Figerez Stelbin Peter, Patra Sudeshna, Rajalakshmi G, Narayanan Tharangattu N
Tata Institute of Fundamental Research - Hyderabad, Sy. No. 36/P Serilingampally Mandal, Gopanapally Village, Hyderabad - 500046, India.
Oxf Open Mater Sci. 2021 Mar 2;1(1):itab003. doi: 10.1093/oxfmat/itab003. eCollection 2021.
Respiratory masks having similar standards of 'N95', defined by the US National Institute for Occupational Safety and Health, will be highly sought after, post the current COVID-19 pandemic. Here, such a low-cost (∼$1/mask) mask design having electrostatic rechargeability and filtration efficiency of >95% with a quality factor of ∼20 kPa is demonstrated. This filtration efficacy is for particles of size 300 nm. The tri-layer mask, named PPDFGO tri, contains nylon, modified polypropylene (PPY), and cotton nonwoven fabrics as three layers. The melt-spun PPY, available in a conventional N95 mask, modified with graphene oxide and polyvinylidene fluoride mixture containing paste using a simple solution casting method acts as active filtration layer. The efficacy of this tri-layer system toward triboelectric rechargeability using small mechanical agitations is demonstrated here. These triboelectric nanogenerator (TENG)-assisted membranes have high electrostatic charge retention capacity (∼1 nC/cm after 5 days in ambient condition) and high rechargeability even in very humid conditions (>80% RH). A simple but robust permeability measurement set up is also constructed to test these TENG-based membranes, where a flow rate of 30-35 L/min is maintained during the testing. Such a simple modification to the existing mask designs enabling their rechargeability external mechanical disturbances, with enhanced usability for single use as well as for reuse with decontantamination, will be highly beneficial in the realm of indispensable personal protective equipment.
由美国国家职业安全与健康研究所定义的具有类似“N95”标准的呼吸面罩，在当前新冠疫情之后将备受追捧。在此，展示了一种低成本（约1美元/个面罩）的面罩设计，其具有静电再充电能力，对300纳米大小颗粒的过滤效率大于95%，品质因数约为20千帕。这种三层面罩名为PPDFGO tri，包含尼龙、改性聚丙烯（PPY）和棉质无纺布作为三层。在传统N95面罩中使用的熔喷PPY，通过简单的溶液浇铸法用氧化石墨烯和含糊剂的聚偏二氟乙烯混合物进行改性，用作活性过滤层。在此展示了这种三层系统利用小机械振动实现摩擦电再充电的功效。这些摩擦电纳米发电机（TENG）辅助的膜具有高静电荷保持能力（在环境条件下5天后约为1纳库仑/平方厘米），即使在非常潮湿的条件下（相对湿度>80%）也具有高再充电能力。还构建了一个简单但坚固的透气性测量装置来测试这些基于TENG的膜，测试期间保持30 - 35升/分钟的流速。对现有面罩设计进行如此简单的改进，使其能够通过外部机械干扰进行再充电，同时增强了一次性使用以及与去污剂一起重复使用的可用性，这在不可或缺的个人防护装备领域将非常有益。
