Research On Preparation And Properties Of Flexible Transparent Triboelectric Nanogenerator And Connection Of PAAm-SAlg Hydrogel/PDMS

Flexible transparent triboelectric nanogenerator(FT-TENG)is a new type of energy harvesting and self-powered sensor device,which has broad application prospects in the fields of wearable electronic products and energy skin.Using PDMS(SYLGARD 184)as the friction layer material and polyacrylamide-sodium alginate hydrogel as the electrode material can meet the requirements of flexibility and transparency of the device.In view of the problem that PDMS is difficult to directly connect with hydrogel at this stage,this thesis uses oxygen plasma and functional silane(TMSPMA)treating the surface of PDMS to achieve the connection,and prepares flexible transparent triboelectric nanogenerator..This thesis prepared PAAm-SAlg hydrogels and PDMS samples and analyzed their morphology and way of crosslinking reaction.The effects of process parameters on the electrical,mechanical and optical properties of hydrogels and PDMS were investigated.The connection strength between PDMS and hydrogel was tested by 90°peel test.The differences between two treatment methods were compared.The frictional charge density of the PDMS surface after friction was calculated by Kelvin probe force microscope(KPFM)combined with COMSOL simulation.The output characteristics of the flexible transparent triboelectric nanogenerator were studied.The PAAm-SAlg hydrogel was prepared by thermally induced cross-linking.The hydrogel obtained has the best tensile properties(0.038MPa,2200%)by holding at 60?for 35 min,and the lowest resistivity(1.5?·m)when 0.3 g/mL sodium sulfate is added.The comprehensive mechanical properties of PDMS prepared by holding at 80°C for 20min are optimal(0.6MPa,120%).In addition,the process parameters have little effect on the optical properties of the prepared PDMS and hydrogel,and the transmittance in the visible range is about 90%.Oxygen plasma cleaning and TMSPMA treatment of PDMS can achieve the connection with hydrogel,the maximum interfacial fracture toughness is22.5N/m and 33.5N/m.A layer of silanol(Si-OH)will be produced on the surface of PDMS after oxygen plasma cleaning method,and will completely fail after being placed in air environment(25?,RH=20%)for 10 hours.Therefore,PDMS is treated with a functional silane surface treatment method for its high degree of chemical reaction and low failure to achieve a long-term reliable connection with the hydrogel.The surface charge density of PDMS during the friction process was quantitatively characterized.The surface potential difference of PDMS is proportional to the surface friction charge density.After 50 times of friction,the electrostatic potential reaches a maximum of-40V,and the charge density can reach-162?C/m~2.The results were verified by COMSOL numerical simulation.The preparation of flexible transparent friction nano-generator(FT-TENG)was carried out.The output open circuit voltage gradually increased in the first 20 cycle periods,and finally stabilized at about 92V.And it fell less than 2%after 1000 work cycles and fell less than 10%after a week of standing,showing excellent job stability.