Ammonia-sensitive cellulose acetate-based films incorporated with Co-BIT microcrystals for smart packaging application

Nowadays, there is an increasing demand for smart packaging materials capable of effectively monitoring the food freshness. In this study, new Co-based MOF (Co-BIT) microcrystals with ammonia-sensitivity and antibacterial function were constructed and then loaded within cellulose acetate (CA) matrix to create smart active packaging materials. The influences of Co-BIT loading upon structure, physical, and functional properties of the CA films were then thoroughly explored. It was observed that microcrystalline Co-BIT was uniformly integrated inside CA matrix, which caused significant promotions in mechanical strength (from 24.12 to 39.76 MPa), water barrier (from 9.32 × 10^-6 to 2.73 × 10^-6 g/m·h·Pa) and ultraviolet light protection performances of CA film. Additionally, the created CA/Co-BIT films displayed striking antibacterial efficacy (>95.0 % for both Escherichia coli and Staphylococcus aureus), favorable ammonia-sensitivity function as well as color stability. Finally, the CA/Co-BIT films were successfully applied for indicating the spoilage of shrimp through discernible color changes. These findings suggest that Co-BIT loaded CA composite films have great potential for use as smart active packaging.

Effect of degree of substitution on the microphase separation and mechanical properties of cellooligosaccharide acetate-based elastomers

Thermoplastic elastomers (TPEs) have long been used in a wide range of industries. However, most existing TPEs are petroleum-derived polymers. To realize environmentally benign alternatives to conventional TPEs, cellulose acetate is a promising TPE hard segment because of its sufficient mechanical properties, availability from renewable sources, and biodegradability in natural environments. Because the degree of substitution (DS) of cellulose acetate governs a range of physical properties, it is a useful parameter for designing novel cellulose acetate-based TPEs. In this study, we synthesized cellulose acetate-based ABA-type triblock copolymers (AcCel_x-b-PDL-b-AcCel_x) containing a celloologosaccharide acetate hard A segment (AcCel_x, where x is the DS; x = 3.0, 2.6, and 2.3) and a poly(δ-decanolactone) (PDL) soft B segment. Small-angle X-ray scattering showed that decreasing the DS of AcCel_x-b-PDL-b-AcCel_x resulted in the formation of a more ordered microphase-separated structure. Owing to the microphase separation of the hard cellulosic and soft PDL segments, all the AcCel_x-b-PDL-b-AcCel_x samples exhibited elastomer-like properties. Moreover, the decrease in DS improved toughness and suppressed stress relaxation. Furthermore, preliminary biodegradation tests in an aqueous environment revealed that the decrease in DS endowed AcCel_x-b-PDL-b-AcCel_x with greater biodegradability potential. This work demonstrates the usefulness of cellulose acetate-based TPEs as next-generation sustainable materials.

Anatase-cellulose acetate for reinforced desalination membrane with antibacterial properties

This study aimed to prepare antifouling and highly mechanical strengthening membranes for brackish and underground water desalination. It was designed from cellulose acetate (CA) loaded anatase. Anatase was prepared from tetra-iso-propylorthotitanate and carboxymethyl cellulose. Different concentrations of anatase (0.2, 0.3, 0.5, 0.6, 0.7, and 0.8)% were loaded onto CA during the inversion phase preparation of the membranes. The prepared membranes were characterized using Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM & EDX), mechanical properties, swelling ratio, porosity determination, and ion release. The analysis confirmed the formation of anatase on the surface and inside the macro-voids of the membrane. Furthermore, anatase loading improved the CA membrane's mechanical properties and decreased its swelling and porosity rate. Also, CA-loaded anatase membranes displayed a significant antibacterial potential against Gram-positive and Gram-negative bacteria. The results showed that the salt rejection of the CA/anatase films as-prepared varies considerably with the addition of nanomaterial, rising from 46%:92% with the prepared membranes under the 10-bar operation condition and 5 g/L NaCl input concentration. It can be concluded that the prepared CA-loaded anatase membranes have high mechanical properties that are safe, economical, available, and can stop membrane biofouling.

