Reducing the physiological burden of individual protective clothing with nanocellulose

1.介绍目前用于个人防护装备(IPE)服装的技术已经为军事人员提供了针对CBR战剂的高水平保护。然而，穿这样的衣服可能会带来很高的生理负担。一个主要的挑战是人体热量的排出，这可以通过使用透气面料来促进，因为透气面料可以让汗水中的水蒸气逃脱西装的小气候。然而，如果透气性太高，防护水平可能会显著下降。因此，在不阻碍保护水平的情况下，促进水蒸气从西装中渗透出来是有意义的。受纳米纤维素的亲水性及其在增强非织造布纤维和过滤性能方面的最新应用的启发，人们建议将纳米纤维素用于开发一种轻便、多功能、减轻生理负担的IPE服装。项目目标：微生物合成的纳米纤维素，例如细菌纤维素(BC)，将在这个特定的项目中使用，以生产一种纳米纤维增强的IPE服装，从而提高其性能。主要目标是：1.开发一种廉价和简单的制造工艺，使BC增强型IPE服装具有与最先进水平相当的高透湿性和高尺寸排斥效率；2.检查和优化BC的液体控制性能，增加IPE服装的排斥性；3.设计和优化加入BC的IPE服装的多层结构，以最大限度地提高保护效率。2.研究方法2.1。提出了用BCIT对IPE外衣织物进行改性，以提高IPE服装的过滤效率，方法是在外衣纱线上涂覆BC。BC对纺织纤维的天然亲和力将使BC能够在单一纺织纤维纱线水平上附着，或者跨越多根纱线桥接。据推测，BC非织造布将在织物结构内形成屏障，以减少、过滤或消除有机分子或微粒的通过。浆料浸渍方法是将织物浸入BC悬浮液中并烘干，用于生产BC涂层纱线。浸渍时间和BC-水悬浮液的浓度都将改变，以调查和量化所得BC涂层的面密度。这些BC涂层织物将用格雷密度计表征其透气性，并使用模型微粒和明确定义的微粒直径来表征过滤效率。扫描电子显微镜也可以用来研究BC-纺织纱线的界面和其他性质，如颗粒过滤和接触角。2.2.用BCIPE服装定制和增强IPE服装的化学吸附能力通常包括负载活性碳的内衬，以通过吸附去除潜在的危险蒸汽。然而，将这种活性碳层的表面功能化以适应特定危险有机分子的吸附是具有挑战性的。相反，BC具有广泛的化学修饰能力，因此有机会为特定的有机分子吸附设计定制的表面属性。例如，有人建议用(2，2，6，6-四甲基哌啶-1-基)氧自由基(TEMPO)氧化BC，以便在BC表面引入羧基。节拍氧化的BC具有亲水性，因此会吸收大量的水分，从而最大限度地促进身体热量的排出。

1. Introduction The current technology used in individual protective equipment (IPE) apparel has provided a high level of protection against CBR warfare agents for military personnel. However, the physiological burden of wearing such clothing can be high. One major challenge is the removal of body heat, which could be facilitated by the use of air-permeable fabrics as these allow water vapour derived from sweat to escape the microclimate of the suit. However, if the air-permeability is too high the levels of protection can fall significantly. Hence, there is an interest in promoting the permeation of water vapour out of the suits without impeding the level of protection. Inspired by the hydrophilic nature of nanocellulose and their recent applications in enhancing nonwovens fibres and filtrations, it is thus proposed to incorporate nanocellulose in developing a light and multifunctional IPE costume with reduced physiological burden. Project aims:Microbially-synthesised nanocellulose, e.g. bacterial cellulose (BC), would be employed in this particular project to produce a nanocellulose-enhanced IPE garment with resulting performance improvements over the state-of-the-art. The key objectives are:1. To develop a cheap and simple manufacturing process BC-enhanced IPE garments with high moisture permeability and high size-exclusion efficiency comparable to the state-of-the-art;2. To examine and optimise the properties of BC for liquid control, increasing the repellence of the IPE garments;3. To design and optimise the multi-layer configuration of IPE garment incorporating BC to maximised protection efficiency. 2. Research methodology2.1. Modification of textile fabric in the exterior garment of IPE with BCIt is proposed to improve the filtration efficiency of the IPE clothing by coating the yarns of the exterior garment layer with BC. The natural affinity of BC to textile fibres would allow BC to attach either at a single textile fibre yarn level or to bridge across multiple yarns. It is hypothesized that BC nonwoven would form a barrier within the fabric structure so as to reduce, to filter or to eliminate the passage of organic molecules or micro-particles. Slurry dipping method, in which fabrics will be dipped into a BC suspension and dried, will be employed to produce BC-coated yarns. Both the dipping time and the consistency of BC-in-water suspension will be varied to investigate and quantify the areal density of the resultant BC coating. These BC coated fabrics would be characterised for their air permeability with Gurley densometer and filtration efficiency with model micro-particulates and well-defined particle diameter. Scanning electron microscopy might also be conducted to study the BC-textile yarn interface and other properties such as particulate filtration and contact angles. 2.2. Tailoring and enhancing the chemisorption capability of IPE garment with BCIPE garments often consist of activated carbon loaded inner lining to remove potentially hazardous vapours through adsorption. However, it is challenging to functionalise the surface of this activated carbon layer to tailor the adsorption of specific hazardous organic molecule. On the contrary, BC possesses a broad chemical modification capacity and has thus exhibited opportunities to design bespoke surface properties for specific organic molecules adsorption. For instance, it is proposed to oxidise BC with (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl (TEMPO) in order to introduce carboxylic groups onto the BC surface. TEMPO-oxidised BC has shown to be hydrophilic and would therefore absorb significant amount of moisture and further maximise body heat removal.