) = 676.6-1538.7 MPa; E'(100 °C) = 886.9-2066.6 MPa), providing insights into the compatibility between GO and the MALG/AA matrix, as well as, assessing the improvement in the nanocomposite's final mechanical properties. These crosslinked films in a dry state exhibited rapid water uptake and relatively short drying times (ca. 30 min at room temperature for the MALG/AA/GO composites) resulting from the swelling-drying studies and water contact angle measurements. The efficacy of methylene blue removal from water assessed via UV-VIS spectrometry revealed excellent results, expressed as an adsorption yield of 70-80% and 85-98% after 30 h and 258 h, respectively, of immersion time of films into an MB aqueous solution of 12.5 mg/L (as the contaminated water model). The reusability of the same films was evaluated by consecutive extraction processes of MB from the composite membranes when the content of desorbed dye was also spectrophotometrically monitored and conducted in acidic conditions (HCl aqueous solutions of pH 2). Overall, the introduction of GO in the developed self-standing MALG/AA nanocomposite films exhibited enhanced mechanical properties and increased efficiency for dye removal applications. Their great reutilization potential was highlighted by low drying times and a good ability to release the dye initially adsorbed. Thus, the prepared films could be suitable materials for sustainable and effective water treatment technologies.

Antibacterial and Cytotoxic Study of Hybrid Films Based on Polypropylene and NiO or NiFe2O4 Nanoparticles

This study presents an in vitro analysis of the bactericidal and cytotoxic properties of hybrid films containing nickel oxide (NiO) and nickel ferrite (NiFe2O4) nanoparticles embedded in polypropylene (PP). The solvent casting method was used to synthesize films of PP, PP@NiO, and PP@NiFe2O4, which were characterized by different spectroscopic and microscopic techniques. The X-ray diffraction (XRD) patterns confirmed that the small crystallite sizes of NiO and NiFe2O4 NPs were maintained even after they were incorporated into the PP matrix. From the Raman scattering spectroscopy data, it was evident that there was a significant interaction between the NPs and the PP matrix. Additionally, the Scanning Electron Microscopy (SEM) analysis revealed a homogeneous dispersion of NiO and NiFe2O4 NPs throughout the PP matrix. The incorporation of the NPs was observed to alter the surface roughness of the films; this behavior was studied by atomic force microscopy (AFM). The antibacterial properties of all films were evaluated against Pseudomonas aeruginosa (ATCC®: 43636™) and Staphylococcus aureus (ATCC®: 23235™), two opportunistic and nosocomial pathogens. The PP@NiO and PP@ NiFe2O4 films showed over 90% bacterial growth inhibition for both strains. Additionally, the effects of the films on human skin cells, such as epidermal keratinocytes and dermal fibroblasts, were evaluated for cytotoxicity. The PP, PP@NiO, and PP@NiFe2O4 films were nontoxic to human keratinocytes. Furthermore, compared to the PP film, improved biocompatibility of the PP@NiFe2O4 film with human fibroblasts was observed. The methodology utilized in this study allows for the production of hybrid films that can inhibit the growth of Gram-positive bacteria, such as S. aureus, and Gram-negative bacteria, such as P. aeruginosa. These films have potential as coating materials to prevent bacterial proliferation on surfaces.

Current status and advances in esophageal drug delivery technology: influence of physiological, pathophysiological and pharmaceutical factors

Diseases affecting the esophagus are common. However, targeted drug delivery to the esophagus is challenging due to the anatomy and physiology of this organ. Current pharmacological treatment for esophageal diseases predominantly relies on the off-label use of drugs in various dosage forms, including those for systemic drug delivery (e.g. oral tablets, sublingual tablets, and injections) and topical drug delivery (e.g. metered dose inhaler, viscous solution or suspension, and endoscopic injection into the esophagus). In general, systemic therapy has shown the most efficacy but requires the use of high drug doses to achieve effective concentrations in the esophagus, which increases the risk of adverse effects and toxicity. Topical drug delivery has enormous potential in improving the way we treat patients with acute and chronic esophageal diseases, especially those requiring drugs that have low therapeutic index and/or significant adverse effects to non-targeted organs and tissues. This review will address the physiological, pathophysiological, and pharmaceutical considerations influencing topical drug delivery in the esophagus. The main conventional (e.g. liquid formulations, orodispersible tablets, lozenges, pastilles, troches, chewing gum) and innovative (e.g. stent-based, film-based, nanoparticulate-based) drug delivery approaches will be comprehensively discussed, along with the developments to improve their effectiveness for topical esophageal drug delivery. The translational challenges and future clinical advances of this research will also be discussed.

Effect of Substrates on the Physicochemical Properties of Li7La3Zr2O12 Films Obtained by Electrophoretic Deposition

Thin film technology of lithium-ion solid electrolytes should be developed for the creation of all-solid-state power sources. Solid electrolytes of the Li7La3Zr2O12 (LLZ) family are one of the promising membranes for all-solid-state batteries. LLZ films were obtained by electrophoretic deposition on Ti, Ni and steel substrates. The influence of different metal substrates on microstructure, phase composition and conductivity of the LLZ films after their heat treatment was studied. It was shown that the annealing of dried LLZ films in an Ar atmosphere leads to the transition from tetragonal modification to a low-temperature cubic structure. It was established that an impurity phase (Li2CO3) was not observed for LLZ films deposited on Ti foil after heat treatment, in contrast to films deposited on Ni and steel substrates. The highest lithium-ion conductivity values were achieved for the LLZ films annealed at 300 °C, 1.1 × 10-8 S cm-1 (at 100 °C) and 1.0 × 10-6 S cm-1 (at 200 °C).

Renewable and Functional Latexes Synthesized by Polymerization-Induced Self-Assembly for UV-Curable Films

After the development of polymer coatings and films based on renewable resources, there remains a challenge of combining the advantages of water-borne acrylic latexes with the excellent physical properties of cross-linked solvent-borne coatings. After polymerization, the renewable 4-oxocyclopentenyl acrylate (4CPA) is capable of undergoing photocyclodimerization under UV light, yielding a cross-linked polyacrylate. In this work, we investigate the polymerization-induced self-assembly (PISA) of 4CPA with several renewable acrylic monomers in the presence of a macro-RAFT agent. The produced latexes have a small particle size, good colloidal stability, and are free of volatile organic compounds. After film formation and UV curing, flexible to rigid films can be obtained depending on the monomer composition and UV irradiation time. The cross-linked films show promise as oil and water barriers in paper coating applications. This work outlines the development and application of renewable and functional cross-linkable latexes synthesized by PISA.