Cellulose acetate network via ion pre-anchored strategy for simultaneous regulation of uniform Mg2+ flux and ion conductivity

Hybrid LiMg batteries stand out by combining the rapid lithium diffusion kinetics and the advantages of magnesium. However, the uneven Mg deposits may result in continuous parasitic reactions and penetrate the separator. Herein, cellulose acetate (CA), with functional groups, was applied to engineer coordination with MOFs and construct the evenly-distributed and ample nucleation sites. Moreover, the hierarchical MOFs@CA network was fabricated via the metal ion pre-anchored strategy to regulate the uniform Mg²⁺ flux and improve ion-conductivity simultaneously. Furthermore, the hierarchical CA networks with well-ordered MOFs provided efficient MOF-to-MOF ion-transportation channels and served as ion sieves to inhibit anion transportation, thereby mitigating polarization. The super dendrite-inhibition and interfacial compatibility was confirmed and the assembled Mo₆S₈//Mg batteries exhibited high capacity about 105 mAh g^-1 and capacity decay of 4 % after 600 cycles at 30 C, which surpassed the state-of-the-art LMBs system employing Mo₆S₈ electrode. The fabricated GPE sheds fresh strategy for the design of CA-based GPEs and bright light on the promise of high-performance LMBs.

Valorizing industrial tobacco wastes within natural clays and chitosan nanocomposites for an ecofriendly insecticide

We report the engineering of insecticide films based on two mineral clays, montmorillonite and kaolinite, combined to chitosan and/or cellulose acetate originating from cigarette filter and subsequently impregnated with tobacco essential oil extracted from tobacco dust. Both binary composites, i.e. clay and chitosan or clay and cellulose acetate, and ternary composites containing clay, chitosan and cellulose acetate were prepared and characterized by XRD, DLS, ELS, and IR to investigate the nature of interactions within the composites. The two clay minerals showed different kinds of interaction with chitosan: intercalation in the case of Montmorillonite vs adsorption on the external surface for kaolinite. Secondly, the nicotine release from the composites films at different temperatures was studied by in-situ IR. The Montmorillonite composites, particularly the ternary one, showed a better encapsulation of nicotine which release was limited. Finally, the insecticidal activity of the composites was evaluated against the Tribolium castaneum a common wheat pest. The differences observed between montmorillonite and kaolinite composites were rationalized in relation to the nature of interaction between the components. The fumigant bioassay showed promising insecticidal effects in the case of the ternary composite cellulose acetate/chitosan/montmorillonite. Therefore, these eco-friendly nanocomposites can be used efficiently for the sustainable protection of stored cereals.

Spatio-temporal distribution of cigarette butt contamination in urban beaches with varying levels of use

This study assessed the extent of cigarette butt contamination on two urban beaches in Recife-PE (Pernambuco State, Brazil) with varying levels of use. The study considered degradation levels and evaluated whether the brands varied by time, space, and beaches use. Ten transects (1.5 m wide) and spaced 10 m apart, were delimited on the beaches investigated. Twelve collections were made between May 2021 and January 2022, and the collected cigarette butts were evaluated based on degradation level, mass, size, and brand. In total, 10,275 cigarette butts were collected on both beaches, with P1 accounting for 96.91% of the found cigarette butts. The density of cigarette butts on the beaches was directly proportional to the level of use, with 8.85 butts/m2 in P1 and 1.05 butts/m2 in P2. Eighteen brands were identified, with brand (A) being the most popular regardless of the area. Significant differences (p ≤ 0.05) were found when evaluating the amount of butts/m2; Sundays with high precipitation presented reduced values of butts; more occupied areas presented transects with higher amounts; abundance in the summer; morphometry with higher values recorded in newly discarded butts; predominance of more degraded butts and brand diversity. Despite the difference in the number of butts/m2 between the areas, it was possible to identify that their abundance is very expressive, and that the monitored beaches present a high exposure to the contaminant.

