Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose-Acetate/Silica/Titania and Cellulose-Acetate/Titania Membranes

Inês Peixoto; Mónica Faria; M Clara Gonçalves

doi:10.3390/membranes10090195

Synthesis and Characterization of Novel Integral Asymmetric Monophasic Cellulose-Acetate/Silica/Titania and Cellulose-Acetate/Titania Membranes

Membranes (Basel). 2020 Aug 20;10(9):195. doi: 10.3390/membranes10090195.

Authors

Inês Peixoto¹, Mónica Faria², M Clara Gonçalves³

Affiliations

¹ Department of Biotechnology, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
² CeFEMA and Department of Chemical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
³ CQE and Department of Chemical Engineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.

Abstract

Two series of novel integral asymmetric monophasic hybrid membranes, cellulose acetate/silica/titania (CA/SiO₂/TiO₂-series 1) and cellulose acetate/titania (CA/TiO₂-series 2), were developed by the coupling of sol-gel technology and a modified version of the phase inversion technique. SEM micrographs confirmed the integral asymmetric structure of all membranes. ATR-FTIR and ICP-OES results showed that, for the membranes in series 1, TiO₂ is covalently bound to SiO_2, which, in turn, is covalently bound to CA, while for the membranes in series 2, TiO₂ is directly and covalently bound to the CA matrix. Permeation experiments revealed that the permeation performance of the membranes in series 1 is unaffected by the introduction of TiO₂. In contrast, the introduction of TiO₂ in the series 2 membranes increased the hydraulic permeability by a factor of at least 2 when compared to the pristine CA membrane and that incremental additions of TiO₂ further increased the Lp.

Keywords: cellulose acetate/silica/titania membranes; cellulose acetate/titania membranes; monophasic hybrid membrane; nanocomposite membrane; phase inversion; sol-gel; ultrafiltration.