Preparation and preservation properties of the chitosan coatings modified with the in situ synthesized nano SiOx

The chitosan coatings modified with the in situ synthesized nano SiOx were prepared and characterized, and the gas permeabilities and mechanical properties of the chitosan coatings were measured simultaneously. The SiOx dosage affects the micro morphology and microstructure of the chitosan coatings. The results show that in-situ synthesis method is conducive to nano SiOx dispersion. In the coatings, the particles size and amount are increased with nano SiOx dosage, and serious particles aggregation and coarse cross section are presented at nano SiOx dosage of 0.07%. Moreover, the strong hydrogen-bonds are formed between nano SiOx and chitosan molecule, and original structures of the chitosan are disorganized. The nano SiOx connect with chitosan with chemical bonds, and the chitosan structure in C=O bond and amide. are slightly affected. The gas permeabilities and mechanical properties of the coatings are affected by the dosage of nano SiOx, and the optimal nano SiOx dosage is 0.03%. The preservation properties of the chitosan coatings on the Sciaenops ocellatus are remarkable, and that of in situ synthesis nano SiOx chitosan coatings is more superior. Therefore, the chitosan coatings modified by in situ synthesized method may be a promising method to improve the preservation properties of the chitosan coatings. (C) 2015 Elsevier Ltd. All rights reserved.