Cigarettes butt littering: The story of the world's most littered item from the perspective of pollution, remedial actions, and policy measures

Cigarettes butt (CB) is one of the most littered items on the planet. This paper critically analyzes the factors responsible for CB littering, and associated environmental ramifications, and reviews all the possible technical, behavioural, and policy-based solutions. Even while smoking has declined globally, middle-income nations have seen an increase in consumption, which may be related to increased affordability and a lack of public awareness. The smokers' individual beliefs and habits, environmental ignorance, covert littering as a result of social taboos associated with smoking, and behavioural gaps between intention and action might all be contributing factors to CBs' littering behaviour. The low biodegradability of cellulose acetate filters and toxic chemical leaching from CBs are the most important aspects of CB environmental toxicity. The small size and low economic value of CB contribute to the inefficiencies of current waste collection and management systems. The current research on CB valorisation includes fired-clay bricks, asphalt concrete, biofilms, sound absorber, cellulose pulp, pesticides, and insecticides as downstream mitigation strategies. This study highlights the urgent need for policymakers to enforce regulations enabling innovative cigarette designs, the creation of deposit-refund schemes, extended producer responsibility and stringent waste collection mechanisms. Adopting gentler marketing strategies and non-confrontational behavioural nudges could result in an overall reduction in CB pollution.

Cellulose acetate/silica composites: Physicochemical and biological characterization

Cellulose acetate is of remarkable scientific interest, becoming more useful when is used in obtaining of the composite materials containing nanoparticles, as result of its improved properties. Thus, cellulose acetate/silica composite films obtained by casting the solutions of cellulose acetate (CA)/tetraethyl orthosilicate (TEOS) in different mixing ratios were analyzed in this paper. The impact of TEOS addition, and implicitly of the silica nanoparticles on the mechanical strength, water vapor sorption properties and antimicrobial activity of the cellulose acetate/silica films were mainly monitored. The results of the tensile strength tests were discussed in correlation with data obtained from Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. It was found that samples with low TEOS content show improved mechanical strength compared to samples with high amounts of TEOS. The microstructural characteristics of the studied films affect their moisture sorption capacity so that the weight of the adsorbed water increases with the addition of TEOS. These features are complemented with the antimicrobial activity against Staphylococcus aureus and Escherichia coli bacterial species. The obtained data show that the cellulose acetate/silica films, and especially those with low silica content have improved properties that can recommend them for applications in the biomedical field.

Optimization of whole-cell bacterial bioreporter immobilization on electrospun cellulose acetate (CA) and polycaprolactone (PCL) fibers for arsenic detection

Arsenic contamination is a critical global problem, and its widespread environmental detection is becoming a prominent issue. Herein, electrospun fibers of cellulose acetate (CA) and polycaprolactone (PCL) were successfully fabricated and used as the support material for immobilization of arsenic-sensing bacterial bioreporter for the first time. To date, no attempt has been made to immobilize fluorescent whole-cell bioreporter cells on electrospun fibers for arsenic detection. CA and PCL electrospun fibers were fabricated via traditional electrospinning technique and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and contact angle meter. Following immobilization of the bacterial bioreporter cells, the immobilized bacteria were also characterized by viability assay using AlamarBlue. The effects of growth phase and cell concentration on the fluorescence response of fiber-immobilized arsenic bioreporters to arsenic were also investigated. After immobilization of arsenic bioreporters on 10 wt% PCL fiber, 91% of bacterial cells remained viable, while this value was 55.4% for cells immobilized on 12.5 wt% CA fiber. Bioreporter cells in the exponential growth phase were shown to be more sensitive to arsenic compared to aged cells. While both the electropsun PCL- and CA-immobilized bioreporters successfully detected 50 and 100 µg/L of arsenite (As (III)) concentrations, the PCL-immobilized bioreporter showed better fluorescence performance which should be investigated in future studies. This study helps to fill some gaps in the literature and demonstrates the potential for using electrospun fiber-immobilized arsenic whole-cell bioreporter for arsenic detection in water.

