Polymer-inorganic hybrid membranes preparation

Wu, C., Wu, Y., Xu, T., Fu, Y. (2008) Novel anion-exchange organic-inorganic hybrid membranes prepared through sol-gel reaction and UV/thermal curing. Journal of Applied Polymer Science, 107, 1865-1871. 

The preparation of defect-free zeolite layers on a large scale is extremely difficult and it seems doubtful that this will ever be achieved at a competitive price. However, the combination of the superior gas selectivities of molecular sieves with the processibility of polymeric membranes has attracted many researchers. The hybrid membranes consisting of inorganic molecular sieves and polymers are often referred to as mixed-matrix membranes. The term mixed-matrix membrane has been introduced by Kulprathipanja et al. [309], who performed pioneering work in the field of polymer/zeolite hybrid membranes. Kulprathipanja showed that the CO2/H2 selectivity of cellulose acetate could be reversed by addition of silicalite. The siHcaHte-CA membrane had a CO2/H2 selectivity of 5.1, whereas the pure CA membrane exhibited a selectivity of 0.77. 

Zhua T, Lina Y, Luoa Y et al. 2012. Preparation and characterization of TiOj-regenerated cellulose inorganic-polymer hybrid membranes for dehydration of caprolactam. Carbohydr. Polym. 87 901-909. 

The choice of the polymer and fillers is very important to develop advanced hybrid membranes for a particular separation process, but the major challenge is to prepare a defect-free interface between the organic and inorganic phase. Indeed, the interfacial morphology plays a crucial role for the determination of the transport properties of the hybrid matrix, and a departure from ideal conditions can lead to a severe worsening of the separation performance. In Fig. 7.6 the possible conditions at the interface are shown. 

Fu et al. [124] prepared a series of novel covalent organic-inorganic hybrid proton-conductive membranes, each with a semi-interpenetrating polymer network (semi-IPN), for DMFC applications through polymer reactions and sol-gel method. A sulfonation reaction was produced as last step. The developed copolymer chains interpenetrated into the PVC matrix to form the semi-IPN structure, and the inorganic silica was covalently bound to the copolymers. 

Fu, R.Q., Woo, J.J., Seo, S.J., Lee, J.S., and Moon, S.H. (2008) Covalent organic/ inorganic hybrid proton-conductive membrane with semi-interpenetrating polymer network preparation and characterizations. /. Power Sources, 179, 458 466. 

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