Can we still measure circular dichroism with circular dichroism spectrometers: The dangers of anisotropic artifacts

Chiral materials with strong linear anisotropies are difficult to accurately characterize with circular dichroism (CD) because of artifactual contributions to their spectra from linear dichroism (LD) and birefringence (LB). Historically, researchers have used a second-order Taylor series expansion on the Mueller matrix to model the LDLB interaction effects on the spectra in conventional materials, but this approach may no longer be sufficient to account for the artifactual CD signals in emergent materials. In this work, we present an expression to model the measured CD using a third-order expansion, which introduces "pairwise interference" terms that, unlike the LDLB terms, cannot be averaged out of the signal. We find that the third-order pairwise interference terms can make noticeable contributions to the simulated CD spectra. Using numerical simulations of the measured CD across a broad range of linear and chiral anisotropy parameters, the LDLB interactions are most prominent in samples that have strong linear anisotropies (LD, LB) but negligible chiral anisotropies, where the measured CD strays from the chirality-induced CD by factors greater than 103 . Additionally, the pairwise interactions are most significant in systems with moderate-to-strong chiral and linear anisotropies, where the measured CD is inflated twofold, a figure that grows as linear anisotropies approach their maximum. In summary, media with moderate-to-strong linear anisotropy are in great danger of having their CD altered by these effects in subtle manners. This work highlights the significance of considering distortions in CD measurements through higher-order pairwise interference effects in highly anisotropic nanomaterials.

TiB2-Derived Nanosheets Enhance the Tensile Strength and Controlled Drug Release of Biopolymeric Films Used in Wound Healing

Wound healing using an alginate-based biopolymeric film is one of the most preferred treatments. However, these films lack mechanical strength (elasticity and tensile strength), show higher initial burst release, and exhibit high vapor permeability. The present study reports the development of nanosheets derived from titanium diboride (10 nm) (NTB)-incorporated biopolymeric films (0.025, 0.05, and 0.1% w/v) using sodium alginate (SA) and carboxymethyl cellulose (CMC) to overcome the shortfalls. The surface properties of the film, nanosheet distribution within the film, and possible interactions with the film are explored by using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). These analyses confirm that nanosheets are uniformly distributed in the film and introduce unevenness on the film's surface. The tensile strength of the nanosheet-incorporated film (0.1% NTB film) using UTM is found to be 24.30 MPa (six times higher compared to the blank film), equivalent to human skin. The water vapor transmission rate of the film is also found to be in the desired range (i.e., 2000-2500 g/m2 day). The biocompatibility of the NTB film is confirmed by the MTT assay test using NIH/3T3 cells and HEK 293 cells. Furthermore, the scratch assay shows that the developed films promote cell migration and proliferation. The antibacterial activity of the film is also demonstrated using a model drug, tetracycline hydrochloride (TCl). Besides, the film exhibits the sustained release of TCl and follows the Korsmeyer-Peppas model for drug release. Overall, the 0.1% w/v NTB film is easy to fabricate, biocompatible and shows superior mechanical properties.

Tunable Light-Actuated Interpenetrating Networks of Silk Fibroin and Gelatin for Tissue Engineering and Flexible Biodevices

Soft materials with tunable properties are valuable for applications such as tissue engineering, electronic skins, and human-machine interfaces. Materials that are nature-derived offer additional advantages such as biocompatibility, biodegradability, low-cost sourcing, and sustainability. However, these materials often have contrasting properties that limit their use. For example, silk fibroin (SF) has high mechanical strength but lacks processability and cell-adhesive domains. Gelatin, derived from collagen, has excellent biological properties, but is fragile and lacks stability. To overcome these limitations, composites of gelatin and SF have been explored. However, mechanically robust self-supported matrices and electrochemically active or micropatterned substrates were not demonstrated. In this study, we present a composite of photopolymerizable SF and photogelatin, termed photofibrogel (PFG). By incorporating photoreactive properties in both SF and gelatin, control over material properties can be achieved. The PFG composite can be easily and rapidly formed into free-standing, high-resolution architectures with tunable properties. By optimizing the ratio of SF to gelatin, properties such as swelling, mechanical behavior, enzymatic degradation, and patternability are tailored. The PFG composite allows for macroscale and microscale patterning without significant swelling, enabling the fabrication of structures using photolithography and laser cutting techniques. PFG can be patterned with electrically conductive materials, making it suitable for cell guidance and stimulation. The versatility, mechanical robustness, bioactivity, and electrochemical properties of PFG are shown for skeletal muscle tissue engineering using C2C12 cells as a model. Overall, such composite biomaterials with tunable properties have broad potential in flexible bioelectronics, wound healing, regenerative medicine, and food systems.

Hierarchical self-assembly of a reflectin-derived peptide

Reflectins are a family of intrinsically disordered proteins involved in cephalopod camouflage, making them an interesting source for bioinspired optical materials. Understanding reflectin assembly into higher-order structures by standard biophysical methods enables the rational design of new materials, but it is difficult due to their low solubility. To address this challenge, we aim to understand the molecular self-assembly mechanism of reflectin's basic unit-the protopeptide sequence YMDMSGYQ-as a means to understand reflectin's assembly phenomena. Protopeptide self-assembly was triggered by different environmental cues, yielding supramolecular hydrogels, and characterized by experimental and theoretical methods. Protopeptide films were also prepared to assess optical properties. Our results support the hypothesis for the protopeptide aggregation model at an atomistic level, led by hydrophilic and hydrophobic interactions mediated by tyrosine residues. Protopeptide-derived films were optically active, presenting diffuse reflectance in the visible region of the light spectrum. Hence, these results contribute to a better understanding of the protopeptide structural assembly, crucial for the design of peptide- and reflectin-based functional materials.