Life cycle assessment of end-of-life options for cellulose-based bioplastics when introduced into a municipal solid waste management system

The partial degradation of cellulose-based bioplastics in industrial treatment of organic fraction of Municipal Solid Waste (MSW) opened to the investigation of further disposal routes for bioplastics in the waste management system. For this purpose, the environmental footprint of three MSW management scenarios differing only for the bioplastics final destination (organic, plastic or mixed waste streams) was assessed through a Life Cycle Assessment (LCA) approach. Results revealed how the treatment of bioplastics with organic waste achieved the worst environmental performance (5.8 kg CO₂ eq/FU) for most impact categories. On the other hand, treatment with plastics and mixed waste achieved negative impact values (that mean avoided GHG emissions) of -9.8 and -7.7 kg CO₂ eq/FU respectively, showing comparable benefits from these scenarios. The key reason was the lower quality of compost obtained from the organic treatment route, which reduced the environmental credits achieved by the energy recovery during anaerobic digestion.

Experimental and simulated distribution and interaction of water in cellulose esters with alkyl chain substitutions

This study investigated the effect of the average length of substituted side chains in different cellulose esters on water sorption and the water association mechanism. For this purpose, a set of esters with a similar total degree of substitution was selected: cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. Dynamic vapor sorption was used to determine the effect of the side chain length on sorption, desorption, and the occurrence of water clustering. Since water association in the structure was of interest, molecular dynamics simulations were performed on cellulose acetate and cellulose acetate propionate. This study showed that cellulose acetate appears to be water-sensitive and experiences hysteresis upon water sorption, which was attributed to structural changes. The simulations also showed that water is screened out by the side chains and forms intermolecular hydrogen bonds, primarily to the carbonyl oxygen rather than the residual hydroxyl groups.

Cigarette: an unsung anthropogenic evil in the environment

The world's population is growing steadily, and this trend is mirrored by a sharp rise in the number of people who smoke cigarettes. Instead of properly disposing of their cigarette waste, most people simply toss them aside, leading to serious environmental consequences. According to previous statistics, in 2012 alone, 6.25 trillion cigarettes were consumed by 967 million chain smokers. Past studies have shown that up to 30% of global litter is made up of cigarette waste. These discarded cigarette butts are non-biodegradable and contain over 7000 toxicants such as benzene, 1,3-butadiene, nitrosamine ketone, N-Nitrosonornicotine, nicotine, formaldehyde, acrolein, ammonia, aniline, polycyclic aromatic hydrocarbons, and various heavy metals. These toxicants have a negative impact on the habitats of wildlife and can cause serious health problems such as cancer, respiratory disorders, cardiac issues, and sexual dysfunction. Although it is still unclear how littered cigarettes affect plant growth, germination, and development, it is clear that they have the potential to harm plant health. Just like single-use plastic, trashed cigarette butts are a critical new rising form of pollution that requires scientific attention for effective recycling and disposal management. It is important to properly dispose of cigarette waste to protect the environment and wildlife, as well as to prevent harm to human health.

Graphene nanoplatelet/cellulose acetate film with enhanced antistatic, thermal dissipative and mechanical properties for packaging

With the increased concern over environment protection, cellulose acetate (CA) has drawn great interests as an alternative for packaging material due to its biodegradability and abundant resources; whereas, the poor antistatic property and thermal conductivity restrict its application in packaging. In this work, we proposed a simple but effective strategy to produce high performance graphene nanoplatelet (GNP)/CA composite films via the consecutive homogenization and solvent casting processes. Relying on the spontaneous absorption of CA during homogenization, the GNP/CA produced shows an excellent dispersibility in the N,N-Dimethylformamide (DMF) solution and many fewer structural defects compared with GNPs alone. As a result, the composite films obtained exhibit simultaneously and significantly enhanced antistatic, heat dissipative and mechanical properties compared with CA. Specifically, the GNP/CA composite with the optimal formula has promising overall performances (namely, surface resistivity of 3.33 × 10⁷ Ω/sq, in-plane thermal conductivity of 5.359 W ( m · K ) , out-of-plane thermal conductivity of 0.785 W ( m · K ) , and tensile strength of 37.1 MPa). Featured by its promising overall properties, simple production processes and biodegradability, the as-prepared GNP/CA composite film shows a great potential for application in packaging.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10570-023-05155-2.

