ORIGINAL PAPER Transparent and fluorescent thin films of polysilane–SiQD nanocomposite: cellulose acetate Liviu Sacarescu . Mihaela Simionescu . Gabriela Sacarescu . Sergiu Coseri Received: 17 June 2016 / Accepted: 27 August 2016 / Published online: 1 September 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract Fluorescent and highly transparent free standing thin films have been prepared using polysi- lane–silicon quantum dots nanocomposite (PSiQD) dispersed within cellulose triacetate (CA). Polysilane acts like a carrier that transports the silicon quantum dots (SiQDs) within the CA matrix. Extremely low, subcatalytic amounts of PSiQD are enough to transfer to CA the optical properties of both polysilane and SiQDs. Thin films obtained by solvent casting are mechanically resistant, highly flexible and show the characteristic high intensity fluorescent emission due to SiQDs. Also, the nanocomposite is UV photosen- sitive and could be easily converted to a hydrophilic material, compatible with the common paper. The PSiQD carrier is obtained in situ by microwave assisted coupling of chlorosilanes in heterogeneous reaction conditions. ATR-FTIR analysis was used to investigate the chemical structure within the bulk material. The presence of SiQDs and their content within the CA nanocomposite were proved by XPS. These results were further sustained by TEM and SAXS analysis. The wetting properties of the com- posite were probed before and after UV exposure by contact angle measurements. Thin films of such a nanocomposite material are designed for special opto- electronic applications that require processing by UV patterning and control of surface wetting properties. Keywords Composite materials Á Cellulose Á Quantum dots Á Optical properties Introduction Cellulose, among the most versatile and widely prevalent biopolymers in nature, has been used for millennia for human elemental needs, e.g. as a cheap building material, for fabrication of the clothing and as energy source, but founded today, through its deriva- tives, new and exotic applications in food industry, medicine, cosmetic, flexible display panels, electronic devices and many others (Andersson et al. 2002; Barr et al. 2011; Hu et al. 2010; Kim and Steckl 2010; Martins et al. 2008; Mazzeo et al. 2012; Siegel et al. 2010; Tobjork and Osterbacka 2011). It is known that a possible approach to create materials with funda- mentally new properties is by synergistic combination of effects generated by different components at nano size level (Kamigaito 1991). This method is also applicable for cellulose-based nanocomposites and has two generally accepted variants. Thus, there is the in situ process where the nanoparticles are produced by chemical interactions between cellulose derivatives and salts or dedicated organic compounds (Breitwieser L. Sacarescu (&) Á M. Simionescu Á G. Sacarescu Á S. Coseri Petru Poni Institute of Macromolecular Chemistry – Romanian Academy, Grigore Ghica Voda 41A, 700487 Iasi, Romania e-mail: livius@icmpp.ro 123 Cellulose (2016) 23:3847–3860 DOI 10.1007/s10570-016-1058-z