Formation of Water-Free Cavity in the Process of Nafion Swelling in a Cell of Limited Volume; Effect of Polymer Fibers Unwinding

Polymers

BarryW. Ninham¹  PolinaN. Bolotskova²  ValeriyA. Kozlov²  MariyaS. Kiryanova²  RomanS. Safronenkov²  NikolaiF. Bunkin²  ElenaV. Uspenskaya³  Yulchi Juraev⁴  SergeyV. Gudkov⁵  AlexeyV. Shkirin⁵ 

[1] Department of Applied Mathematics, The Australian National University, Acton, ACT 2601, Australia;Department of Fundamental Sciences, Bauman Moscow State Technical University, 2-nd Baumanskaya str. 5, 105005 Moscow, Russia;Department of Pharmaceutical and Toxicological Chemistry, RUDN University, Miklukho-Maklaya str. 6, 117198 Moscow, Russia;Department of Theoretical Physics and Quantum Electronics, Samarkand State University, University blv. 15, Samarkand City 140104, Uzbekistan;Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilova str. 38, 119991 Moscow, Russia;

关键词: swelling of polymers;    wetting angle;    Nafion;    Fourier transform IR spectroscopy;    deuterium-depleted water;   

DOI  :  10.3390/polym12122888

来源: DOAJ

【 摘 要 】

When Nafion swells in water, colloidal particles are repelled from the polymer surface; this effect is called the formation exclusion zone (EZ), and the EZ size amounts to several hundred microns. However, still no one has investigated the EZ formation in a cell whose dimension is close to the EZ size. It was also shown that, upon swelling in water, Nafion fibers “unwind” into the water bulk. In the case of a cell of limited volume, unwound fibers abut against the cell windows, and water is completely pushed out from the region between the polymer and the cell window, resulting in a cavity appearance. The temporal dynamics of the collapse of this cavity was studied depending on the cell size. It is shown that the cavity formation occurs due to long-range forces between polymer strands. It turned out that this scenario depends on the isotopic composition of the water, ionic additives and water pretreatment. The role of nanobubbles in the formation and collapse of the cavity were analyzed. The results obtained allowed us to conclude that the EZ formation is precisely due to the unwinding of polymer fibers into the liquid bulk.

【 授权许可】

Unknown