Polyphenolic-modified cellulose acetate membrane for bone regeneration through immunomodulation

To enhance the bioactivity of cellulosic derivatives has become an important strategy to promote their value for clinical applications. Herein, protocatechualdehyde (PCA), a polyphenolic molecule, was used to modify a cellulose acetate (CA) membrane by combining with metal ions to confer an immunomodulatory activity. The PCA-modified CA membrane has shown a significant radical scavenging activity, thereby suppressed the inflammatory response and created a favorable immune microenvironment for osteogenesis and mineralization. Moreover, addition of metal ions could further stimulate the osteogenic differentiation of stem cells and accelerate bone regeneration both in vitro and in vivo. This study may provide a strategy to promote the immunomodulatory activity of cellulose-based biomaterials for bone regeneration.

Determination of properties and environmental impact due to the inclusion of cigarette fibers in mortar: a new solution to mitigate the CB pollution

Cigarette butts generated are one of the major sources of total solid waste production and lead to environmental issues. This article has the objective of evaluating the effects of cellulose acetate microfibers (CAFs) sourced from discarded cigarette filters (CFs) as fiber reinforcement on the physico-mechanical properties and thermal conductivity of cementitious materials. To do so, mortar samples were prepared using different incorporated quantities of fibers (0.5, 1, 1.5, 2, 2.5, and 5% compared to the quantity of sand added to the mixture) and subjected to different tests to characterize the influence of CAFs on the microstructure of elaborated materials, considering the changes in workability time, compressive strength, flexural strength, density, water absorption, and microstructural analysis. Furthermore, the life cycle assessment (LCA) of mortar mixes in terms of CO₂ emissions is made. The results revealed that the increasing percentages of CAFs reduced the dry density and compressive strength, by approximately 1.62-51% and 37-69.64%, respectively, and a notable enhancement of insulation characteristics by about 5-47.5% was achieved. Microstructure analysis confirmed the experimental investigation and revealed that adding more than 1% of fibers resulted in a significantly low unit weight with greater entrapped air content. The studies prove the possibility of recycling cigarette butts for insulating cementitious matrix. In addition, applying mortar containing acetate cellulose fibers is recognized as a more environmentally friendly mixture in terms of reducing CO₂ emissions and could participate significantly in the achievement of SDGs.

An optimized acidic digestion for the isolation of microplastics from biota-rich samples and cellulose acetate matrices

Plastic pollution is a growing concern. To analyze plastics in environmental samples, plastics need to be isolated. We present an acidic/oxidative method optimized to preserve plastics while digesting synthetic cellulose acetate and a range of organics encountered in environmental samples. Cellulose acetate was chosen for optimization as it can be purchased as a reference material, can co-occur with plastics in environmental samples and, if it can be completely digested, is a potential filter material for the collection of nano- and micro-plastics from natural waters. Other forms of particulate organic matter (POM) were chosen to provide a range of chemistries that might alter digestion efficiency and due to the interest in the community of isolating plastics from samples where these organics occur. For instance, microalgal POM occurs in lake and ocean waters, riverine POM in rivers, and inclusion of tuna provides a test for the suitability of the method for isolating plastics from animal tissues. The method is a one-pot overnight (16-18 h) digestion in 5 M nitric acid with 0.3 M sodium persulfate heated to 80 °C. The method provides quantitative removal of cellulose acetate (exceeding detection limits), near quantitative removal of microalgal POM and Albacore tuna tissue (>99%), but only 86% of urban river POM, all while retaining >99% by mass of C-C bonded polymers polyethylene, polypropylene, and polystyrene and >96% by mass of polyethylene terephthalate. Fourier transform infrared spectroscopy (FT-IR) and %-C content analysis confirmed plastic polymer stability during digestion. However, some additives in appear susceptible to digestion with FT-IR results indicating the loss of N,N'-ethylenebis(stearamide) from polyethylene. This method provides a simpler and more effective method than many in the literature. We present recommendations for the application of this method, as well as limitations and areas for future improvement.