Characterization and Applications of the Pectin Extracted from the Peel of Passiflora tripartita var. mollissima

The inadequate management of organic waste and excessive use of plastic containers cause damage to the environment; therefore, different studies have been carried out to obtain new biomaterials from agricultural subproducts. The objective of this work was to evaluate the feasibility of using the pectin extracted from the peel of Passiflora tripartita var. mollissima (PT), characterizing its type and viability for the production of edible biodegradable films. In addition, films of two thicknesses (23.45 ± 3.02 µm and 53.34 ± 2.28 µm) were prepared. The results indicated that PT is an excellent raw material for the extraction of pectin, with high yields (23.02 ± 0.02%), high galacturonic acid content (65.43 ± 2.241%), neutral sugars (ribose, xylose, glucose) and a high degree of esterification (76.93 ± 1.65%), classifying it as a high-methoxy pectin. Regarding the films, they were malleable and flexible, with a water vapor permeability from 2.57 × 10-10 ± 0.046 to 0.13 × 10-10 ± 0.029 g/s mPa according to thickness, being similar to other Passiflora varieties of edible films. The pectin extraction yield from PT makes this fruit a promising material for pectin production and its chemical composition a valuable additive for the food and pharmaceutical industries.

A Review of the Effect of Plasticizers on the Physical and Mechanical Properties of Alginate-Based Films

In recent years, there has been a growing attempt to manipulate various properties of biodegradable materials to use them as alternatives to their synthetic plastic counterparts. Alginate is a polysaccharide extracted from seaweed or soil bacteria that is considered one of the most promising materials for numerous applications. However, alginate potential for various applications is relatively limited due to brittleness, poor mechanical properties, scaling-up difficulties, and high water vapor permeability (WVP). Choosing an appropriate plasticizer can alleviate the situation by providing higher flexibility, workability, processability, and in some cases, higher hydrophobicity. This review paper discusses the main results and developments regarding the effects of various plasticizers on the properties of alginate-based films during the last decades. The plasticizers used for plasticizing alginate were classified into different categories, and their behavior under different concentrations and conditions was studied. Moreover, the drawback effects of plasticizers on the mechanical properties and WVP of the films are discussed. Finally, the role of plasticizers in the improved processing of alginate and the lack of knowledge on some aspects of plasticized alginate films is clarified, and accordingly, some recommendations for more classical studies of the plasticized alginate films in the future are offered.

Chitosan and Its Derivatives: Preparation and Antibacterial Properties

This comprehensive review illuminates the various methods of chitosan extraction, its antibacterial properties, and its multifarious applications in diverse sectors. We delve into chemical, physical, biological, hybrid, and green extraction techniques, each of which presents unique advantages and disadvantages. The choice of method is dictated by multiple variables, including the desired properties of chitosan, resource availability, cost, and environmental footprint. We explore the intricate relationship between chitosan's antibacterial activity and its properties, such as cationic density, molecular weight, water solubility, and pH. Furthermore, we spotlight the burgeoning applications of chitosan-based materials like films, nanoparticles, nonwoven materials, and hydrogels across the food, biomedical, and agricultural sectors. The review concludes by highlighting the promising future of chitosan, underpinned by technological advancements and growing sustainability consciousness. However, the critical challenges of optimizing chitosan's production for sustainability and efficiency remain to be tackled.

Thickness-Dependent Superconductivity in a Layered Electride on Silicon

Layered materials exhibit a plethora of fascinating properties. The challenge is to make the materials into epitaxial films, preferably integrated with mature technological platforms to facilitate their potential applications. Progress in this direction can establish the film thickness as a valuable parameter to control various phenomena, superconductivity in particular. Here, a synthetic route to epitaxial films of SrAlSi, a layered superconducting electride, on silicon is designed. A set of films ranging in thickness is synthesized employing a silicene-based template. Their structure and superconductivity are explored by a combination of techniques. Two regimes of TC dependence on the film thickness are identified, the coherence length being the crossover parameter. The results can be extended to syntheses of other honeycomb-lattice ternary compounds on Si or Ge exhibiting superconducting, magnetic, and other properties.

Portrayals of older adults in over 3000 films around the world

BACKGROUND

Presently, most film analyses related to older adults are peculiar to American cinema. However, film industries outside the United States are influential in their own right. As ageism is a pan-cultural phenomenon, it is important to explore filmic representations of older persons globally. This study is the first to offer a portrait of how filmic portrayals of older persons differ across regions.

METHODS

We leveraged a 200-million-word movie corpus comprising over 25,000 scripts from 88 countries in 11 regions. The movies span a period of nearly 90 years, from 1930 to 2018. We identified synonyms of "older adult(s)" and compiled the top descriptors that co-occurred most frequently with them. Seventeen thousand five hundred and eight descriptors were generated from 3384 movies. Using these descriptors, we calculated the valence of filmic portrayals of older adults on a scale of 1 (most negative) to 5 (most positive) in each region.

RESULTS

Positive representations of older adults in movies were lacking in all 11 regions. Four regions fell into the neutral zone and the remaining seven in the negative zone. Representations of older persons were the least negative in East Asia and South Asia, and most negative in Southeast Asia as well as the Middle East and North Africa (MENA). Our topic modeling revealed that older adults were portrayed as venerable in both South and East Asia. Meanwhile, older people were associated with death in MENA. The idea that society is ill-equipped to handle an aging population was hinted at in Southeast Asia.

CONCLUSIONS

As societies worldwide navigate a major demographic turning point, it is vital that filmmakers rethink portrayals of old age. In articulating the filmic narratives surrounding old age in different regions, our study lays the foundation to combat ageism on the big screen.

Liquid-Liquid Interfacial Nanoarchitectonics

Science in the small world has become a crucial key that has the potential to revolutionize materials technology. This trend is embodied in the postnanotechnology concept of nanoarchitectonics. The goal of nanoarchitectonics is to create bio-like functional structures, in which self-organized and hierarchical structures are working efficiently. Liquid-liquid interface like environments such as cell membrane surface are indispensable for the expression of biological functions through the accumulation and organization of functional materials. From this viewpoint, it is necessary to reconsider the liquid-liquid interface as a medium where nanoarchitectonics can play an active role. In this review, liquid-liquid interfacial nanoarchitectonics is classified by component materials such as organic, inorganic, carbon, and bio, and recent research examples are discussed. Examples discussed in this paper include molecular aggregates, supramolecular polymers, conductive polymers film, crystal-like capsules, block copolymer assemblies, covalent organic framework (COF) films, complex crystals, inorganic nanosheets, colloidosomes, fullerene assemblies, all-carbon π-conjugated graphite nanosheets, carbon nanoskins and fullerphene thin films at liquid-liquid interfaces. Furthermore, at the liquid-liquid interface using perfluorocarbons and aqueous phases, cell differentiation controls are discussed with the self-assembled structure of biomaterials. The significance of liquid-liquid interfacial nanoarchitectonics in the future development of materials will then be discussed.

