Advances in biopolymer-based membrane preparation and applications

Membrane technology has had a continue growth for the last 40 years. The forecast is that the membrane market will reach US$10.8 billion by the end of 2019. Unfortunately, it is also recognized as having a low sustainability with respect to membrane fabrication as this involves fossil-based polymers. It is well known that the environmental impact of plastic wastes represents a general global problem, and disposal technologies are limited. The growing environmental pollution has been the starting point for researching potential natural polymers able to substitute the conventional ones for membrane preparation. Biopolymers derived from animal (polylactic acid, polyhydroxyalcanoates, polybutylene succinate) or vegetable sources (cellulose-based polymers, alginate, polyisoprene, starch), as well as from bacterial fermentation products (chitin, chitosan, collagen, sericin), fascinated the research along with the growing worldwide trend towards sustainability. The use of biopolymers for the preparation of membranes, in fact, is very well documented in literature even if their application on a larger scale is still a challenge. This review addresses on the current (bio)plastic and membrane market with a look on the trend for the next years. Moreover, biopolymers used in membrane preparation are critically reviewed in terms of their synthesis, main properties and applications with particular emphasis on the main results of bio-based membranes during the last decades in the different fields of membrane technology including micro- and ultrafiltration, pervaporation, gas separation and medical applications.