Design and synthesis of organic polymers for molecular separation membranes

Heavy Metal Rejection Performance and Mechanical Performance of Cellulose-Nanofibril-Reinforced Cellulose Acetate Membranes

In this research, cellulose acetate (CA) and CA nanocomposite membranes, reinforced with mass fractions of cellulose nanofibrils (CNF), are prepared using the phase separation technique. The membranes are extensively characterized using several techniques: Fourier Transform Infrared (FTIR) spectroscopy confirms the chemical structures, while Scanning Electron Microscopy (SEM) reveals their surface morphology. Mechanical characterization is conducted to explore the mechanical behavior of the membranes under wet and dry conditions through tensile testing. The mechanical properties of CA and CA-CNF membranes are also estimated using the Mori-Tanaka mean-field homogenization method and compared to experimental findings. The flux performance for pure and dam water, assessed at 3 bar, demonstrates that CNF reinforcement notably enhances the CA membrane's performance, particularly in flux rate and fouling resistance. The CA membrane shows high efficiency in removing Fe2+, Ba2+, and Al3+ from dam water, while CA-CNF membranes exhibit a varied range of removal efficiencies for the same ions, with the 0.5 wt % CNF variant showing superior resistance to surface fouling. Additionally, while CNF increases tensile strength and stiffness, it leads to earlier failure under smaller deformations, especially at higher concentrations. This research provides a detailed assessment of CA and CA-CNF membranes, examining their chemical, structural, and mechanical properties alongside their effectiveness in water treatment applications.

Exploring the Frontier of Biopolymer-Assisted Drug Delivery: Advancements, Clinical Applications, and Future Perspectives in Cancer Nanomedicine

The burgeoning global mortality rates attributed to cancer have precipitated a critical reassessment of conventional therapeutic modalities, most notably chemotherapy, due to their pronounced adverse effects. This reassessment has instigated a paradigmatic shift towards nanomedicine, with a particular emphasis on the potentialities of biopolymer-assisted drug delivery systems. Biopolymers, distinguished by their impeccable biocompatibility, versatility, and intrinsic biomimetic properties, are rapidly ascending as formidable vectors within the cancer theragnostic arena. This review endeavors to meticulously dissect the avant-garde methodologies central to biopolymer-based nanomedicine, exploring their synthesis, functional mechanisms, and subsequent clinical ramifications. A key focus of this analysis is the pioneering roles and efficacies of lipid-based, polysaccharide, and composite nano-carriers in enhancing drug delivery, notably amplifying the enhanced permeation and retention effect. This examination is further enriched by referencing flagship nano formulations that have received FDA endorsement, thereby underscoring the transformative potential and clinical viability of biopolymer-based nanomedicines. Furthermore, this discourse illuminates groundbreaking advancements in the realm of photodynamic therapy and elucidates the implications of advanced imaging techniques in live models. Conclusively, this review not only synthesizes current research trajectories but also delineates visionary pathways for the integration of cutting-edge biomaterials in cancer treatment. It charts a course for future explorations within the dynamic domain of biopolymer-nanomedicine, thereby contributing to a deeper understanding and enhanced application of these novel therapeutic strategies.

Simultaneous Spin Coating and Ring-Opening Metathesis Polymerization for the Rapid Synthesis of Polymer Films

We report a highly controlled technique for the synthesis of polymer films atop a substrate by combining spin coating with ring-opening metathesis polymerization (ROMP), herein termed spin coating ROMP (scROMP). The scROMP approach combines polymer synthesis and deposition into one process, fabricating films of up to 36 cm2 in under 3 min with orders-of-magnitude reduction in solvent usage. This method can convert numerous norbornene-type molecules into homopolymers and random copolymers as uniform films on both porous and nonporous substrates. Film thickness can be varied from a few hundred nanometers to a few tens of micrometers based on spin speed and monomer concentration. The resulting polymers possess high MW (>100 kDa) and low polydispersity (PDI) (<1.2) values that are similar to ROMP polymers made in solution. We also devise a model to investigate the balance between convective monomer spin-off and polymer growth from the surface, which allows the determination of critical kinetic parameters for scROMP. Finally, translation of scROMP to porous supports enables the synthesis of thin film composite membranes that demonstrate the ability to dehydrate ethanol by pervaporation.

Advancement in Biopolymer Assisted Cancer Theranostics

Applications of nanotechnology have increased the importance of research and nanocarriers, which have revolutionized the method of drug delivery to treat several diseases, including cancer, in the past few years. Cancer, one of the world's fatal diseases, has drawn scientists' attention for its multidrug resistance to various chemotherapeutic drugs. To minimize the side effects of chemotherapeutic agents on healthy cells and to develop technological advancement in drug delivery systems, scientists have developed an alternative approach to delivering chemotherapeutic drugs at the targeted site by integrating it inside the nanocarriers like synthetic polymers, nanotubes, micelles, dendrimers, magnetic nanoparticles, quantum dots (QDs), lipid nanoparticles, nano-biopolymeric substances, etc., which has shown promising results in both preclinical and clinical trials of cancer management. Besides that, nanocarriers, especially biopolymeric nanoparticles, have received much attention from researchers due to their cost-effectiveness, biodegradability, treatment efficacy, and ability to target drug delivery by crossing the blood-brain barrier. This review emphasizes the fabrication processes, the therapeutic and theragnostic applications, and the importance of different biopolymeric nanocarriers in targeting cancer both in vitro and in vivo, which conclude with the challenges and opportunities of future exploration using biopolymeric nanocarriers in onco-therapy with improved availability and reduced toxicity.

