Constructing Implantable Membrane Energy Storage Devices Via Functional Polymer Brushes Modified Gold Nanoparticles

With the fast development of the modern medicine,the implantable energy storage devices as an important kind of power supply system for clinical application for implantable medical devices had become the new hot topic in energy field.Flexible supercapacitors is a key implantable energy storage device because it represents high power density,fast charging and discharging,and long-term cycle stability,and most importantly,it can provide constant energy output even under the mechanic deformation.The implantable energy storage devices,for example,supercapacitors,which be used as power supply system for clinical application for implantable medical devices,should have the following features:(1)good biocompatibility involving homocompatibility and cytocompatibility;(2)flexible,thin and good mechanical property to guarantee keeping the original shape for working when encounter complex deformation conditions like stretching,folding,and bending;(3)supplying enough energy with good cycle stability.Based on this,this thesis uses polyethersulfone as the substrate,aims to obtain flexible supercapacitors devices,starts with preparing and modification of nanoparticles,adopts membrane fabrication by liquid to liquid phase separation,and studying the migration and self-assemble of the nanoparticles during the fast solvents exchanging,to design and prepare the hybrid membrane,membrane electrode,and membrane energy storage devices,and finally fabricates the sandwich structure and all-in-one implantable supercapacitors.The basic research context and the main conclusions are summarized as follows:(i)A series of functional polymer brushes grafted gold nanoparticles are designed and synthesized,which include hydrophilic group grafted gold nanoparticles(Au NP@SC)and hydrophobic group grafted gold nanoparticles(Au NP@C6),hydrophilic polymer grafted gold nanoparticles with core-shell structure(Au NP@PMEO₂MA,Au NP@PAA,Au NP@PMAA,and Au NP@PAm),hydrophobic polymer grafted gold nanoparticles with core-shell structure(Au NP@PS),hydrophilic polymer and hydrophobic polymer brushes co-grafted gold nanoparticles with core-shell structure(Au NP@PS&PMEO₂MA),hydrophiphilic co-polymer brushes grafted gold nanoparticles with core-shell structure(Au NP@PS-b-PMEO₂MA and Au NP@PAm-g-PMAA),hydrophilic polymer and hydrophobic polymer brushes co-grafted gold nanoparticles with Janus structure(Au NP@C6||PMEO₂MA),and crosslinked gold nanoparticles(Au NP@hexanedithiol).Surface modified gold nanoparticles are characterized and analysized by TEM,XPS,FTIR,UV,NMR,AFM,and DLS.(ii)These functional polymer grafted nanoparticles are used as modification additives to fabricate a series of surface hydrophilic,surface hydrophobic,surface hydrophiphlic,and surface crosslinked polyethersulfone membranes.The modified membranes are characterized by SEM,FTIR,XPS,mapping,and so on.Some basic physical properties are investigated in detail,and the migration and self-assemble mechanism of polymer brush grafted nanoparticles are proposed.The data and results show that hydrophiphilic and Janus nanoparticles should be the most two efficient polymer brushes for surface modification of polyethersulfone,and the Janus structure is better than the other one.(iii)The biomass carbon derived from red willow exhibits high specific surface area of 1,758 m²/g,rational pore distribution of 0.15-1.15 nm,and the interworking structure of 100-300 nm;and high specific capacity of 453 F/g at the current density of 0.5 A/g in 2 M KOH.The biomass is blended into porous polyethersulfone membrane to prepare membrane electrode membrane with good flexibility and high electrochemical performance.The electrode membrane has area capacity of 375m F/cm²at 0.5 m A/cm²in the simulated body fluid.The sandwich energy storage device assembled with the electrode membrane and PVA has area capacity of 47.5m F/cm²at 0.5 m A/cm²in the simulated body fluid.As the key product of this project,the all-in-one device is constructed without inter-facial problems.The thickness of the all-in-one device could be controlled by simply changing the fabrication condition.The all-in-one device has area capacity of 3.6 m F/cm²at 0.1 m A/cm²in the simulated body fluid.This value should be valuable for the implantable energy storage devices.(iv)The anti-protein adsorption experiment shows that introducing biomass carbon does not affect the hydrophilic property of the membrane,however,does increase the water permeation,which is similar to the pristine polyethersulfone,revealing good anti-protein adsorption property.The experiment of platelet adhesion shows that the amounts of platelet adhered on the all-in-one device and pristine polyethersulfone are almost the same;however,the difference is the shape of the adhered platelet,that in the pristine polyethersulfone is aggregated and accumulated,while that in the all-in-one membrane device remains the ball shape.APTT experiment shows that there are good anti-coagulant performance not only for both of membrane electrode membrane and device,but also both of the pristine and modified polyethersulfone.Complement activation together with anti-protein pollution,platelet adhesion,and APTT reveal the good blood compatibility of the membrane energy storage device.The MTT and LO2 cells experiment exhibits that the fabricated all-in-one has good cytocompatibility.More important,the all-in-one membrane energy storage device has the good mechanical stability,good electrochemcial cycle and stability.