Amino-Alcohol Organic-Inorganic Hybrid Sol-Gel Materials Based on an Epoxy Bicyclic Silane: Synthesis and Characterization

Organic-inorganic hybrids (OIHs) are a type of material that can be obtained using the sol-gel process and has the advantages of organic and inorganic moieties in a single material. Polyetheramines have been widely used in the preparation of this type of material, particularly in combination with epoxy-based alkoxysilanes. Nevertheless, epoxyciclohexylethyltrimethoxysilane (ECHETMS) is a promising alkoxysilane with an epoxy terminal group that is quite unexplored. In this work, four novel OIH materials were synthesized using the sol-gel method. The OIHs were based on Jeffamines® of different molecular weights (D-230, D-400, ED-600, and ED-900), together with ECHETMS. The materials were characterized using multinuclear solid state NMR, FTIR, BET, UV/Vis spectroscopy, EIS, and TGA. The influence of the Jeffamine molecular weight and the suitability of these materials to act as a supporting matrix for heteroaromatic probes were assessed and discussed. The materials show interesting properties in order to be applied in a wide range of sensing applications.

Development of Test Programs for the Biorelevant Characterization of Esophageal-Applied Dosage Forms

In the local treatment of the esophageal mucosa, the retention time of the different dosage forms, such as tablets, films or liquids, is of high relevance for the effective treatment of diseases. Unfortunately, there are only few in vitro models describing the esophageal route of administration. To predict the behaviour of an esophageal-applied dosage form, it is necessary to simulate the site of application in a biorelevant way. The aim of this work was to develop two test setups for an esophageal peristalsis model which was described in a previous study. Different parameters such as flow rate, peristalsis, angle of inclination or mucous membrane were varied or introduced into the model. A stimulated and unstimulated modus were developed and tested with two different dosage forms. The time until the dosage form was cleared from the in vitro model was shorter with the stimulated than with the unstimulated modus. Also, esophageal-applied films had a prolonged transit time compared to a viscous syrup. The modification of the simulated esophageal surface made it possible to estimate the retention time of the dosage forms. It could be demonstrated that the residence time of a dosage form depends on different parameters affecting each other.

The Structural and Electrochemical Properties of CuCoO2 Crystalline Nanopowders and Thin Films: Conductivity Experimental Analysis and Insights from Density Functional Theory Calculations

A novel manufacturing process is presented for producing nanopowders and thin films of CuCoO2 (CCO) material. This process utilizes three cost-effective synthesis methods: hydrothermal, sol-gel, and solid-state reactions. The resulting delafossite CuCoO2 samples were deposited onto transparent substrates through spray pyrolysis, forming innovative thin films with a nanocrystal powder structure. Prior to the transformation into thin films, CuCoO2 powder was first produced using a low-cost approach. The precursors for both powders and thin films were deposited onto glass surfaces using a spray pyrolysis process, and their characteristics were examined through X-ray diffraction, scanning electron microscopy, HR-TEM, UV-visible spectrophotometry, and electrochemical impedance spectroscopy (EIS) analyses were conducted to determine the conductivity in the transversal direction of this groundbreaking material for solar cell applications. On the other hand, the sheet resistance of the samples was investigated using the four-probe method to obtain the sheet resistivity and then calculate the in-plane conductivity of the samples. We also investigated the aging characteristics of different precursors with varying durations. The functional properties of CuCoO2 samples were explored by studying chelating agent and precursor solution aging periods using Density Functional Theory calculations (DFT). A complementary Density Functional Theory study was also performed in order to evaluate the electronic structure of this compound. Resuming, this study thoroughly discusses the synthesis of delafossite powders and their conversion into thin films, which hold potential as hole transport layers in transparent optoelectronic devices.

Xanthoceras sorbifolia Husk Extract Incorporation for the Improvement in Physical and Antioxidant Properties of Soy Protein Isolate Films

With the increasing awareness of ecological and environmental protection, the research on eco-friendly materials has experienced a considerable increase. The objective of our study was to explore a novel soy protein isolate (SPI) film functionalized with antioxidants extracted from Xanthoceras sorbifolia husk (XSHE) as bio-based active packaging films. The films were evaluated in light of their structure, physical machinery, and antioxidant performance using advanced characterization techniques. The FTIR and microscopy results revealed the hydrogen-bond interaction between the SPI and XSHE and their good compatibility, which contributed to the improvement in various properties of the composite films, such as tensile strength (TS), UV blocking, and the water barrier property. As the XSHE content increased to 5%, the TS of the films dramatically increased up to 7.37 MPa with 47.7% and the water vapor permeability decreased to 1.13 × 10-10 g m m-2 s-1 Pa-1 with 22.1%. Meanwhile, the introduction of XSHE caused further improvement in the antioxidant capacity of films, and the release of active agents from films was faster and higher in 10% ethanol than it was in a 50% ethanol food simulant. Overall, SPI-based films functionalized with XSHE demonstrated promising potential applications in food packaging.

Use of Chitosan from Southern King Crab to Develop Films Functionalized with RGD Peptides for Potential Tissue Engineering Applications

Southern King Crab (SKC) represents an important fishery resource that has the potential to be a natural source of chitosan (CS) production. In tissue engineering, CS is very useful to generate biomaterials. However, CS has a lack of signaling molecules that facilitate cell-substrate interaction. Therefore, RGD (arginine-glycine-aspartic acid) peptides corresponding to the main integrin recognition site in extracellular matrix proteins have been used to improve the CS surface. The aim of this study was to evaluate in vitro cell adhesion and proliferation of CS films synthesized from SKC shell wastes functionalized with RGD peptides. The FTIR spectrum of CS isolated from SKC shells (SKC-CS) was comparable to commercial CS. Thermal properties of films showed similar endothermic peaks at 53.4 and 53.0 °C in commercial CS and SKC-CS, respectively. The purification and molecular masses of the synthesized RGD peptides were confirmed using HPLC and ESI-MS mass spectrometry, respectively. Mouse embryonic fibroblast cells showed higher adhesion on SKC-CS (1% w/v) film when it was functionalized with linear RGD peptides. In contrast, a cyclic RGD peptide showed similar adhesion to control peptide (RDG), but the highest cell proliferation was after 48 h of culture. This study shows that functionalization of SKC-CS films with linear or cyclic RGD peptides are useful to improve effects on cell adhesion or cell proliferation. Furthermore, our work contributes to knowledge of a new source of CS to synthesize constructs for tissue engineering applications.