Time to kick the butt of the most common litter item in the world: Ban cigarette filters

Cigarette filters offer no public health benefits, are single-use plastics (cellulose acetate) and are routinely littered. Filters account for a significant proportion of plastic litter worldwide, requiring considerable public funds to remove, and are a source of microplastics. Used cigarette filters can leech toxic chemicals and pose an ecological risk to both terrestrial and aquatic ecosystems. Bottom-up measures, such as focusing on consumer behaviour, are ineffective and we need to impose top-down solutions (i.e., bans) if we are to reduce the prevalence of this number one litter item. Banning filters offers numerous ecological, socioeconomic, and public health benefits.

Improved performance of metal-organic frameworks loaded cellulose acetate based film for packaging application

Bio-nanocomposite-based packaging materials have gained significance due to their possible applications in food packaging. Cellulose acetate is a biopolymer obtained by acetylation of cellulose and has characteristics such as biocompatibility, biodegradability and high transparency. Introducing iron-based metal-organic frameworks offer good mechanical strength, unique surface area and both chemical and thermally stability, making them favourable as supporting materials in fabricating polymer-based packaging materials. Among them, Fe- (Material Institute Lavoisier) MIL-88A is an iron-based nontoxic metal-organic framework, integrated with cellulose acetate and spinach extract was added to the prepared material in different compositions and cast as film. The Spinach loaded, Fe- (Material Institute Lavoisier) MIL-88A integrated cellulose acetate film significantly enhanced the tensile strength, water vapour permeability, and anti-microbial activity. The prepared film is then characterized using a scanning electron microscope (SEM), Fourier transforms infrared spectrometer (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Further, studies on mechanical properties as well as degradation tests and real-time applications of the prepared films were carried out.

Synergistic effect of GO/ZnO loading on the performance of cellulose acetate/chitosan blended reverse osmosis membranes for NOM rejection

Declining freshwater resources along with their pollution are threatening the life existence on earth. To meet the freshwater demand, one of the most appropriate and possible ways which has been adopted all over the world is to reuse wastewater by removing its impurities. Among many water pollutants, natural organic matter (NOM) is found to be responsible as major precursor for the formation of other pollutants. Removal of NOM from wastewater is being done by using membrane filtration systems incorporated with certain nanofillers to increase membranes efficiency and permeability. In this study, novel nanocomposite reverse osmosis (RO) membranes were prepared using cellulose acetate and chitosan in N,N-Dimethyl formamide. Graphene oxide (GO) nanosheets and zinc oxide (ZnO) in different concentration were loaded to modify the membranes for tuning their RO performance. The confirmation of the functional groups is demonstrated by Fourier transform infrared spectroscopy which revealed the specific peaks indicating the formation of the nano-composite membranes. The surface morphology was studied by scanning electronic microscopy which shows a gradual transformation of the membrane surface from voids-free to macro-voids filled surface up to threshold concentration of GO and ZnO. The thermal properties of GO based membranes were analyzed using thermogravimetric analysis and differential scanning calorimetry. The uniform interaction of the GO and ZnO with polymers induced the remarkable thermal properties of the synthesized membranes. Permeate flux and contact angle measurements were considered to estimate their water content (96%) capacity and NOM rejection (96%) using 0.1 ppm humic acid solution. The permeate flux, NOM rejection and the water content changed directly with GO and inversely with ZnO wt% in the membranes up to GO5 (GO:0.14: ZnO:0.03) whereas the contact angle exhibited the inverse relationship with GO and ZnO concentration in casting solution of the synthesized membranes. Hence it can be concluded that prepared RO membranes are suitable for NOM rejection and recommended for water treatment.

