Combined Effect of Microstructure, Surface Energy, and Adhesion Force on the Friction of PVA/Ferrite Spinel Nanocomposites

Abstract

Nanocomposite films based on spinel ferrite (Mg0.8Zn0.2Fe1.5Al0.5O4) in a PVA matrix were obtained. An increase in the spinel concentration to 10 wt.% caused an avalanche-like rise in roughness due to the formation of nanoparticle agglomerates. The lateral mode of atomic force microscopy (AFM) allowed us to trace the agglomeration dynamics. An unexpected result was that the composite with 6 wt.% of filler had a low friction coefficient in comparison with similar composites due to the successfully combined effects of low roughness and surface energy. The friction coefficient decreased to 0.07 when the friction coefficient of pure PVA was 0.72. A specially developed method for measuring nano-objects’ surface energy using AFM made it possible to explain the anomalous nature of the change in tribological characteristics.

Electroactive properties and piezo-tribo hybrid energy harvesting performances of PVDF-AlFeO3 composites: role of crystal symmetry and agglomeration of fillers

“…3(a) and (b), the average particle size of the AFRH and AFOR samples have been found to be ∼4 and 200 nm, respectively. Here, it is also to be mentioned that though both the particles show a tendency of agglomeration possibly due to their magnetic nature, 42 a significantly higher agglomeration tendency has been clearly observed for AFOR (from TEM images). The higher agglomeration tendency of the AFOR particle is attributed to the intra-particle diffusion and coalescence of small grains by the diffusion through the grain boundary due to the significantly higher value of the calcination temperature (1350 °C).…”

“…The high specific surface area of the AFRH sample compared to that of the AFOR particles confirms the smaller size of the former compared to that of the latter. 42 Moreover, the high agglomeration tendency of AFOR might cause a reduction in the specific surface area. The high surface area of AFRH suggests its high surface energy too, 42 which may make this material more reactive compared to AFOR (exhibiting low surface energy).…”

“…42 Moreover, the high agglomeration tendency of AFOR might cause a reduction in the specific surface area. The high surface area of AFRH suggests its high surface energy too, 42 which may make this material more reactive compared to AFOR (exhibiting low surface energy). Thus, the AFRH filler is expected to interact with the PVDF dipoles more efficiently than the AFOR filler, and hence, the electroactive and energy harvesting performance of the PVDF-AFRH system may be more appreciable than that of the PVDF-AFOR system.…”

Two-Dimensional Metal-Organic Framework Incorporated Highly Polar PVDF for Dielectric Energy Storage and Mechanical Energy Harvesting

“…Polymers, hydrogels, biomolecules, and their nanocomposites are perhaps the most widely studied materials class in present days, which show a wide variety of practical applications, including dielectric energy storage, electrode materials for supercapacitors, mechanical energy harvesting, separation membranes, and many others [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. In this regard, poly(vinylidene fluoride) (PVDF) is perhaps the most widely studied material in recent times due to its cost-effectiveness, easy synthesis procedure, and several other unique and suitable functional properties [ 9 , 10 ].…”

Tough, Injectable Calcium Phosphate Cement Based Composite Hydrogels to Promote Osteogenesis

“…CPC, which has good osteoconductive and biocompatible capacity, presents an advantageous alternative material. Fortunately, with the rapid development in nanotechnology, nanomaterials are easily characterized (such as using X-ray and neutron diffraction to detect structure) [ 16 , 17 , 18 ] and evaluated (surface morphology and surface energy determined by atomic force microscopy) [ 19 ]. Thus, nanomaterials have been widely applied in the ferrimagnetic and optical domains [ 20 , 21 ].…”