Films for Wound Healing Fabricated Using a Solvent Casting Technique

Wound healing is a complex process that involves restoring the structure of damaged tissues through four phases: hemostasis, inflammation, proliferation, and remodeling. Wound dressings are the most common treatment used to cover wounds, reduce infection risk and the loss of physiological fluids, and enhance wound healing. Despite there being several types of wound dressings based on different materials and fabricated through various techniques, polymeric films have been widely employed due to their biocompatibility and low immunogenicity. Furthermore, they are non-invasive, easy to apply, allow gas exchange, and can be transparent. Among different methods for designing polymeric films, solvent casting represents a reliable, preferable, and highly used technique due to its easygoing and relatively low-cost procedure compared to sophisticated methods such as spin coating, microfluidic spinning, or 3D printing. Therefore, this review focuses on the polymeric dressings obtained using this technique, emphasizing the critical manufacturing factors related to pharmaceuticals, specifically discussing the formulation variables necessary to create wound dressings that demonstrate effective performance.

Effects of the Solvent Vapor Exposure on the Optical Properties and Photocatalytic Behavior of Cellulose Acetate/Perylene Free-Standing Films

The search to deliver added value to industrialized biobased materials, such as cellulose derivatives, is a relevant aspect in the scientific, technological and innovation fields at present. To address these aspects, films of cellulose acetate (CA) and a perylene derivative (Pr) were fabricated using a solution-casting method with two different compositions. Consequently, these samples were exposed to dimethylformamide (DMF) solvent vapors so that its influence on the optical, wettability, and topographical properties of the films could be examined. The results demonstrated that solvent vapor could induce the apparent total or partial preferential orientation/migration of Pr toward the polymer-air interface. In addition, photocatalytic activities of the non-exposed and DMF vapor-exposed films against the degradation of methylene blue (MB) in an aqueous medium using light-emitting diode visible light irradiation were comparatively investigated. Apparently, the observed improvement in the performance of these materials in the MB photodegradation process is closely linked to the treatment with solvent vapor. Results from this study have allowed us to propose the fabrication and use of the improved photoactivity "all-organic" materials for potential applications in dye photodegradation in aqueous media.

Tensile and Surface Wettability Properties of the Solvent Cast Cellulose Fatty Acid Ester Films

Thermoplastic cellulose esters are promising materials for bioplastic packaging. For that usage, it is important to understand their mechanical and surface wettability properties. In this study, a series of cellulose esters are prepared, such as laurate, myristate, palmitate, and stearate. The aim of the study is to investigate the tensile and surface wettability properties of the synthesized cellulose fatty acid esters to understand their suitability as a bioplastic packaging material. Cellulose fatty acid esters are first synthesized from microcrystalline cellulose (MCC), then dissolved in pyridine solution, and after the solvent cast into thin films. The cellulose fatty acid ester acylation process is characterized by the FTIR method. Cellulose esters hydrophobicity is evaluated with contact angle measurements. The mechanical properties of the films are tested with the tensile test. For all the synthesized films, FTIR provides clear evidence of acylation by showing the presence of characteristic peaks. Films' mechanical properties are comparable to those of generally used plastics such as LDPE and HDPE. Furthermore, it appears that with an increase in the side-chain length, the water barrier properties showed improvement. These results show that they could potentially be suitable materials for films and packaging materials.

Laponite Composites: In Situ Films Forming as a Possible Healing Agent

A healing material must have desirable characteristics such as maintaining a physiological environment, protective barrier-forming abilities, exudate absorption, easy handling, and non-toxicity. Laponite is a synthetic clay with properties such as swelling, physical crosslinking, rheological stability, and drug entrapment, making it an interesting alternative for developing new dressings. This study evaluated its performance in lecithin/gelatin composites (LGL) as well as with the addition of maltodextrin/sodium ascorbate mixture (LGL MAS). These materials were applied as nanoparticles, dispersed, and prepared by using the gelatin desolvation method-eventually being turned into films via the solvent-casting method. Both types of composites were also studied as dispersions and films. Dynamic Light Scattering (DLS) and rheological techniques were used to characterize the dispersions, while the films' mechanical properties and drug release were determined. Laponite in an amount of 8.8 mg developed the optimal composites, reducing the particulate size and avoiding the agglomeration by its physical crosslinker and amphoteric properties. On the films, it enhanced the swelling and provided stability below 50 °C. Moreover, the study of drug release in maltodextrin and sodium ascorbate from LGL MAS was fitted to first-order and Korsmeyer-Peppas models, respectively. The aforementioned systems represent an interesting, innovative, and promising alternative in the field of healing materials.

Production and Characterization of k-Carrageenan Films Incorporating Cymbopogon winterianus Essential Oil as New Food Packaging Materials

The global production of synthetic plastics from petroleum-based raw ingredients exceeds 150 million metric tons. The environment is threatened by tons of plastic waste, thus endangering wildlife and the public's health. These consequences increased the interest in biodegradable polymers as potential substitutes for traditional packaging materials. This study aimed to produce and characterize k-carrageenan films incorporating Cymbopogon winterianus essential oil, in which citronellal was determined to be the major compound (41.12%). This essential oil presented remarkable antioxidant activity, as measured through DPPH (IC₅₀ = 0.06 ± 0.01%, v/v; AAI = 85.60 ± 13.42) and β-carotene bleaching (IC₅₀ = 3.16 ± 0.48%, v/v) methods. The essential oil also showed antibacterial properties against Listeria monocytogenes LMG 16779 (diameter of inhibition zone = 31.67 ± 5.16 mm and MIC = 8 µL/mL), which were also observed when incorporated in the k-carrageenan films. Moreover, scanning electron microscopy showed the reduction of the biofilms of this bacterium, and even its inactivation, due to visible destruction and loss of integrity when the biofilms were created directly on the developed k-carrageenan films. This study also revealed the quorum sensing inhibition potential of Cymbopogon winterianus essential oil (diameter of violacein production inhibition = 10.93 ± 0.81 mm), where it could impede intercellular communication and, hence, lower violacein synthesis. The produced k-carrageenan films were transparent (>90%) and slightly hydrophobic (water contact angle > 90°). This work demonstrated the viability of using Cymbopogon winterianus essential oil to produce k-carrageenan bioactive films as new food packaging materials. Future work should focus on the scale-up production of these films.

