Abstract

Chitin and chitosan are the second most abundant natural biopolymers in the curst of the earth. These polysaccharide biopolymers have a long linear chain-like structure connected with β-d glucosidic linkage with the functionalizable surface groups. Because of the structural features, these biomaterials exhibit unique physical, chemical, mechanical and optical properties, which contributed to the tunable and outstanding properties such as low density, high porosity, renewability, natural biodegradability, and environmental friendliness, etc. Chitin was synthesized via mechanical, chemical, chemo-mechanical, and eco-friendly biological methods and the deacetylation of the synthesized chitin carried for the preparation of chitosan. With the chemical modification used for the preparation of chitosan, there occurs some minor change in characteristics; however, most of the properties were relatable due to major similarities in the microstructures. The inherent antibacterial, non-toxic, and biodegradable properties with the ease of processibility of both polymer has the potential to become a successful alternative to its synthetic counterparts for energy and environmental applications. However, the poor mechanical and thermal properties in comparison to the conventional alternatives have restricted its widespread applications. This review addresses various areas such as extraction techniques of chitin and synthesis of chitosan, discussion of the common characteristics of both polymers together such as crystallinity, thermal properties, mechanical properties, hydrophilicity, and surface charge. Moreover, this review paper also addresses the common functionalization techniques for both polymer and the use of both unmodified chitin and chitosan along with their derivatives in environmental and energy applications such as air pollution, heavy metal adsorption, dye adsorption, biosensors, EMI shielding, fuel cell, solar cell, lithium-ion batteries, and biofuels.

Graphic Abstract

中文翻译：

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壳聚糖和壳聚糖基复合材料在能源和环境领域的应用：综述

摘要

几丁质和壳聚糖是地球上第二丰富的天然生物聚合物。这些多糖生物聚合物具有与β- d连接的长线性链状结构具有可官能化表面基团的糖苷键。由于结构特点，这些生物材料表现出独特的物理，化学，机械和光学特性，从而为低密度，高孔隙率，可再生性，自然生物降解性和环境友好性等可调节和突出的特性做出了贡献。机械，化学，化学机械和生态友好的生物方法以及用于制备壳聚糖的合成几丁质的脱乙酰作用。通过化学修饰制备壳聚糖，特性会发生一些细微变化。但是，由于微观结构的主要相似性，大多数特性是相关的。固有的抗菌，无毒，两种聚合物的易加工性以及可生物降解的特性，有可能成为其在能源和环境应用中合成替代物的成功替代品。然而，与常规替代品相比差的机械和热性能限制了其广泛的应用。本文综述了几丁质的提取技术和壳聚糖的合成，讨论了这两种聚合物的共同特征，例如结晶度，热性能，机械性能，亲水性和表面电荷。此外，

图形摘要