Investigation of structural and thermal characteristics of PVDF/ZnO nanocomposites Ajay Pal Indolia • M. S. Gaur Received: 25 August 2012 / Accepted: 19 November 2012 Ó Akade ´miai Kiado ´, Budapest, Hungary 2012 Abstract The structural and thermal behavior of PVDF/ ZnO nanocomposites have been investigated by employing scanning electron microscopy (SEM),TEM, DSC, powder X-ray diffraction (XRD), thermally stimulated discharge current (TSDC), and transient current techniques. SEM/TEM observation indicated the homogeneous dispersion of func- tionalized ZnO nanoparticles throughout PVDF matrix. DSC shows that the crystallinity is influenced by the presence of ZnO nanoparticles in the PVDF matrix because the filler acts as efficient nucleating agent to facilitate PVDF crystallization. DSC results indicated the enhancement of the glass transition temperature (T g ), melting temperature (T m ) and crystallization temperature (T c ) of nanocomposites compared to pristine PVDF. XRD shows that the full-width at half maximum decreases with increasing ZnO content, which is attributed to the improvement in crystallinity. The incorporation of ZnO nanoparticles influences the modification of polarization process in PVDF as observed by means of TSDC and transient current study. Keywords SEM  XRD  TSDC  Crystallization  Transient current  Nanocomposites Introduction Over the last decade, increasing demand of multifunctional materials has led to the conception of composites. In general, nanofillers with their nanometer size, high surface area, and the associated predominance of interfaces in the nanocomposites can function as a structural and morpho- logical director [1]. Recently, small amount of inorganic filler into organic polymer products has been extensively utilized in an attempt to enhance the electrical, mechanical, optical, and thermal properties [2–5]. Poly (vinylidene fluoride) (PVDF) is a semi-crystalline polymer with polar type voids. It has excellent physical and electrical properties such as high piezoelectric coefficient, good flexibility, biocompatibility, low acoustic, and mechanical impedance, and light mass, is especially unique for MEMS applications [6, 7]. Similarly, many properties of PVDF are improved by incorporation of nanofillers. Recently, it is reported [8] that inorganic nanoparticles can be used as an alternative means to control the interfacial properties. Although several studies explored the properties of the poly- mer nanocomposites as a function of nanosized fillers in PVDF [9–12], only few studies are focused in systems with ZnO embedded in PVDF. A lot of research work has been devoted to the crystal structure and crystallization behaviors of PVDF and its nanocomposites, but PVDF/ZnO nanocom- posites have not been undertaken. Thermal analysis method such as differential scanning calorimetry (DSC) was widely applied to characterize the thermal behaviors of polymers. In general, the nanofillers in polymer matrix affected the glass transition temperature (T g ) of polymers. ZnO into polymer matrix results in increase of thermal stability of polymer nanocomposites. Owing to characteristic nanoscopic dimen- sions of filler particles, several effects have been observed that can explain the changes in thermal properties. Thus, increas- ing the thermal stability of PVDF nanocomposites is an important feature for technical application of PVDF/ZnO nanocomposites [13, 14]. In this work, ZnO nanoparticles were used as filler in PVDF (i.e., piezo and pyro electric A. P. Indolia  M. S. Gaur (&) Department of Physics, Hindustan College of Science and Technology, Farah, Mathura 281122, Uttar Pradesh, India e-mail: mulayamgaur@rediffmail.com A. P. Indolia e-mail: pajay81@gmail.com 123 J Therm Anal Calorim DOI 10.1007/s10973-012-2834-0