Physico-Chemical nanomaterials science 

Filtration and antibacterial properties of modified nonwovens
Avdeeva K.V.1, Shumskaya A.E.1, Dudchik N.V.2, Oleynik A.D. 2, Yarmolenko M.A.3 Mikhalko A.M. 3
1State Scientific Institution «Institute of Chemistry of New Materials of the NAS of Belarus» Fr. Skoriny st., 36, 220141,Minsk, Republic of Belarus
E-mail: shukova.yekaterina@yandex.by 
2Republican Unitary Enterprise "Scientific and Practical Center of Hygiene", 220012, Minsk, st. Academicheskaya, 8, Republic of Belarus 
3Laboratory «Physicochemistry and Technologies of Micro- and Nanosystems» Francisk Skorina Gomel State University, 104 Sovetskaya str., Gomel 246019, Belarus 

A crucial role in the development of a new class of antiviral materials can be played by vacuum plasma chemical and wet-chemistry methods for processing polymer surfaces, which affect on the morphology of polymers and provide a convenient way to regulate the chemical composition of surfaces.
The aim of our work is to develop new modifying layers that allow to increase filter parameters of nonwoven polymer based polypropylene materials ( brands "Akvaspan", "Spanbel", OJSC "SvetologorskKhimvolokno"), as well as to give them new antibacterial properties. 
To study the filtration characteristics of modified nonwoven materials, a laboratory stand was designed to evaluate the effectiveness of air filtration of aerosols with a particle size from 0.3 to 10 microns.
By using developed stand it was found, that the electron-beam deposition of micro - and nanocomposite layers based on polytetrafluoroethylene (PTFE) and copper can significantly increase the efficiency of air filtration from 78.75% to 96.66%. It is related to the appearance of a possible electrostatic interaction of the aerosol with the PTFE electret coating. The bacterial filtration efficiency value of 96.4-97.2 %. The bacterial filtration efficiency of materials without a modifying layer, as a rule, was less than 90 %. The wet-chemistry modification methods do not worsen the filtration characteristics of nonwovens materials, but close to the characteristics of the initial materials, which indicates the low efficiency of these modification methods. 
Thus, using plasma-chemical modification of the surface of nonwovens, a significant increase in the filtration properties of nonwovens was achieved, and the presence of micro - and nanoparticles of copper can significantly increase their antibacterial (antiviral) properties.