Halide Perovskites Films for Ionizing Radiation Detection: An Overview of Novel Solid-State Devices

Halide perovskites are a novel class of semiconductors that have attracted great interest in recent decades due to their peculiar properties of interest for optoelectronics. In fact, their use ranges from the field of sensors and light emitters to ionizing radiation detectors. Since 2015, ionizing radiation detectors exploiting perovskite films as active media have been developed. Recently, it has also been demonstrated that such devices can be suitable for medical and diagnostic applications. This review collects most of the recent and innovative publications regarding solid-state devices for the detection of X-rays, neutrons, and protons based on perovskite thin and thick films in order to show that this type of material can be used to design a new generation of devices and sensors. Thin and thick films of halide perovskites are indeed excellent candidates for low-cost and large-area device applications, where the film morphology allows the implementation on flexible devices, which is a cutting-edge topic in the sensor sector.

Changes in tobacco imagery and smokers' depiction in Spanish top-grossing films before and after the implementation of a comprehensive tobacco control policy in Spain

INTRODUCTION

As more restrictions on tobacco marketing communication are implemented, tobacco marketing has persisted through smoking in films. Our aims were to assess changes in tobacco imagery exposure in Spanish top-grossing films before and after the banning of tobacco advertising in Spain, and to determine whether the depiction of smoking characters has changed over the years.

METHODS

A repeated cross-sectional study measured the tobacco content in the 10 Spanish top-grossing films in 2005, 2010 and 2015 (n=30) before and after a complete tobacco advertising ban. We conducted a descriptive and regression analysis of changes in tobacco impressions by year.

RESULTS

The 30 films contained 1378 tobacco occurrences (90.2% positive for tobacco) with a median length of eight seconds onscreen. Total tobacco occurrences deemed positive for tobacco interests significantly increased in 2010 and 2015 compared to 2005. However, we observed decreased odds of tobacco brands appearances (OR=0.25; p<0.001) in 2010 and of implied tobacco use (OR=0.44; p=0.002), and tobacco brands appearances (OR=0.36; p<0.001) in 2015 compared to 2005. There was a change of pattern in the type of role smokers played from a leading role to a supporting one (p<0.001). The population reach of positive for tobacco occurrence in Spanish top-grossing films decreased from 15.9 (95% CI: 15.86-15.86) per 1000 spectators in 2005 to 0.8 (95% CI: 0.82-0.82) in 2015.

CONCLUSIONS

The implementation of a ban on complete tobacco product advertising was followed by a decrease in tobacco incidents across top-grossing Spanish films. Yet, exposure to smoking in films is still unacceptably high.

Modification of Macromolecules of Polyimide Films by Electron Irradiation

New polymeric materials formation by controlling their properties is the primary and most challenging problem in developing a methodology for synthesizing a chosen technology and its use. The combined effect of high-energy electron radiation and tensile stress will cause a decrease in crystallinity and the breakage of chemical bonds in polyimide film macromolecules and is a new approach in their production technology. The effect of uniaxial tension and electron irradiation on the modification of polyimide film at room temperature was studied. Irradiation of the films caused an increase in the intensity of the IR spectrum by ~2-6 times and an increase in the width of the bands. The intensity in the range of 1700-3500 cm^-1 increased, indicating an increase in the content of radicals as a result of irradiation. The amplitudes of the electron paramagnetic resonance signal from non-irradiated films increased from 3 × 10³ to 5 × 10³ as a result of uniaxial tension to fracture, indicating an increase in radicals in the material. The lines of the electron paramagnetic resonance spectrum shifted from 3475.0 cm^-1 to 3512.5 cm^-1, with a simultaneous decrease in the signal's amplitude from 6 ×10³ to 4 × 10³, as a result of the electron irradiation of the films, followed by their subjection to tension. This was due to a decrease in the concentration of the radicals of the =N-H and -N-H₂ groups until their disappearance and the formation of new ones.

LDH-Based "Smart" Films for Corrosion Sensing and Protection

In a "smart" corrosion-protective coating system, both the active anti-corrosion and the early corrosion detection of underlying metals are highly required. It is practical significant to develop materials that possess self-detecting of the early local corrosion and self-healing of coating defects simultaneously. The organic compound 8-hydroxyquinoline (8HQ) is an effective inhibitor and a fluorescent sensor probe for corrosion of aluminum alloy. Therefore, a layer double hydroxide (LDH) nanocontainer film loaded with the 8HQ was developed for the active corrosion protection purpose of aluminum alloy AA2024. In corrosive environments, the 8HQ are released from LDH film to inhibit the corrosion process, leading to the loss of the complexation with Al³⁺ ions in LDH laminates, thus turning off fluorescence. Results show that the LDH film loaded with 8HQ composites can improve the anti-corrosion performance of the film by releasing corrosion inhibitors on demand. Simultaneously, due to the complexation of 8HQ and Al³⁺ ions, the LDH film is fluorescent at the initial stage under ultraviolet light, and then becomes non-fluorescent at the corrosion sites, indicating the corrosion evolution process of the coating. The 8HQ-loaded LDH film with self-healing and self-detecting dual functions provides promising opportunities for the effective corrosion protection of aluminum alloy due to its "smart" and multifunctional properties.

Using Different Surface Energy Models to Assess the Interactions between Antiviral Coating Films and phi6 Model Virus

High molecular weight chitosan (HMWCh), quaternised cellulose nanofibrils (qCNF), and their mixture showed antiviral potential in liquid phase, while this effect decreased when applied to facial masks, as studied in our recent work. To gain more insight into material antiviral activity, spin-coated thin films were prepared from each suspension (HMWCh, qCNF) and their mixture with a 1:1 ratio. To understand their mechanism of action, the interactions between these model films with various polar and nonpolar liquids and bacteriophage phi6 (in liquid phase) as a viral surrogate were studied. Surface free energy (SFE) estimates were used as a tool to evaluate the potential adhesion of different polar liquid phases to these films by contact angle measurements (CA) using the sessile drop method. The Fowkes, Owens-Wendt-Rabel-Kealble (OWRK), Wu, and van Oss-Chaudhury-Good (vOGC) mathematical models were used to estimate surface free energy and its polar and dispersive contributions, as well as the Lewis acid and Lewis base contributions. In addition, the surface tension SFT of liquids was also determined. The adhesion and cohesion forces in wetting processes were also observed. The estimated SFE of spin-coated films varied between mathematical models (26-31 mJ/m²) depending on the polarity of the solvents tested, but the correlation between models clearly indicated a significant dominance of the dispersion components that hinder wettability. The poor wettability was also supported by the fact that the cohesive forces in the liquid phase were stronger than the adhesion to the contact surface. In addition, the dispersive (hydrophobic) component dominated in the phi6 dispersion, and since this was also the case in the spin-coated films, it can be assumed that weak physical van der Waals forces (dispersion forces) and hydrophobic interactions occurred between phi6 and the polysaccharide films, resulting in the virus not being in sufficient contact with the tested material during antiviral testing of the material to be inactivated by the active coatings of the polysaccharides used. Regarding the contact killing mechanism, this is a disadvantage that can be overcome by changing the previous material surface (activation). In this way, HMWCh, qCNF, and their mixture can attach to the material surface with better adhesion, thickness, and different shape and orientation, resulting in a more dominant polar fraction of SFE and thus enabling the interactions within the polar part of phi6 dispersion.

