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In order to reduce the environmental pollution caused by plastic packaging, the development of biodegradable high-performance packaging materials has become a research hotspot. Cellulose is a promising food packaging material, but it usually lacks sufficient ultraviolet (UV) shielding property and mechanical strength. In this work, rectorite microplates were incorporated into the cellulose matrix by a facile blending method to fabricate the composite films. The structure and properties of the composite films were characterized by FT-IR, X-ray diffraction, scanning electron microscopy, UV–vis and mechanical properties test etc. The results indicated that rectorite microplates were uniformly distributed in the cellulose matrix. The blocking percentages for UVA and UVB for the cellulose/rectorite composite film with 14 wt% rectorite content (RCRF-14) could reach as high as 97.8 % and 96.0 %, respectively, showing a good UV shielding property. Meanwhile, the addition of rectorite obviously improved the mechanical properties and decreased the water vapor and oxygen permeabilities of the cellulose film, showing a potential application as a sustainable food packaging material. [ABSTRACT FROM AUTHOR]

Bulk homogeneous polyelectrolyte complex hydrogels (PCH) are difficult to prepare due to the flocculation effect between polyelectrolytes with opposite charges. Herein, novel chitosan/sodium polyacrylate (PAAS) polyelectrolyte complex hydrogels (CPG) were fabricated successfully by cross-linking chitosan and PAAS with epichlorohydrin (ECH) through inhibiting protonation effect of chitosan in alkali/urea aqueous solution. The swelling behaviors of CPG were studied systematically in different solutions. The equilibrium swelling ratio of chitosan hydrogel in water increased dramatically from 46.3 to 404.8 g/g by the introduction of PAAS. CPG exhibited different swelling ratios towards different pH solutions, physiological solutions and salt solutions with different concentrations, showing obvious smart responsive properties. Moreover, CPG hydrogels exhibited relatively high compressive strength, good biocompatibility and in vitro biodegradability. Therefore, this work provided a novel PCH and shed light on the fabrication of other PCH, showing potential applications in the fields of agriculture, foods, tissue engineering and drug delivery. [ABSTRACT FROM AUTHOR]