Study On Preparation And Properties Of Surface Modified Carbon Black,Carbon Nanotube And Graphene

Due to the excellent performances and broad application prospects of carbon nanomaterials,their surface functionalization became a hot topic in the field.In this thesis,the surface of carbon black was modified by polyelectrolyte and its pH responsive property,self-assembly behaviors and gas sensing performances were investigated.Carbon nanotube and graphene were modified with?-CD and the electrochemical responsive properties of?-CD modified graphene and gas sensing properties of P-CD modified carbon nanotube were investigated.By introducing non-covalent modification,polymer brush grafting and dendritic,hyperbranched PAMAM grafting,functionalized graphene composites were prepared and their applications were also investigated.?1?Four kinds of carboxylated carbon blacks?CB-COOH?were prepared by nitric acid oxidation and effect of oxidation time on the degree of carboxylation was investigated.Then,three kinds of brominated carbon blacks?CB-Br?with different bromine containing group contents were prepared by acylating chlorination,hydroxylation and bromination reaction.CB-Br was then transformed to obtain RAFT agent functionalized carbon black?CB-SC?S?Ph?.Using SI-RAFT polymerization,five kinds of polyacrylic acid grafted carbon black?CB-g-PAA?with different PAA contents were synthesized and the influence of polymerization time and the amount of acrylic acid monomer were investigated.It was observed that size of CB-g-PAA nanoparticles was effected by change in pH and these nanoparticles aggregated or dispersed upon pH variations.The electrostatic interaction induced self-assembly behaviors of CB-g-PAA nanoparticles with CTAB or Star-(PDMEAIEMA₂₆)₆ were studied to obtain micron-scale honeycomb structures and the influence of different CTAB or Star-(PDMEAIEMA₂₆)₆ contents were investigated.Gas sensing performances of the CB-g-PAA based devices showed their resistance response to ethanol and n-butanol,in which it has a good tolerance for ethanol.?2?Three kinds of graphene-cyclodextrin?RGO-CD?complexes with different?-CD contents were prepared in situ by the reduction of hydrazine hydrate.RGO-CD complexes were characterized using TGA,Raman spectroscopy,TEM and AFM.CV was used to investigate the host-guest interaction of RGO-CD with PAMAM-Fc in DMF or DMSO.RGO-CD can get PAMAM-Fc enriched and electrochemically recognized.The enrichment effect and the sensitivity of electrochemical recognition were also increased with increasing ?-CD contents.Then,the inclusion behaviors of the cyclodextrin cavity in RGO-CD to ferrocene end groups of PAMAM-Fc using DMF and DMSO as solvents were discussed,and its impact on the electrochemical behaviorm was investigated.MWNT-COOHs was prepared by nitric acid oxidation,and three kinds of MWNT-CDs with different ?-CD contents were prepared by covalent modification.Their composition and structure were characterized by FT-IR and TGA.The morphology of MWNT-CDs was characterized by TEM and it was found that MWNT-CDs can be well dispersed.Finally,the MWNT-CD based gas sensing electrodes were prepared to test its gas sensing for THF,CHCl₃ or C₆H₆,and was found to have good response performances and sensitivity.?3?PAMAM dendrimers of first and second generations were synthesized,and dendritic PAMAM structures were characterized by NMR and FT-IR spectroscopy.Then,four kinds of PAMAM dendrimer modified graphene?GO-PAMAM-DEN?with different dendrimer generations or contents were prepared by "grafting to" method.Hyperbranched PAMAM modified graphene?GO-PAMAM-HP?was also synthesized by "grafting from" method.SEM,TEM and AFM were used to characterize the morphology of dendrimer or hyperbranched PAMAM modified graphene.Then,gold nanoparticles were synthesized in situ with dendrimer or hyperbranched PAMAM modified graphene as the template,respectively.Two kinds of gold nanoparticles loaded dendrimer modified graphene?Au@RGO-PAMAM-DEN?with different dendrimer generations and one kind of gold nanoparticles loaded hyperbranched PAMAM modified graphene?Au@RGO-PAMAM-HP?were obtained and characterizd by TEM and HR-TEM,SEM and AFM.Their compositions were determined using UV-vis absorption spectra.The catalytic activities of Au@RGO-PAMAM were evaluated by sodium borohydride reduction of 4-nitrophenol as a model reaction.It was found that the Au@RGO-PAMAM had high catalytic activity for this reaction.?4?Three kinds of low molecular weight chitosan modified graphene?RGO-chitosan?with chitosan of different molecular weights were synthesized and their structure and compositions were characterized by UV-vis,XRD,FT-IR,TGA,Raman,XPS and Z potential.The morphology of RGO-chitosan were studied by TEM and SEM.The adsorption behaviors of hexavalent chromium?Cr?VI??ions in aqueous solution by RGO-chitosan were tested and the effects of different initial concentrations of Cr?VI?on the adsorption properties were investigated.It was found that RGO-chitosan had good adsorption performances for Cr?VI?.?5?Three kinds of GO-Brs with different brominated ATRP initiator contents were prepared and PDMAEMA with different contents were grafted to the graphene surface by "grafting from"method.Then,GO-PDMAEMAs were converted to positively charged GO-PAmMeIs by quaternary amine reaction.The morphology of GO-PAmMeIs were characterized by SEM and TEM.FT-IR and TGA were used to determine the composition and structure of GO-Br and GO-PAmMeI.It was found that the amount of grafted polymer increased with the increasing amount of corresponding monomer,implying that the in situ ATRP method can be controlled to a certain extent.Three kinds of small sized superparamagnetic Fe₃O₄ nanoparticles were prepared by high temperature liquid pyrolysis method and deposited onto the surface of GO-PAmMeI by electrostatic adsorption.TEM,HRTEM and AFM were used to characterize the morphology of Fe₃O₄ nanoparticles and Fe₃O₄@GO-PAmMeI.The corresponding crystal structure and the magnetic property were characterized by XRD and magnetometer,respectively.Finally,the removal efficiency of Fe₃O₄@GO-PAmMeI adsorbents to bisphenol A was investigated and the good adsorption efficiency was found.