Biological potential of polysaccharides extracted from Nostoc colonies for film production - Physical and biological properties

Cyanobacteria of the Nostoc genus secrete a number of biologically active compounds, including polysaccharides, which may exhibit antioxidant, antimicrobial, anticancer, and anti-inflammatory properties. The aim of the study was to investigate the biological properties of Nostoc polysaccharides (NPs) (antioxidative and antimicrobial) and the possibility of using NPs addition in the production of biofoils. Our results allow to indicate that NPs were compatible with the used biopolymer matrix (furcellaran and chitosan) and showed antioxidant properties. The tested polysaccharide extracts (0.14%) exhibited the ability to neutralize free radicals - 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) at a level of 4.46% and 10.14%, respectively. NP extracts demonstrated reducing properties of 15.35 and 30.07 mg Trolox equivalents (FRAP and CUPRAC methods, respectively) and 2.64 mg chlorogenic acid equivalents (tested with Folin's reagent). NP extracts showed: a growth-stimulating effect (Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae), no effect (Penicillum sp.), or a slight inhibitory effect (Streptomyces sp.) on the tested microorganisms. The enrichment of the film with NPs influenced the physic-chemical properties of the obtained biofoils. The addition of polysaccharides to furcellaran and chitosan films decreased their water solubility (by approximately 40% and 9%, respectively, compared to the control) and, at the same time increased, their water absorption.

Preparation and In Vitro Evaluation of Chitosan-g-Oligolactide Based Films and Macroporous Hydrogels for Tissue Engineering

In the current study, novel matrices based on chitosan-g-oligo (L,L-/L,D-lactide) copolymers were fabricated. In particular, 2D films were prepared by solvent casting, while 3D macroporous hydrogels were obtained by lyophilization of copolymer solutions. Copolymers of chitosan (Chit) with semi-crystalline oligo (L,L-lactide) (Chit-LL) or amorphous oligo (L,D-lactide) (Chit-LD) were obtained by solid-state mechanochemical synthesis. The structure of the hydrogels was found to be a system of interconnected macropores with an average size of 150 μm. In vitro degradation of these copolymer-based matrices was shown to increase in the case of the Chit-LL-based hydrogel by 34% and decrease for the Chit-LD-based hydrogel by 23% compared to the parameter of the Chit sample. Localization and distribution of mouse fibroblast L929 cells and adipose tissue-derived mesenchymal stromal cells (MSCs) within the hydrogels was studied by confocal laser scanning microscopy (CLSM). Moreover, cellular response, namely cell adhesion, spreading, growth, proliferation, as well as cell differentiation in vitro were also evaluated in the hydrogels for 10-14 days. Both the Chit-LL and Chit-LD matrices were shown to support cell growth and proliferation, while they had improved swelling compared to the Chit matrix. Osteogenic MSCs differentiation on the copolymer-based films was studied by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Maximal expression levels of osteogenesis markers (alkaline phosphatase (ALPL), bone transcription factor (Runx2), and osteopontin (SPP1) were revealed for the Chit-LD films. Thus, osteodifferentiation was demonstrated to depend on the film composition. Both Chit-LL and Chit-LD copolymer-based matrices are promising for tissue engineering.

The Piezoresponse in WO3 Thin Films Due to N2-Filled Nanovoids Enrichment by Atom Probe Tomography

Tungsten trioxide (WO₃) is a versatile n-type semiconductor with outstanding chromogenic properties highly used to fabricate sensors and electrochromic devices. We present a comprehensive experimental study related to piezoresponse with piezoelectric coefficient d₃₃ = 35 pmV^-1 on WO₃ thin films ~200 nm deposited using RF-sputtering onto alumina (Al₂O₃) substrate with post-deposit annealing treatment of 400 °C in a 3% H₂/N₂-forming gas environment. X-ray diffraction (XRD) confirms a mixture of orthorhombic and tetragonal phases of WO₃ with domains with different polarization orientations and hysteresis behavior as observed by piezoresponse force microscopy (PFM). Furthermore, using atom probe tomography (APT), the microstructure reveals the formation of N₂-filled nanovoids that acts as strain centers producing a local deformation of the WO₃ lattice into a non-centrosymmetric structure, which is related to piezoresponse observations.

Influence of PHA Substrate Surface Characteristics on the Functional State of Endothelial Cells

The needs of modern regenerative medicine for biodegradable polymers are wide and varied. Restoration of the viability of the vascular tree is one of the most important components of the preservation of the usefulness of organs and tissues. The creation of vascular implants compatible with blood is an important task of vascular bioengineering. The function of the endothelial layer of the vessel, being largely responsible for the development of thrombotic complications, is of great importance for hemocompatibility. The development of surfaces with specific characteristics of biomaterials that are used in vascular technologies is one of the solutions for their correct endothelialization. Linear polyhydroxyalkanoates (PHAs) are biodegradable structural polymeric materials suitable for obtaining various types of implants and tissue engineering, having a wide range of structural and physicomechanical properties. The use of PHA of various monomeric compositions in endothelial cultivation makes it possible to evaluate the influence of material properties, especially surface characteristics, on the functional state of cells. It has been established that PHA samples with the inclusion of 3-hydroxyhexanoate have optimal characteristics for the formation of a human umbilical vein endothelial cell, HUVEC, monolayer in terms of cell morphology as well as the levels of expression of vinculin and VE-cadherin. The obtained results provide a rationale for the use of PHA copolymers as materials for direct contact with the endothelium in vascular implants.

