Recent advances in chitin based materials constructed via physical methods

Chitin derived from the seafood wastes such as waste crab, shrimp and lobster shells is abundant and renewable, and will become one of the most important chemical raw materials. The construction of novel polymer materials via physical approaches and green technology from raw chitin is a sustainable pathway and beneficial to the green development of our world. This review is thus completed with aims to attract more scientists and researchers to devote to the scope of green polymers and contribute to the survival, health and development of human being. In this article, the novel chitin materials fabricated from chitin nanocrystals as well as via direct dissolution/regeneration of chitin are summarized, with 244 references. Specifically, the main content can be divided as follows: origin and structure of chitin; novel chitin solvents, dissolution mechanism and chain conformation; chitin nanocrystals/nanofibers as well as relevant functional materials; chitin materials fabricated via physical dissolution/regeneration including hydrogels/aerogels, membranes/films, fibers, microspheres/beads, as well as their potential applications in biomaterial, electrochemistry, energy storage, separation/absorption, catalyst carrier and textile materials. More involvements from government, enterprise, university and institute in the green conversion of natural polymer would be expected in the future, to build a world with sustainability. (C) 2018 Elsevier B.V. All rights reserved.