intelligent diaphragm for biochemical protective clothing: self sensing, self responding, self cleaning, self repairing!

Biochemical protective clothing usually needs to deal with a very complex dangerous environment. Under special circumstances, it needs to be equipped with liquid tight or air tight protective clothing, which plays a comprehensive role in protecting all kinds of toxic and harmful liquid, gas, smoke, solid chemical substances, biological agents, military toxic gases and nuclear pollution. Therefore, in the future research of biochemical protective clothing, how to achieve better protective performance is as important as reducing weight and heat stress and improving the comfort of protective clothing

intelligent barrier material can make the surface of biochemical protective clothing have self sensing (“sensor” function), self response (“actuator” function) and self-adaptive ability to toxic and harmful substances. 1t can ensure the protective performance and adjust the air and moisture permeability of the protective clothing according to the external environment, or play the role of self disinfection or self-cleaning, 1t can greatly improve the protective performance and comfort of biochemical protective clothing

has a “barrier” function as barrier material.

‘s existing smart materials that can detect chemical and biological stimuli (including chemical properties, pH values, ionic strength, reaction heat, moisture, surface tension, biological surface functionalities, etc.) include conductive polymers, thermosensitive aerogels, chromium materials, active adsorbents and deformable materials. Among them, conductive polymer is a kind of biochemical intelligent protective sensor material with great application potential. For example, polymer doped polypyrrole, polythiophene and polyaniline (PAN1) can be used as sensors to detect volatile and liquid chemicals, The principle is: when these conductive polymers doped with special substances are exposed to the substances with oxidation / reduction effect, the “doping de doping” reaction will occur, and then the existence of harmful substances can be detected by monitoring the resistivity of the conductive polymers< The concentration of formaldehyde and acetaldehyde as low as 25mg / kg can be detected in the film embedded with polyaniline on MoO3 substrate in addition, enzyme can also be used to detect organophosphate chemicals. A sensor developed by agentase company combines acetylcholine, acetylcholinesterase, urea, urease and pH sensitive dye. At the same time, the product can quickly respond to temperature changes barrier film material with “actuator” function shape memory polymer material has the ability to maintain the temporary shape, and can restore the initial shape when subjected to appropriate external stimulation. 1t has many advantages, such as low density, large recoverable deformation, easy processing, adjustable deformation temperature, etc, As a kind of self response diaphragm material with “actuator” function, it has a wide application prospect. At present, the related research mainly focuses on thermally induced shape memory polymer materials. For example, shape memory polyurethane can keep warm with low permeability at low temperature (< TG) and heat dissipation with high permeability at high temperature (> TG), so as to fully improve the wearing comfort of the fabric. 1t is also observed that the shape memory polyurethane has a humidity sensitive effect, which means that the permeability of the shape memory polyurethane barrier film can also be adjusted by the change of humidity< At present, the commercialized shape memory polyurethane materials include the shape memory polyurethane thermosensitive breathable film developed by Mitsubishi Heavy 1ndustries (SMP technologies) and the shape memory polyurethane thermosensitive breathable film developed by Ahlstrom (OSLON) of Finland The air permeable integral film is sandwiched between two layers of superfine fiber spunbonded polypropylene nonwovens , in addition, the electrically immobilization nano porous polymer membrane prepared by grafting ionic gel also shows great potential in biochemical protective clothing. Under the action of electric field and application, the ionic gels in nanopores expand and contract, which can adjust the pore size and improve the permeability. The barrier principle of br/>
grafted ionic gel pet nanoporous membrane

adaptive barrier membrane and its application in biochemical protective clothing

adaptive intelligent material can provide immediate protection for wearers in response to external stimuli, such as self-cleaning function or self repairing function, which can clean harmful chemicals on the surface in time. Or repair the surface defect of protective clothing, prevent the invasion of harmful substances, and realize more intelligent protection

LLNL developed a membrane material with carbon nanotube moisture conducting holes

in 2016, Lawrence Livermore National Laboratory (LLNL) developed a membrane material called “second skin”. This material has aligned carbon nanotube moisture conducting holes with size less than 5nm, and has better air permeability than Gore-Tex membrane material. At the same time, because the size of biological virus is usually larger than 10 nm, it has a good barrier against the invasion of biological virus. 1n order to prevent the invasion of smaller harmful chemicals, researchers are using chemical responsive functional groups to modify the surface of carbon nanotube films, so as to achieve the selective barrier of harmful chemicals. At the same time, researchers are also working on another interesting “self-cleaning” defense method, that is, when it reacts with harmful chemicals, the surface membrane material will fall off automatically to achieve the purpose of self-cleaning. 1t is reported that the research, funded by the Defense Threat Reduction Agency (dtra), will be preliminarily evaluated in early 2018 and is expected to be used in its future biological protective clothing system

for more information, please refer to the article “new progress in research and application of textiles for intelligent safety protection” in textile Guide (supplement of industrial textiles)

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