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Chitosan (C) and zein (Z) were used to develop bilayer films with a characteristic one-way water barrier using a layer-by-layer (LBL) casting method. The effects of mass ratios (C:Z 1:1 , C:Z 1:2 , C:Z 1:3 , C:Z 3:1 , C:Z 2:1) on the microstructure and physicochemical properties of bilayer films were investigated. Bilayer films had uniform microstructures, and C:Z = 1:3 showed a firmer structure as the Z aggregates were distributed in the continuous phase of C. The intermolecular interactions between the C and Z layers were observed using FTIR and XRD analysis. TGA demonstrated that adding Z layer enhanced the thermal stability of C films. LBL coating gave the C/Z bilayer film an increased elongation and tensile strength, as well as a decreased water vapor and oxygen permeability, especially for C:Z = 1:3 which had better properties. The results suggested that C and Z bilayer films may be a promising material for food packaging with the desired water resistance. [Display omitted] • A bilayer film based on chitosan and zein was fabricated by LBL casting method. • Physicochemical property can be tuned by the zein layer. • The bilayer films showed excellent water resistance and mechanical properties. • The C:Z 1:3 films had better mechanical and barrier properties. [ABSTRACT FROM AUTHOR]

Polymer–clay nanocomposite hydrogel films (PCNCHFs) were prepared from caboxymethyl cellulose, polyvinylpyrrolidone, agar and nanosepiolite clay (0, 0.3, 0.5, 0.7, 0.9 and 1.5% reinforcement) by treating thermally in a simple, rapid, and inexpensive route. The PCNCHFs and its 5-fluorouracil (FU)-loaded composites (PCNCHFs@FU) were tested for FU release and characterized by FTIR, XRD, FE-SEM, EDX, DSC, and TGA analyses to investigate their structural, morphological, and thermal properties. The nanosepiolite-loaded polymer composites (PCNCHF1 to PCNCHF5) exhibited higher tensile strength than the pristine polymer hydrogel (PCNCHF0); consequently, the thermal properties (glass- and melting-transition) were improved. The PCNCHFs@FU demonstrated prolonged FU release at pH 7.4 for 32 h. The biocompatibility of PCNCHFs was tested against human skin fibroblast (CCDK) cells. The viability of cells exposed to all PCNCHFs was >95% after 72 h of culture. The live/dead assay show the proliferation of fibroblast cells, confirming the biocompatibility of the hydrogels. The pH-sensitive PCNCHFs@FU release could be suitable for drug release in cancer therapy, and the developed PCNCHFs may also be useful for tissue engineering, food packaging, and other biological applications. [Display omitted] • CMC-based clay hydrogels (PCNCHFs) prepared by moist-heat ensuing solution casting. • PCNCHFs exhibit higher thermal, mechanical, swelling, and FU release properties. • PCNCHF5 showed higher (78 MPa) tensile strength than PCNCHF0 (50 MPa). • PCNCHF5 revealed higher FU release compared to PCNCHF0 at pH 7.4 and 1.2. • The non-toxic behavior of PCNCHFs against CCDK cells confirm their biocompatibility. [ABSTRACT FROM AUTHOR]

Nano-chitosan (NCH), nano-cellulose (NCL) and cellulose derivative are biodegradable biopolymer. Nano-chitosan or nano-cellulose at different concentrations (0.1, 0.5 and 1%) incorporated in carboxymethyl cellulose (CMC) film solution using casting methods. Both CMC/NCH and NCL decreased physical properties (water solubility, moisture content and moisture absorption) especially in concentration of 1%. However, these properties in CMC/NCH were significantly (p < 0.05) lower than CMC/NCL. Water vapor permeability of polymer and nanofiller decreased when nanocomposite concentration increased. Tensile strength and Elongation at break improved in nanocomposite film by increasing concentration. Thermal properties of CMC/NCH were significantly (p < 0.05) lower than CMC/NCL. Emersion of crystalline peaks in X-ray analyses certified the presence of nanofiller in polymer. However, in high content (1%) cause to create aggregation of nanofiller in CMC film. Finally antibacterial activity against five pathogens was studied and good effective inhibition on CMC/NCH was observed while CMC/NCL had no inhibitory effect. These results show that use of CMC/NCH as a biocompatible film has more advantages than CMC/NCL biopolymer. Unlabelled Image • Incorporation of NCH and NCL to CMC improved WVP and mechanical properties of film. • The CMC films with various contents of NCH could inhibit the pathogens tested. • CMC/NCH films had better activities compared to CMC/NCL. • The CMC nanocomposite films have a potential for application in food packaging. [ABSTRACT FROM AUTHOR]

This study investigates the influence of various fillers on the properties of carrageenan, a natural polymer derived from red seaweed. Despite its potential for enhanced biocomposite film development, carrageenan faces challenges related to strength. The incorporation of nanoclay into the carrageenan film resulted in a significant increase in film thickness from 0.026 to 0.068 mm. The UV light transmission value for the carrageenan film alone was measured at 30.9 %, whereas films containing 5 wt% of Tetraethyl orthosilicate (TEOS), 3-Aminopropyltriethoxysilane (APTES), and nanoclay exhibited reduced transmission values of 23 %, 18 %, and 1 %, respectively. Notably, the tensile strength of the unfilled carrageenan film was 38.4 MPa, which increased to 38.6, 57, and 60 MPa upon the addition of 3 wt% of nanoclay, APTES, and TEOS fillers, respectively. All fillers contributed to improved tensile strength, with TEOS demonstrating the highest enhancement. The optimal filler content was determined to be 3 wt%. Regarding thermal properties, films containing TEOS displayed higher thermal stability compared to those with APTES, while films incorporating nanoclay exhibited the lowest stability. Findings provide insights into the effects of different fillers on the mechanical, physical and thermal properties of carrageenan films, supporting the development of improved biocomposite materials suitable for application in food packaging. • Nanoclay, TEOS and APTES were used to modify of the carrageenan film. • Silane-containing films have good interaction with the biopolymer matrix. • Nanoclay-containing films performed excellent in the case of UV transmittance. • Nanoclay-containing films showed better contribution to thermal stability. • Incorporation of the fillers in biopolymers resulted in higher tensile strength. [ABSTRACT FROM AUTHOR]

Nano-bacterial cellulose (BC), as a reinforcing agent, was used to prepare the agar-based edible films. Effects of BC content (0, 3, 5, 8 and 10%, wt% based on the agar) on the rheological properties of film-forming solution (FFS), and on structure, morphology, crystallinity, and thermal properties of films were investigated. Results of rheological and FTIR analyses revealed that interactions between BC and agar were formed through hydrogen bonds. The crystallinity and the thermal stability of films were improved by addition of BC analyzed by XRD and TGA, respectively. Compared with high BC concentrations (8–10%), a good dispersion of BC at low concentrations (3–5%) in the films was observed by SEM. Moreover, BC addition (10%) significantly decreased moisture content (MC), water solubility (WS) and water vapor permeability (WVP) by 60.4%, 13.3% and 25.7%, respectively. The tensile strength (TS) of films increased from 22.10 to 44.51 MPa after addition of BC (0–10%), whereas the elongation at break (EAB) initially increased with increasing BC concentrations (0–5%), and then decreased with further addition of BC (8–10%). Consequently, agar-based edible films reinforced by moderate nano-BC have the potential as a packaging film for food products. [ABSTRACT FROM AUTHOR]