"Aero-Fib" - Investigation of synthesis, characterization and spinning of highly porous aero-cellulosic fibers for applications in technical textiles

用溶解在离子液体中的纤维素纺丝无孔纤维近年来引起了基础和工业研究的兴趣。研究表明，采用盐水合物熔体工艺从纤维素气凝胶中制备高多孔性和机械强度的大块材料是可行的。然而，离子液体既没有被用于生产高多孔纤维，也没有盐水合物熔体路线被系统地研究用于纤维生产。将研究两种溶解纤维素的方法——使用盐水合物熔体或离子液体——对航空纤维素纤维的生产和性能的影响。然后将开发的多孔纤维加工成适当的纺织品，随后将对其进行分析。因此，一种用于卫生用品和/或复合材料的过滤、高吸收剂的新型纤维材料得到了重视。高水平的孔隙率和机械强度是提高液体和颗粒吸收，保温和轻质性能的组合。ITA和DLR的初步实验已经证明了这种方法的可行性。研究将从生产纤维素气凝胶开始，通过制备盐水合物熔体或具有不同纤维素浓度的离子液体的溶液，然后将其干燥为散装材料。气凝胶的特性（如粘度、浓度）和干燥后的航空纤维素单体（如机械强度、孔隙度）将决定纤维纺丝试验的配方选择。随后，将开发和实施用于加工配方的专用纺纱设备。将对选定的配方进行可纺性测试。可纺配方将在不同的工艺参数（如拉丝速度、纺丝浴温度）下加工成纤维，并干燥成航空纤维素纤维。将分析纤维的特性（如机械强度、形态），以产生纺织应用的可能性，主要用于过滤或卫生产品。该提案的第二阶段研究了用航空纤维素纤维生产不同纺织结构（如非织造、针织或梭织）的能力。此外，机械改进航空纤维素纤维的可能性（例如使用交联剂）可以扩大这些纤维在复合材料领域的应用。该项目有望为如何控制纤维素在气凝胶中的排列提供见解，并展示这种材料在纤维和纺织品方面的潜力。

Spinning non-porous fibers from cellulose dissolved in ionic liquids has recently aroused the interest of fundamental and industrial research. It has been demonstrated that the production of highly porous and mechanically strong bulk materials from cellulosic aerogels using the salt-hydrate melt route is feasible. Yet, neither have ionic liquids been used for the production of highly porous fibers, nor has the salt-hydrate melt route been investigated systematically for fiber production.The two procedures for dissolution of cellulose – using salt-hydrate melts or ionic liquids – will be investigated with respect to the production and the properties of aero-cellulosic fibers. The developed porous fibers are then processed into adequate textiles, which will be analyzed subsequently. Hence a new fibrous material for filtration, superabsorbers in hygiene products and/or composites has been highlighted. A high level of porosity and mechanical strength is a combination that enhances liquid and particle absorption, thermal insulation and lightweight performance. Preliminary experiments of ITA and DLR have already demonstrated the feasibility of this approach.The investigation will start with the production of cellulosic aerogels by preparing solutions of salt-hydrate melts or ionic liquids with varying cellulose concentrations which subsequently will be dried as bulk materials. The properties of the aerogels (e.g. viscosity, concentration) and the dried aero-cellulosic monoliths (e.g. mechanical strength, porosity) will result in a selection of recipes for fiber spinning trials. Subsequently, an application-specific spinning equipment for processing the recipes will be developed and implemented. The selected recipes will be tested on spinnability. Spinnable recipes will be processed into fibers under varying process parameters (e.g. drawing speed, spin bath temperature) and dried into aero-cellulosic fibers. The properties of fibers (e.g. mechanical strength, morphology) will be analyzed to generate possibilities for textile applications, mainly for filtration or hygiene products.The second stage of this proposal investigates the capability of producing different textile structures (e.g. nonwoven, knitting or woven) with aero-cellulosic fibers. Additionally, the possibility to improve the aero-cellulosic fibers mechanically (e.g. using crosslinking agents) can expand the application of these fibers into the area of composites.The project is expected to provide insights on how to control cellulose arrangement in aerogels and to exhibit the potential of this material for fibers and textiles.