An exponential rise in air-pollution is a major concern for not only the health and well-being of all life forms but also the environment, swift and appropriate solutions are a need of the hour. Major components of these pollutants are particulate matter (PM), volatile organic molecules and gases such as COx, NOx and SOx. The PM are composed of both organic and inorganic species, minerals (such as calcite, dolomite, anorthite and feldspar)1 and soil dust PM are spatially concentrated, unlike gases, thereby affecting the local environment.2 Cloud condensation and haze are some of the major consequences of these PM. Exposure to these PM caused 4.2 million deaths globally and is considered to be the fifth as a major factor in contributing for global mortality rate.3 This seminar gives an overview of the understanding of the physical and chemical composition of dust by collecting dust on simple substrates like cotton, silk, leather and nylon were studied. This dust was collected in both active and passive modes. An in-situ observation of the impact and growth dynamics of PM on glass surfaces using a long-working distance microscope coupled to a high-speed camera. Chemically functionalized electrospun nanofibers possess surface charges, due to this an enhancement in the filtration efficiency of ~ 93 % these PM of size 0.3 μm was noted.4 These were capable in capturing model VOCs such as aniline, toluene, tetrahydrofuran and chloroform. Humidity present in the exhaled air is an important marker in determining the health of an individual. In this context, as exposure to PM severely affect lung, a sensor that can monitor the changes in humidity of the exhaled air was fabricated.5 A response time ~ 1 s was obtained while using electrospun fibers of polyaniline coated polyvinylidene fluoride/reduced graphene oxide), this was further improved to 0.3 s using polyaniline coated polypropylene cloth.
References
(1) Ghose, M. K. et al., Environ. Monit. Assess. 2007, 130 (1), 17–25.
(2) Kaufman Y. J. et., Nature. 2002, 419, 215-223.
(3) Cohen, A. J. et al., The Lancet 2017, 389 (10082), 1907–1918.
(4) Srikrishnarka, P. et al., ACS Sustain. Chem. Eng. 2020, 8 (21), 7762–7773.
(5) Iyengar, S. A.; Srikrishnarka, P. et al., ACS Appl. Electron. Mater. 2019, 1 (6), 951–960.