Development of bacterial cellulose and poly(vinylidene fluoride) binary blend system: Structure and properties K. O-Rak a , E. Phakdeepataraphan a , N. Bunnak a , S. Ummartyotin b,⇑ , M. Sain b,c , H. Manuspiya a,⇑ a The Petroleum and Petrochemical College, Centre of Excellence on Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330, Thailand b Centre for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, 33 Willcocks Street, Toronto M5S 3B3, Canada c King Abdulaziz University, Jeddah, Saudi Arabia highlights  Bacterial cellulose and poly (vinylidene fluoride) binary blend system was developed.  Bio-blend material was designed as flexible substrate with additional feature of touch screen characteristic.  There is significant improvement on dielectric properties superior to neat bacterial cellulose. article info Article history: Received 21 May 2013 Received in revised form 4 October 2013 Accepted 10 October 2013 Available online 23 October 2013 Keywords: Bacterial cellulose (BC) Poly(vinylidene fluoride) (PVDF) Blend materials Dielectric properties abstract Bacterial cellulose (BC)/Poly(vinylidene fluoride) (PVDF) was successfully prepared by a binary blend sys- tem. Less than 50 wt% of BC was completely incorporated into the PVDF matrix. PVDF penetrated the por- ous nano-fibril network of the BC structure. The thermal properties of this blend material were stable up to 250 °C. Significant enhancement of the dielectric properties was found; this binary blend provided high polarization and dielectric properties. Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction In recent years, concern over the shortage of petrochemical materials and the ever growing issue of global waste, along with rising oil prices and the pending exhaustion of landfills, has created a demand for research and development of eco-friendly materials. Numerous types of bio-based materials including cellulose [1,2], chitin–chitosan [3,4], polylactic acid [5,6], as well as soy protein [7,8] have been extensively used for the improvement of engineer- ing properties, in order to replace petrochemical materials. Among the various types of bio-based materials, cellulose [9–11], one of the most abundant biopolymers, has received considerable atten- tion because of its potential applications in this environmentally friendly era. Recently, there has been a great deal of research interest in utilizing cellulose for various applications; one example is composite manufacturing because it provides remarkable reinforcing capabilities, excellent mechanical properties, as well as environmental benefits. Significant research on cellulose-based composites has brought about many engineering applications such as automotive parts [12,13], adhesives [14], textiles [15], infra- structures [16], medical devices [17] as well as electronic compo- nents [18]. In recent years, our research group has developed a cellulose-based composite for organic light emitting diode substrates [19]. This composite is flexible and transparent when produced by the roll-to-roll process [20]. Moreover, in order to reach the minimum requirement as a flexible electronic substrate, this cellulose-based composite has been further developed to im- prove water absorption ability [21] and surface smoothness [22]. The epitaxial growth of the Si–O film nano-layer and the use of fer- rofluid solution have been employed to modify the cellulose-based composite. The use of thermoplastic polymer substrates has also satisfied on fundamental properties in terms of flexibility. The cost and ease of processing have madecellulose-based composites a good candidate for mass production. Numerous thermoplastic polymer substrates have been developed. Polycarbonate [23] and 1385-8947/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cej.2013.10.032 ⇑ Corresponding authors. Tel.: +66 2 2184125; fax: +66 2 218 4145 (H. Manuspiya), tel.: +1 416 826 4866; fax: +1 416 978 3834 (S. Ummartyotin). E-mail addresses: sarute.ummartyotin@gmail.com (S. Ummartyotin), hathai- karn.m@chula.ac.th (H. Manuspiya). Chemical Engineering Journal 237 (2014) 396–402 Contents lists available at ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej