ABSTRACT
Clothing is a person’s second skin, since it covered great parts of the body and having a large surface area in contact with the environment. Therefore, clothing is proper interface between environment and human body, and could act as an ideal tool to enhance personal protection. Over the years, growing concern regarding health and safety of persons in various sectors, such as industries, hospitals, research institutions, battlefields, and other hazardous conditions has led to intensive research and development in field of personal protective clothing. Nowadays, there are different types of protective clothing. The simplest and most preliminary of this equipment is made from rubber or plastic that is completely impervious to hazardous substances, air and water vapor. Another approach to protective clothing is laminating activated carbon into multilayer fabric in order to absorb toxic vapors from environment and prevent penetration to the skin [1]. The use of activated carbon is considered only a short term solution because it loses its effectiveness upon exposure to sweat and moisture. The use of semi-permeable membranes as a constituent of the protective material is another approach. In this way, reactive chemical decontaminants encapsulates in microparticles [2] or fills in microporous Hollow fibers [3]. The microparticle or fiber walls are permeable to toxic vapors, but impermeable to decontaminants, so that the toxic agents diffuse selectively into them and neutralize. All of these equipments could trap such toxic pollutions but usually are impervious to air and water vapor, and thus retain body heat. In other words, a negative relationship always exists between thermal comfort and protection performance for currently available protective clothing. For example, nonwoven fabrics with high air permeability exhibit low barrier performance, whereas microporous materials, laminated fabrics, and tightly constructed wovens offer higher level of protection but lower air permeability. Thus, there still exists a very real demand for improved protective clothing that can offer acceptable levels of impermeability to highly toxic pollutions of low molecular weight, while minimizing wearer discomfort and heat stress [4].
