Comparison of the effects of graphene and nanoclay nanosheets on crystalline structure of polyvinylidene fluoride

Applied Nanomaterials and Smart Polymers

دوره 1، شماره 2، آبان 2023، صفحه 24-35   

نوع مقاله: Original Article

نویسنده

Ali Akbar Yousefi^*

Department of Plastics, Iran Polymer and Petrochemical Institute

چکیده

 An extensive review of the literature showed that both graphene and Cloisite 30B nanosheets are widely
employed to modify the crystalline structure and piezoelectic properties of polyvinylidene fluoride (PVDF).
Due to the similarity in the geometry of these nanoparticles a comparative study is reported to find the stems
of difference in their effects on crystalline structure of PVDF. Scanning electron microscopy (SEM) of these
composites showed that large and wide graphene particles are dispersed in PVDF matrix whereas their
thickness is well below 100 nanometers. Meanwhile, a careful inspection of SEM micrographs of Cloisite 30B
loaded composites revealed existence of smaller particles with almost the same particles thicknesses. Both
techniques of Fourier transform infrared (FT-IR) spectroscopy and wide angle X-ray diffraction (WXRD)
witnessed changes in the crystalline structure of PVDF. The overall finding was that Cloisite 30B improves
the polar beta phase of PVDF crystals, whereas a revers effect was found in the presence of graphene
nanosheets. These observations were accounted for by differences in surface geometry and surface free energy
(surface tension and interfacial tension). Based on the data available for surface properties of these two
nanosheets it was found that surface properties of Cloisite 30B is very close to those of PVDF, whereas the
surface properties of graphene are far from those of PVDF. Also a lower interfacial tension was found to be
active in PVDF-Cloisite 30B system compared to that operative in PVDF-graphene system. An intimate
interface along with proper surface texture led to higher content of PVDF’s beta crystals in case of Cloisite
30B nanocomposite. 

کلیدواژه‌ها

PVDF؛ Cloisite 30B؛ graphene؛ surface free energy؛ morphology