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Changes in free volume and gas permeation properties of poly(vinyl alcohol) nanocomposite membranes modified using cage‐structured polyhedral oligomeric silsesquioxane
Author(s) -
Swapna Valiya Parambath,
Kaliyathan Abitha Vayyaprontavida,
Abhisha Vakkoottil Sivadasan,
Maria Hanna Joseph,
Nambissan Padinharu Madathil Gopalakrishnan,
Thomas Sabu,
Stephen Ranimol
Publication year - 2021
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49953
Subject(s) - silsesquioxane , vinyl alcohol , membrane , materials science , polymer chemistry , permeation , ethylene glycol , polyethylene glycol , polymer , nanocomposite , chemical engineering , polyvinyl alcohol , chemistry , composite material , biochemistry , engineering
The present work reports the effect of various organically functionalized polyhedral oligomeric silsesquioxane (POSS) particles on the gas transport properties (N 2 , O 2 , and CO 2 molecules) in poly(vinyl alcohol) (PVA) membranes . The incorporation of polyethylene glycol‐POSS (PEG‐POSS), octa‐tetramethylammonium‐POSS (Octa‐TMA‐POSS) and m‐POSS (Octa‐TMA‐POSS molecule was modified using cetyltrimethyl ammonium bromide) led to the enhancement in CO 2 separation performance of PVA, among which, PEG‐POSS exhibited highest CO 2 separation due to the dipole‐quadrupolar interaction of CO 2 with ethylene oxide group in POSS. Octa‐TMA‐POSS and m‐POSS reduced the O 2 and N 2 permeability of the PVA membrane due to the reduction in the number of permeating pathways as compared to pure PVA. Free volume of the membranes was evaluated by positron annihilation lifetime spectroscopic (PALS ) and coincidence Doppler broadening measurements . PALS confirms the increase in polymer free volume in PVA/POSS system due to the presence of rigid and spherical POSS molecule, which could enter in the polymer chain and provide viable pathway for molecular transport. Maxwel–Wagner–Sillar and Higuchi models were applied for the theoretical prediction of permeability of the fabricated membranes.