Starch/PVA hydrogels for oil/water separation

• Published in: Environmental science and pollution research international Vol. 26; no. 31; pp. 32013 - 32028
• Main Authors: Thakur, Kirti, Rajhans, Aditya, Kandasubramanian, Balasubramanian
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2019; Springer Nature B.V
• Subjects: absorbents; Adsorption; Aquatic Pollution; Arid regions; Atmospheric Protection/Air Quality Control/Air Pollution; Biodegradability; Biodegradation; brittleness; Contact angle; Crosslinking; Earth and Environmental Science; Ecotoxicology; Emulsions; Environment; Environmental Chemistry; Environmental Health; Environmental science; Glutaraldehyde; Hydrogels; Hydrogels - chemistry; Hygiene; irrigation; Kinetics; mixing; Oil; oils; plasticity; Polymers; Polymers - chemistry; Porosity; Product development; Research Article; Semi arid areas; semiarid zones; Starch; Starch - chemistry; swelling (materials); Waste Water Technology; Water - chemistry; Water absorption; Water Management; Water Pollution Control; water uptake; Biodegradation; Polymer blend; Degradation mechanism; Janus materials; Superabsorbent
• ISSN: 0944-1344; 1614-7499; 1614-7499
• DOI: 10.1007/s11356-019-06327-z

PVA polymers have been well-known as water-absorbing materials but their brittle nature hinders their applicability. In this study, we enhanced the strength of hydrogel and its water-absorbing capabilities by glutaraldehyde-assisted crosslinking of starch with PVA and blending BMIM-BF 4 to enhance the plasticity and generate porosity within the hydrogel multiplying the swelling capacity up to 300% and understand the kinetics and mechanism of water absorption based on the structure of the hydrogel. The ability of starch/PVA hydrogel to selectively adsorb water from oil–water emulsions was determined by establishing the underwater oleophobic nature (oil contact angle ~ 153.6°), subjecting the hydrogel to oil–water emulsion to determine the water absorbed. The hydrogels' biodegradable nature was tested by an efficient in-house biotic system and mechanisms for biodegradation have been discussed. The biodegradability (~ 90%) was determined for 50% starch in PVA sample in 28 days. These properties observed in the hydrogels will find applications in irrigating arid and semi-arid areas and also in developing superabsorbent hydrogels for hygiene-related product development etc. which can be biodegraded in an economic way. Graphical abstract