聚苯胺导电复合物二次掺杂的基材效应

Matrix Effect of Secondary Doping in Polyaniline Composite

对十二烷基苯碗酸掺杂的聚苯胶（PAn）与氯磺化聚乙烯（CSPE）或苯乙烯一丁二烯一苯乙烯三嵌段共聚物（SBS）形成的复合物的二次掺杂进行了研究．二次掺杂的复合膜经反掺杂后的UV-Vis吸收光谱在580～800nm处呈现宽的吸收，证实了二次掺杂后PAn主链的展开，同时表明PAn在CSPE中的展开较在SBS中更充分．ESR动态测试表明二次掺杂诱导主链的载流子间相互作用有2种方式：PAn／CSPE中的单极化子转变为双极化子；PAn／SBS中的单极化子自旋-自旋相关增加，这可由复合物的相结构来解释．WAXD和SEM的测试结果支持了以上分析．

Secondary doping by m-cresol in polyaniline composite, which was prepared by insitu emulsion po1ymerization technique and cast from solution, was studied by UV-Vis-NIR,ESR, WAXD and so on. The po1yaniline content of the composite used in the present studyis 11. 0% (wt). After secondary doping and then dedoping the composite showed a new ab-sorbance at 580~ 800 nm, which directly demonstrated the increase of conjugation lengththrough expanding polyaniline backbone. The difference of absorbance intensity at 600~800nm implies that polyaniline backbone can expand more completely in CSPE matrix than inSBS. The results from ESR in situ measurement show two kinds of interaction between thecarriers of conductive backbone: after secondary doping, ESR intensity of PAn/CSPEmarkedly decreased and aH,, kept constant, which indicates that secondary doping inducedipolaron: secondary doping enhanced aH,, of PAn/SBS from 3. O× 10-4 T to 5. 6 × 10-4 Tbut the intensity of ESR did not markedly change, which means that secondary dopingcaused spin-spin interaction of polarons between conductive backbone. The results above canbe explained by phase structure of composite caused by compatibility between polyaniline andmatrix. It was found from WAXD of the composite after secondary doping that PAn/SBShad longer-range order crystal peak at 2. 4.(2θ) whereas PAn/CSPE had not. SEM was alsotaken for composites. The results supported the difference between two kinds of compositein phase structure-