CeO2@PU sandwiched in chitosan and cellulose acetate layer as Cs-CeO2@PU-CA triple-layered membrane for chromium removal

The single or blended polymer membrane lacks a few advantages based on the durability of the membrane. The novel triple-layered sandwich membrane Cs-CeO₂@PU-CA membrane is cast through the phase inversion technique for chromium removal. This approach involves an arrangement of the top layer as chitosan which acts as a protective layer, and the sandwich layer of CeO₂@PU membrane which acts as source for stability, and a supportive layer of cellulose acetate is arranged accordingly. The incorporation of cerium oxide nanoparticles into the polyurethane can create pores on the surface of the membrane due to the high aspect ratio of cerium oxide. The triple-layered arrangement shows higher porosity via water contact angle, the network of pores present on the membrane which is visible through morphology, and also the intermediate sandwich layer CeO₂@PU provided with better mechanical strength which would be significant for changes achieved in adsorption technique. The batch adsorption was carried out with various ppm of Cr(VI) solution. The effect of pH, contact time, initial concentration, and temperature were analyzed and optimized for determining efficiency of chromium removal. Furthermore, the suitable adsorption isotherm and kinetics of the system were also determined for better fit via Langmuir, Freundlich, Temkin, and Sips along with pseudo-first-order and pseudo-second-order. The efficiency in adsorption is due to the prominent presence of hydroxyl, carboxyl, and hydrophilic group in the prepared membrane. Thus, the resultant prepared membrane can act as a potential chromium removal substrate.

Preparation, optimization, and in vitro-in vivo evaluation of sorafenib-loaded polycaprolactone and cellulose acetate nanofibers for the treatment of cutaneous leishmaniasis

The most common form of leishmaniasis is cutaneous leishmaniasis (CL). The major difficulties in the treatment of leishmaniasis include emergence of resistance, toxicity, long-term treatment, and the high cost of the current drugs. Although the therapeutic effect of sorafenib (SF) has been demonstrated in both in vitro and in vivo models of Leishmania infection, the therapeutic applications are limited due to severe drug-related toxicity; this is, in turn, due to non-specific distribution in the body. Thus, topical delivery has the advantage of the site directed delivery of SF. This research study evaluated SF-loaded hybrid nanofibers (NFs) which were composed of polycaprolactone (PCL) and cellulose acetate (CA) for the CL topical treatment. Accordingly, SF-loaded hybrid NFs were prepared using the electrospinning method. Formulation variables including total polymer concentration, drug/polymer ratio, and CA concentration were optimized using a full factorial design. The prepared SF-loaded NFs were then characterized for morphology, diameter, encapsulation efficiency (EE)%, drug loading (DL) %, and percentage of release efficiency during a 24-h period (RE_24h%); the mechanical characteristics were also considered. The physical state of the drug in the optimized NF was evaluated by the X-ray diffraction analysis. Finally, its in vivo efficacy was determined in L. major-infected mice. The optimized formulation had a smooth, cylindrical, non-beaded shape fiber with a diameter of 281.44 nm, EE of 97.96%, DL of 7.48%, RE of 51.05%, ultimate tensile strength of 1.08 MPa, and Young's moduli of 74.96 MPa. The XRD analysis also demonstrated the amorphous state of SF in NF. Further, the in vivo results displayed the higher anti-leishmanial activity of the SF-loaded hybrid NF by efficiently healing lesion and successfully reducing the parasite burden. This, thus, indicated the potential of the clinical capability of the SF-loaded hybrid NF for the effective treatment of CL.

Composite nanofiber formation using a mixture of cellulose acetate and activated carbon for oil spill treatment

Oil and organic pollutants are significant disasters affecting the aquatic ecosystem and human health. A novel nanofiber composite from cellulose acetate/activated carbon (CA/AC) was successfully fabricated by the electrospinning technique. CA/AC nanofiber composites were prepared from 10% (w/v) polymer solutions dissolving in DMA/acetone ratio 1:3 (v/v) with adding three different percentages of AC (3.7, 5.5, and 6.7%) to the total weight of CA. The prepared CA/AC nanofiber composite morphology reveals randomly oriented bead-free fibers with submicron fiber diameter. CA/AC nanofiber composites were further characterized by TGA, DSC, and surface area analysis. Water uptake was investigated for fabricated fibers at different pH. Oil adsorption was conducted in both static (oil only) and dynamic (oil/water) systems to estimate the adsorption capacity of prepared composites to treat heavy and light machine oils. The results showed increased oil adsorption capacity incorporating activated carbon into CA nanofiber mats. The maximum sorption capacity reached 8.3 and 5.5 g/g for heavy and light machine oils obtained by CA/AC5.5 (AC, 5.5%). A higher oil uptake was reported for the CA/AC composite nanofibers and showed a constant sorption capacity after the second recycles in the reusability test. Of isotherm models, the most applicable model was the Freundlich isotherm model. The result of kinetic models proved the fit of the pseudo-second-order kinetic model to the adsorption system.