Effect of Interlayer Construction on TFC Nanofiltration Membrane Performance: A Review from Materials Perspective

Polyamide (PA) thin-film composite (TFC) nanofiltration (NF) membranes, which are extensively utilized in seawater desalination and water purification, are limited by the upper bounds of permeability-selectivity. Recently, constructing an interlayer between the porous substrate and the PA layer has been considered a promising approach, as it may resolve the trade-off between permeability and selectivity, which is ubiquitous in NF membranes. The progress in interlayer technology has enabled the precise control of the interfacial polymerization (IP) process, which regulates the structure and performance of TFC NF membranes, resulting in a thin, dense, and defect-free PA selective layer. This review presents a summary of the latest developments in TFC NF membranes based on various interlayer materials. By drawing from existing literature, the structure and performance of new TFC NF membranes using different interlayer materials, such as organic interlayers (polyphenols, ion polymers, polymer organic acids, and other organic materials) and nanomaterial interlayers (nanoparticles, one-dimensional nanomaterials, and two-dimensional nanomaterials), are systematically reviewed and compared. Additionally, this paper proposes the perspectives of interlayer-based TFC NF membranes and the efforts required in the future. This review provides a comprehensive understanding and valuable guidance for the rational design of advanced NF membranes mediated by interlayers for seawater desalination and water purification.

Advances in 3D Printing for Tissue Engineering

Tissue engineering (TE) scaffolds have enormous significance for the possibility of regeneration of complex tissue structures or even whole organs. Three-dimensional (3D) printing techniques allow fabricating TE scaffolds, having an extremely complex structure, in a repeatable and precise manner. Moreover, they enable the easy application of computer-assisted methods to TE scaffold design. The latest additive manufacturing techniques open up opportunities not otherwise available. This study aimed to summarize the state-of-art field of 3D printing techniques in applications for tissue engineering with a focus on the latest advancements. The following topics are discussed: systematics of the available 3D printing techniques applied for TE scaffold fabrication; overview of 3D printable biomaterials and advancements in 3D-printing-assisted tissue engineering.

Morphology and water flux of produced cellulose acetate membranes reinforced by the design of experiments (DOE)

Cellulose acetate (CA) ultrafiltration membranes were successfully prepared using the non-solvent induced phase separation (NIPS) methodology. This technique is used to produce porous membranes for a large variety of applications. However, the formation of a dense skin during the process reduces membrane pure water flux (PWF). To overcome this issue, three parameters were investigated: CA/NMP (N-methyl-2-pyrrolidone) ratio in the casting solution, acetone (Ac)/water (W) ratio in the precipitation bath composition (PBC) and support material (glass/polyethylene). The effect of each factor on the mean pore size, water contact angle, porosity and PWF was supported by Taguchi design. The increase in the CA/NMP ratio reduced mean pore size and porosity. In contrast, there was an increase in porosity and hydrophilicity with increasing Ac/W ratio. The maximum value of PWF was obtained for membranes prepared using a PE support. ANOVA showed that most, but not all, factors had significant effects on the parameters measured.

Constructing interlayer to tailor structure and performance of thin-film composite polyamide membranes: A review

Thin-film composite (TFC) structured membranes based on polyamide (PA) chemistry is the gold standard of nanofiltration and reverse osmosis-based technologies for water purification and desalination. Constructing interlayer between porous substrate and PA layer is a promising strategy to address the ubiquitous trade-off between permeability and selectivity, which is typically encountered by conventional TFC PA membranes. The progress in the interlayer benefits the precise control of interfacial polymerization process, which therefore can tailor the structure and performance of advanced TFC PA membranes. This review critically summarizes the recent advances in TFC PA membranes mediated by interlayer. The mechanisms of interlayer regulating the IP process and PA structure are first discussed based on available literature. Structure and performance of novel TFC PA membranes based on three kinds of interlayers, i.e., organic coatings, nanomaterial and nanocomposite interlayers, are systematically reviewed. Finally, perspectives and future efforts needed are proposed for interlayer based TFC PA membranes. This review offers comprehensive understanding and useful guidance on the rational design of advanced membranes mediated by interlayers for desalination and water purification.

Role of Ionic Liquids in Composites in Analytical Sample Preparation

Ionic liquids (ILs) are a group of non-conventional salts with melting points below 100 °C. Apart from their negligible vapor pressure at room temperature, high thermal stability, and impressive solvation properties, ILs are characterized by their tunability. Given such nearly infinite combinations of cations and anions, and the easy modification of their structures, ILs with specific properties can be synthesized. These characteristics have attracted attention regarding their use as extraction phases in analytical sample preparation methods, particularly in liquid-phase extraction methods. Given the liquid nature of most common ILs, their incorporation in analytical sample preparation methods using solid sorbents requires the preparation of solid derivatives, such as polymeric ILs, or the combination of ILs with other materials to prepare solid IL-based composites. In this sense, many solid composites based on ILs have been prepared with improved features, including magnetic particles, carbonaceous materials, polymers, silica materials, and metal-organic frameworks, as additional materials forming the composites. This review aims to give an overview on the preparation and applications of IL-based composites in analytical sample preparation in the period 2017–2020, paying attention to the role of the IL material in those composites to understand the effect of the individual components in the sorbent.