Novel nanocomposite membranes from cellulose acetate and clay-silica nanowires Mihai Cosmin Corobea a , Oana Muhulet b , Florin Miculescu c , Iulian Vaile Antoniac c , Zina Vuluga a , Dorel Florea a , Dumitru Mircea Vuluga d , Maria Butnaru e , Daniela Ivanov f , Stefan Ioan Voicu b * and Vijay Kumar Thakur g * In this study, a new class of heterogeneous membranes based on cellulose acetate (CA) polymer and a complex filler clay-silica nanowires (SiO 2 NWs) was investigated for potential biomedical applications. SiO 2 NWs were synthesized using natural clay through a facile sol–gel method and were dispersed in the polymer solution by sonication in the 1.25, 2.5, and 5% weight ratio to the CA acetate polymer. Membranes were subsequently prepared via phase in- version by precipitation of the CA polymer in water. The pristine CA membrane and SiO 2 NWs based nanocomposites membranes were characterized using different characterization techniques. The presence of the SiO 2 NWs in the CA membrane was found to significantly enhance the protein retention, water wettability and thermal as well as me- chanical properties in comparison to the pristine CA membrane. Water flows studies at different temperatures and the retention of bovine serum albumin have been studied and the nanocomposite membranes were found to exhibit superior performances compared with the pristine CA membranes. SiO 2 NWs-CA membranes showed a much higher stability to the water temperature change during separation than CA membranes. Morphological changes clearly revealed that the composite membrane were much more compact than the pristine CA membranes. The rab- bit dermal fibroblasts cell viability in cultures after 72 hr of incubation was found to be greater than 80%. These newly synthesized composite membranes exhibit a high potential to be used for various medical applications be- cause of their non-cytotoxic characteristics. Copyright © 2016 John Wiley & Sons, Ltd. Keywords: nanocomposite membrane; cellulose acetate; silica nanowires; cytotoxycity; characterization INTRODUCTION The interesting combination of polymer’s properties such as low density and weight, flexibility, low cost, chemical resistance and ease of handling and processing have made them a materials of choice. [1–4] Indeed, polymers based materials are widely being used for a number of applications and during the last few years, significant amount of study has been devoted to improve the existing properties of polymers. [5–8] The use of nanomaterials in combination polymers offers a number of applications in the biomedicine (as artificial kidney, [9] liver, [10] pancreas, [11] lungs, [12] food, [13] ) and drug delivery fields. [14–17] Among various such functional materials widely being used today in both industrial and laboratory practice, composite membranes have evolved as new promising materials because they offer a large applica- tion spectrum in the active participation in the separation pro- cess. In membrane based materials, the use of fillers offers two main advantages (i) increases the mechanical strength and (ii) improves the membrane separation properties by changing the porosity or through polymers significantly enhances their effi- cacy for different applications. [18–20] As an example of the haemodialysis membranes based on polysulfide and carbon * Correspondence to: Stefan Ioan Voicu, University Polytechnic of Bucharest, Faculty of Applied Chemistry and Materials Science, Str. Gheorghe Polis 1-7, Bucharest, 011061, Romania. E-mail: svoicu@gmail.com ** Correspondence to: Vijay Kumar Thakur, Washington State University, School of Mechanical and Materials Engineering, Pullman, WA, United States. E-mail: vijayisu@hotmail.com a M. C. Corobea, Z. Vuluga, D. Florea Polymer composites and nanocomposites team, Polymer Department, R&D National Institute for Chemistry and Petro chemistry – ICECHIM Bucharest, 6 Spy. Independence 202, district 6, Bucharest, 060021, Romania b O. Muhulet, S. I. Voicu Faculty of Applied Chemistry and Materials Science, University Polytechnic of Buchares, Str. Gheorghe Polis 1-7, Bucharest, 011061, Romania c F. Miculescu, I. V. Antoniac Faculty of Materials Science, University Polytechnic of Bucharest, Splaiul Independentei 313, Bucharest, Romania d D. M. Vuluga Center for Organic Chemistry “C.D. Nenitescu” of Romanian Academy, 202B Splaiul Independentei, 060023, Bucharest, Romania e M. Butnaru Faculty of Medical Bioengineering, “Gr.T.Popa” University of Medicine and Pharmacy, 16 University Street, 700115, Iasi, Romania f D. Ivanov “Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, 700487, Iasi, Romania g V. K. Thakur School of Mechanical and Materials Engineering, Washington State University, Pullman WA, United States Research article Received: 10 March 2016, Revised: 12 April 2016, Accepted: 2 May 2016, Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/pat.3835 Polym. Adv. Technol. (2016) Copyright © 2016 John Wiley & Sons, Ltd.