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

纤维素在离子液体中溶解后纺制无孔纤维，近年来引起了基础研究和工业研究的兴趣。已经证明，使用盐-水合物熔融路线从纤维素气凝胶生产高度多孔且机械强度高的散装材料是可行的。然而，既没有离子液体被用于生产高度多孔的纤维，也没有盐-水合物熔体路线进行了系统的研究，纤维素的生产。两个程序的溶解纤维素-使用盐-水合物熔体或离子液体-将在航空纤维素纤维的生产和性能方面进行研究。然后将开发的多孔纤维加工成合适的纺织品，随后将对其进行分析。因此，用于过滤、卫生产品和/或复合材料中的超吸收剂的新纤维材料已经被强调。高水平的孔隙率和机械强度是增强液体和颗粒吸收、隔热和轻质性能的组合。ITA和DLR的初步实验已经证明了这种方法的可行性。研究将从制备具有不同纤维素浓度的盐水合物熔体或离子液体溶液的纤维素气凝胶开始，随后将其干燥为散装材料。气凝胶的性质（例如粘度、浓度）和干燥的空气纤维素整料（例如机械强度、孔隙率）将导致选择用于纤维纺丝试验的配方。随后，将开发和实施用于处理配方的特定应用的纺丝设备。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（例如拉伸速度、纺丝浴温度）下加工成纤维，并干燥成航空纤维素纤维。纤维的性能（如机械强度、形态）将被分析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、针织或机织）的能力。此外，通过机械方法（如使用交联剂）对纤维素纤维进行改性，可以将纤维素纤维的应用扩展到复合材料领域。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.