Investigation Of Triboelectric Nanogenerator Based On Modified Polydimethylsiloxane Based

Polydimethylsiloxane(PDMS)is an excellent triboelectric material for its own flexibility,high transparency,good biocompatibility,and it has high shear resistance,corrosion resistance,excellent triboelectric properties,etc.These advantages make it widely used as the negative triboelectric material in triboelectric nanogenerator.PDMS-based triboelectric nanogenerators have the same excellent performance as PDMS materials,which is suitable to be used in mobile electronics.However,as a power-generating device,the energy output density per unit area or unit volume of a triboelectric nanogenerator is not large enough to supply the electronics,which severely limits the commercial application of triboelectric nanogenerators.At present,there are few research on the optimization and modification of triboelectric materials.Most of the optimization methods are complex and costly,only suitable for some specific triboelectric material or specific device structure.Therefore,it is necessary to study the modification and optimization of triboelectric materials.In this work,three methods are used to modify the triboelectric materials,and the three optimization methods are then integrated to improve the performance of triboelectric nanogenerators in the same time.The surface of the triboelectric material was roughened by simple sandpaper template.Through the metallurgical microscope,the scanning electron microscope and the atomic force microscope,the results show that the morphology size of negative triboelectric material is close to 2 ?m while prepared by the sandpaper template in the grit of 10000.As for the electrical performance,the open-circuit voltage and the transferred charge quantity of the device without the template were 35 V and 15 nC,respectively.After only PDMS roughened with sandpaper in size of 10000,the voltage and the transferred charge increased to 48 V and 19 nC,respectively after spin coating of PDMS with 10000 mesh sand,respectively,which increased by 37% and 26%;With only copper roughened with sandpaper in size of 10000,the open-circuit voltage and transferred charge quantity were 76 V and 30 nC,respectively,increased by 117% and 100%;With both PDMS and copper roughened,the open-circuit voltage and transferred charge quantity were 200 V and 76 nC,respectively,increased by 471% and 406%.Whether it is single-sided roughening treatment or double-sided roughening treatment,the improvement of the performance is obvious.Especially for the device with double-side roughening,when the two friction layer materials were patterned by the sandpaper template with the same grit size,the well-matched structure will greatly increase the actual contact area during the rubbing process and greatly increase the device output performance.The PDMS was doped with polytetrafluoroethylene for chemically modification so that the higher electronegativity group was introduced into triboelectric material,thereby friction pair had larger triboelectric difference and the TENG device got an increasing transferred charge quantity per unit area.X-ray diffraction analysis and X-ray photoelectron spectroscopy showed that the F atom with stronger electronegativity was introduced into the PDMS molecular chain.When introducing 10% at the mass ratio,the open circuit voltage and transferred charge got the largest valve,180 V and 82 nC,respectively,compared to the non-doped device of 56 V and 27 nC,respectively,increased by 220% and 203%.The PDMS was filled with conductive carbon black and nano-copper particles to improve the film capacitance.While 10 g PDMS filled with 0.2 g carbon black,the open circuit voltage and transferred charge quantity reached the largest,about 155 V and 62 nC,respectively;While 10 g PDMS filled with 0.3 g nano-copper particles,the open circuit voltage and transferred charge quantity reached the largest,140 V and 60 nC,respectively;The filling effect of two particles is quite.The micro-capacitors were produced while filling the conductive particles into PDMS film,equivalent to reducing the effective thickness of PDMS film,increasing the film capacitance and the device performance.Combining the surface roughening,chemical treatment and conductive particle filling these three optimization methods,the open circuit voltage,transferred charge and current of the device reached 350 V,6.5 m A and 130 nC,respectively,which make the TENG device achieve a great application prospect.