Properties of bacterial cellulose acetate nanocomposite with TiO2 nanoparticle and graphene reinforcement

Agricultural waste is considered a promising source for bacterial cellulose production. This study aims to observe the influence of TiO₂ nanoparticles and graphene on the characteristic of bacterial cellulose acetate-based nanocomposite membranes for bacterial filtration in waters. Bacterial cellulose was produced from the pineapple peel waste using fermentation process. High-pressure homogenization process was applied to reduce bacterial nanocellulose size and esterification process was carried out to produce cellulose acetate. Nanocomposite membranes were synthesized with reinforcement of TiO₂ nanoparticles 1 % and graphene nanopowder 1 %. The nanocomposite membrane was characterized using an FTIR, SEM, XRD, BET, tensile testing, and bacterial filtration effectiveness using the plate count method. The results showed that the main cellulose structure was identified at the diffraction angle 22° and the cellulose structure slightly changed at the peak of diffraction angles of 14° and 16°. In addition, the crystallinity of bacterial cellulose increased from 72.5 % to 75.9 %, and the functional group analysis showed that several peak shifts indicated a change in the functional group of membrane. Similarly, the surface morphology of membrane became rougher with the structure of mesoporous membrane. Moreover, adding TiO₂ and graphene increases crystallinity and bacterial filtration effectiveness of nanocomposite membrane.

Developing strong and tough cellulose acetate/ZIF67 intelligent active films for shrimp freshness monitoring

There is a growing demand for the development of intelligent active packaging films to maintain and monitor the freshness of meat food. Herein, nano Co-based MOF (ZIF67) with ammonia-sensitive and antimicrobial functions was successfully synthesized and then integrated into cellulose acetate (CA) matrix to prepare intelligent active films. The impacts of ZIF67 incorporation on the structure, physical and functional characteristics of CA film were fully investigated. The results demonstrated that the ZIF67 nanofillers were evenly dispersed in CA matrix, resulting in remarkable improvement on tensile strength, toughness, thermal stability, UV barrier, hydrophobicity and water vapor barrier ability of CA film. Furthermore, the prepared CA/ZIF67 films exhibited superb antimicrobial and ammonia-sensitive functions. The CA/ZIF67 intelligent films turned their color from blue at beginning to brown during progressive spoilage of shrimp. These results revealed that the CA/ZIF67 films with excellent antimicrobial and ammonia-sensitive functions could be applied in intelligent active food packaging.

Co-digestion of food waste and cellulose-based bioplastic: From batch to semi-continuous scale investigation

Only few studies on the behaviour of bioplastics in anaerobic co-digestion could be found in literature and most of them are conducted in batch mode. Despite the fact that continuous experiments confirm or add new insight to the findings acquired from batch ones, there is still lack of such studies. This work aims to cover this gap, carrying out a semi-continuous anaerobic co-digestion of food waste and cellulose acetate (which its behaviour under anaerobic environment is also quite unexplored). After a first evaluation of the potential methane production from each substrate at batch scale, the semi-continuous co-digestion of food waste and cellulose acetate was carried out in three configurations. During the semi-continuous process, a methane yield of 331 NmlCH₄/gVS was generated from the co-digestion of food waste and cellulose acetate while bioplastics specimens achieved a weight loss of about 45 %. The results were both lower than the one obtained from batch co-digestion, although methane production rates were comparable regardless of being fed with or without bioplastics. An increase was registered after 65 days of semi-continuous process, due to the accumulation of CA specimens. This confirms the different degradation trends between bioplastics and food waste.