Structural, Mechanical, and Tribological Properties of Oriented Ultra-High Molecular Weight Polyethylene/Graphene Nanoplates/Polyaniline Films

Preparing high-strength polymeric materials using an orientation drawing process is considered one of the most urgent topics in the modern world. Graphene nanoplates/polyaniline (GNP/PANI) were added to the commercial grade UHMWPE (GUR 4120) matrix as a filler with antifriction properties. The effect of GNP/PANI addition on the structure, the orientation process, the void formation (cavitation), the mechanical, and tribological properties was studied using differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA), and scanning electron microscopy (SEM). The paper's findings indicated an increase in the cavitation effect of 120-320% after the addition of GNP/PANI to the UHMWPE polymer matrix. This increase, during the process of the oriented films' thermal orientation hardening, led, in turn, to a decrease in the tensile strength during the process of the oriented films' thermal orientation hardening. Furthermore, the decrease in the coefficient of friction in the best samples of oriented UHMWPE films was two times greater, and the increase in wear resistance was more than an order of magnitude. This process was part of the orientation hardening process for the UHMWPE films containing PE-wax as an intermolecular lubricant, as well as the presence of GNP/PANI in the material, which have a high resistance to abrasive wear.

Chitosan-Based Green Pea (Pisum sativum L.) Pod Extract Gel Film: Characterization and Application in Food Packaging

This work focuses on studying the preparation, characterization (physical, mechanical, optical, and morphological properties as well as antioxidant and antimicrobial activities) and packaging application of chitosan (CH)-based gel films containing varying empty green pea pod extract (EPPE) concentrations (0, 1, 3, and 5% w/w). The experiments revealed that adding EPPE to CH increased the thickness (from 0.132 ± 0.08 to 0.216 ± 0.08 mm), density (from 1.13 ± 0.02 to 1.94 ± 0.02 g/cm³), and opacity (from 0.71 ± 0.02 to 1.23 ± 0.04), while decreasing the water vapour permeability, water solubility, oil absorption ratio, and whiteness index from 2.34 to 1.08 × 10^-10 g^-1 s^-1 pa^-1, from 29.40 ± 1.23 to 18.75 ± 1.94%, from 0.31 ± 0.006 to 0.08 ± 0.001%, and from 88.10 ± 0.43 to 77.53 ± 0.48, respectively. The EPPE films had better tensile strength (maximum of 26.87 ± 1.38 MPa), elongation percentage (maximum of 58.64 ± 3.00%), biodegradability (maximum of 48.61% after 3 weeks), and migration percentages than the pure CH-gel film. With the addition of EPPE, the antioxidant and antibacterial activity of the film improved. SEM revealed that as EPPE concentration increased, agglomerates formed within the films. Moreover, compared to control samples, packing corn oil in CH-based EPPE gel films slowed the rise of thiobarbituric acid and peroxide values. As an industrial application, CH-based EPPE films have the potential to be beneficial in food packaging.

Cellulose-Chitosan Functional Biocomposites

Here, we present a detailed review of recent research and achievements in the field of combining two extremely important polysaccharides; namely, cellulose and chitosan. The most important properties of the two polysaccharides are outlined, giving rise to the interest in their combination. We present various structures and forms of composite materials that have been developed recently. Thus, aerogels, hydrogels, films, foams, membranes, fibres, and nanofibres are discussed, alongside the main techniques for their fabrication, such as coextrusion, co-casting, electrospinning, coating, and adsorption. It is shown that the combination of bacterial cellulose with chitosan has recently gained increasing attention. This is particularly attractive, because both are representative of a biopolymer that is biodegradable and friendly to humans and the environment. The rising standard of living and growing environmental awareness are the driving forces for the development of these materials. In this review, we have shown that the field of combining these two extraordinary polysaccharides is an inexhaustible source of ideas and opportunities for the development of advanced functional materials.

Duplex Coating Combing Vanadate-Intercalated Layered Double Hydroxide and Ce-Doped Sol-Gel Layers on Aluminum Alloy for Active Corrosion Protection

In this study, a duplex coating system (LDH-V/SG-Ce) of vanadate-intercalated layered double hydroxide (LDH) and Ce-doped sol-gel (SG) layers was developed for the purpose of active corrosion protection of the aluminum alloy AA2024. ZnAl-LDH film was grown in situ on the surface of an aluminum alloy using a hydrothermal method and intercalated with V₂O₇^4- anions as corrosion inhibitors, and sealed with a Ce (III)-doped silane coating using a sol-gel technique. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses were used to analyze the microstructure, surface functional groups and structure of the LDH-V/SG-Ce film. The uniform and compact silane layer was covered both in the pores and on top of the LDH film. The results of glow discharge optical emission spectroscopy (GDOES) indicated that V₂O₇^4- and Ce (III) ions were loaded in the LDH layer and silane film, respectively. The potentiodynamic polarization results showed that the corrosion current density of the bilayer system in the presence of corrosion inhibitors was reduced to 1.92 × 10^-8 A/cm². Electrochemical impedance spectroscopy (EIS) results showed that the LDH-V/SG-Ce duplex coating could provide effective protection for the aluminum alloy after being exposed to a corrosive solution for 14 days.

Anthracnose Controlled by Essential Oils: Are Nanoemulsion-Based Films and Coatings a Viable and Efficient Technology for Tropical Fruit Preservation?

Post-harvest diseases can be a huge problem for the tropical fruit sector. These fruits are generally consumed in natura; thus, their integrity and appearance directly affect commercialization and consumer desire. Anthracnose is caused by fungi of the genus Colletotrichum and affects tropical fruits, resulting in lesions that impair their appearance and consumption. Antifungals generally used to treat anthracnose can be harmful to human health, as well as to the environment. Therefore, essential oils (EO) have been investigated as natural biofungicides, successfully controlling anthracnose symptoms. The hydrophobicity, high volatility, and oxidative instability of essential oils limit their direct application; hence, these oils must be stabilized before food application. Distinct delivery systems have already been proposed to protect/stabilize EOs, and nanotechnology has recently reshaped the food application limits of EOs. This review presents robust data regarding nanotechnology application and EO antifungal properties, providing new perspectives to further improve the results already achieved in the treatment of anthracnose. Additionally, it evaluates the current scenario involving the application of EO directly or incorporated in films and coatings for anthracnose treatment in tropical fruits, which is of great importance, especially for those fruits intended for exportation that may have a prolonged shelf life.