Reducing the physiological burden of individual protective clothing with nanocellulose

1.介绍目前的技术用于个人防护装备（IPE）服装提供了一个高水平的保护，对CBR战剂的军事人员。然而，穿着这种衣服的生理负担可能很高。一个主要的挑战是身体热量的去除，这可以通过使用透气织物来促进，因为这些织物允许来自汗液的水蒸气逸出西装的微气候。然而，如果透气性太高，保护水平可能会显著下降。因此，在不妨碍防护水平的情况下促进水蒸气从防护服中渗透出来是有意义的。受纳米纤维素的亲水性及其最近在增强非织造纤维和过滤方面的应用的启发，因此提出将纳米纤维素并入开发具有减少的生理负担的轻质多功能IPE服装中。项目目标：微生物合成的纳米纤维素，例如细菌纤维素（BC），将被用于这个特定的项目中，以生产纳米纤维素增强的IPE服装，从而使性能优于最先进的技术。开发一种廉价而简单的制造工艺，BC增强的IPE服装具有与现有技术相当的高透湿性和高尺寸排阻效率;2.检测并优化BC的液体控制性能，提高IPE服装的排斥性;3.设计和优化含有BC的IPE服装的多层结构，以最大限度地提高防护效率。2.研究方法2.1.用BC对IPE外衣织物进行改性，提出用BC涂覆IPE外衣层纱线，以提高IPE外衣的过滤效率。BC对纺织纤维的天然亲和力将允许BC附着在单个纺织纤维纱线水平处或跨多根纱线桥接。假设BC非织造物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。浆料浸渍法是将织物浸入BC悬浮液中并干燥，将用于生产BC涂层纱线。将改变浸渍时间和BC水悬浮液的稠度以研究和量化所得BC涂层的面密度。这些BC涂覆的织物将用Gurley密度计表征其透气性，并用模型微粒和明确定义的颗粒直径表征过滤效率。也可以进行扫描电子显微镜来研究BC-纺织纱线界面和其他特性，例如颗粒过滤和接触角。2.2.定制和增强IPE服装的化学吸附能力，BCIPE服装通常由活性炭负载内衬组成，以通过吸附去除潜在的有害蒸汽。然而，使该活性炭层的表面功能化以定制特定有害有机分子的吸附是具有挑战性的。相反，BC具有广泛的化学改性能力，因此有机会为特定的有机分子吸附设计定制的表面性能。例如，提出用（2，2，6，6-四甲基哌啶-1-基）氧杂环丁烷（克里思）氧化BC以将羧基引入到BC表面上。TEMPO氧化的BC显示出亲水性，因此会吸收大量的水分，并进一步最大限度地消除身体热量。

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.