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以对苯二胺为原料合成了二硫代氨基甲酸盐过渡金属[Ni(Ⅱ),Pd(Ⅱ),Pr(Ⅱ)]配合物及其它相应脱质子产物卡宾二硫代胺基甲酸盐配合物.通过元素分析,IR,UV测试表征.对该系列配合物用四波混频方法,研究了它们的三阶非线性光学性质.结果表明,平面型二硫代甲酸盐配合物有较强的三阶非线性光学效应.并且它们脱去质子形成的配合物共轭体系更大,其三阶非线性光学效应明显提高. 相似文献
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二次掺杂对聚苯胺导电复合物性能的影响 总被引:3,自引:1,他引:3
研究了聚苯胺与(苯乙烯-丁二烯)三嵌段共聚物或氯碘化聚乙烯复合物在间甲酚二次掺杂前后电导率的变化(提高2个数量级),根据二次掺杂使聚苯胺复合物增强永久形变和断面形貌脆断一次掺杂使卷曲的聚苯胺链展开并通过这间的弱相互作用而自行组成导电能通路,复合物二次掺杂前后的抗张强度和伸长率变化不大,说明其主链间的弱相互作用对应力无贡献,此外,还研究了二次掺杂对复合物在中性和酸必南中电致变色活性的影响。 相似文献
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在SM1和ZINDO方法基础上,按完全态求和公式计算分子二阶非线性光学系数β(ijk)和三阶非线性光学系数γ(ijkl),并对含偶氛功能团的双快类衍生物的二阶、三阶非线性光学性质进行了系统的理论研究.即在基础上,在分子左端引入推电子基N(CH3)2,右端分别引入推电子基CH2OH、2,5-二氮-4-硫甲苯基,研究取代基变化时β、γ变化的规律.对计算结果所反映的规律性在微观上给予了解释. 相似文献
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合成了两种新的金属双噻吩类复合物:(苄基三乙基铵)双(1,3-二硫杂环戊烯-2-硫酮-4,5-二巯基)-金(BTEAADT)和(苄基三乙基铵)双(1,3-二硫杂环戊烯-2-硫酮-4,5-二巯基)-镍(BTEANDT).采用Z扫描方法,在皮秒脉冲下,分别测试了两种材料的乙腈溶液在532和1064nm的三阶非线性光学特性.Z扫描的结果表明,BTEAADT的乙腈溶液在532nm具有反饱和吸收效应,在1064nm非线性吸收效应可以忽略且在两种波长都有自散焦效应,三阶非线性折射率为负值.BTEANDT的乙腈溶液在532nm非线性吸收效应可以忽略,在1064nm具有饱和吸收效应且在两种波长都有自聚焦效应,三阶非线性折射率为正值.分析了造成这种差异的原因.经过计算得到了两种材料在532和1064nm的三阶非线性折射率,三阶非线性吸收系数,三阶非线性极化率和超极化率.BETAADT的非线性折射率在532nm为-1.685×10-18m2·W-1,在1064nm为-1.459×10-18m2·W-1;BTEANDT的非线性折射率在532nm为1.452×10-18m2·W-1,在1064nm为7.311×10-18m2·W-1.两种材料的三阶非线性吸收系数,三阶非线性极化率和超极化率的数量级分别是10-11m·W-1,10-13esu和10-31esu.结果表明这两种材料在非线性光学领域有潜在的应用价值. 相似文献
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聚合物非线性光学材料 总被引:3,自引:0,他引:3
最近,有机非线性光学材料已引起了人们极大的兴趣。一些可极化有机分子具有很大的分子超极化率,可惜,受晶体对称性的限制仅有少数晶体具有二阶非线性光学效应。极化聚合物可以产生统计非中心对称的环境,使材料的二阶特性显示出来。本文在简单介绍了有机非线性光学和极化的原理后,综述了聚合物二阶非线性光学材料的研究进展。此外,对聚合物的三阶非线性光学效应的研究也作了介绍。 相似文献
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在盐酸溶液中通过原位聚合法制备了磁性聚苯胺/镧取代锂镍铁氧体(LiNi0.5La0.02Fe1.98O4)纳米复合物。在外加磁场下纳米复合物表现出了磁滞现象,其饱和磁化强度(Ms)和矫顽力(Hc)随铁氧体含量的改变而变化。用X-射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)以及振动样品磁强计(VSM)等对纳米复合物进行了表征。TEM和SEM表明纳米复合物具有核-壳结构。XRD、FT-IR和UV-Vis光谱揭示了纳米复合物中铁氧体与聚苯胺之间存在着一定的键合作用,并探讨了铁氧体与聚苯胺之间的键合机制。 相似文献
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偶氮苯聚合物(PAZOS)的合成及其三阶非线性光学特性 总被引:1,自引:0,他引:1
合成及表征了一种偶氮苯聚合物聚「3-甲基-4-二(N,N-氧亚乙基)氨基-4-硝基偶氮苯癸二酰」通过简并四波混频方法研究了这种聚合物膜的三阶非线性光学性质,测得三三阶非线性光学系数X^(3)为6.6*10^-6esu,并考察了其相位共轭光产生特性及光致异构动力学。 相似文献
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A novel route for producing polymer blends by reactive extrusion is described, starting from poly (vinyl chloride)/methyl methacrylate (PVC/MMA) dry blend and successive polymerization of MMA in an extruder. Small angle X‐ray scattering (SAXS) measurements were applied to study the monomer's mode of penetration into the PVC particles and to characterize the supermolecular structure of the reactive poly(vinyl chloride)/poly(methyl methacrylate) (PVC/PMMA) blends obtained, as compared to the corresponding physical blends of similar composition. These measurements indicate that the monomer molecules can easily penetrate into the PVC sub‐primary particles, separating the PVC chains. Moreover, the increased mobility of the PVC chains enables formation of an ordered lamellar structure, with an average d‐spacing of 4.1 nm. The same characteristic lamellar structure is further detected upon compression molding or extrusion of PVC and PVC/PMMA blends. In this case the mobility of the PVC chains is enabled through thermal energy. Dynamic mechanical thermal analysis (DMTA) and SAXS measurements of reactive and physical PVC/PMMA blends indicate that miscibility occurs between the PVC and PMMA chains. The studied reactive PVC/PMMA blends are found to be miscible, while the physical PVC/PMMA blends are only partially miscible. It can be suggested that the miscible PMMA chains weaken dipole–dipole interactions between the PVC chains, leading to high mobility and resulting in an increased PVC crystallinity degree and decreased PVC glass transition temperature (Tg). These phenomena are shown in the physical PVC/PMMA blends and further emphasized in the reactive PVC/PMMA blends. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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FTIR studies of PVC/PMMA blend based polymer electrolytes 总被引:1,自引:0,他引:1
Ramesh S Leen KH Kumutha K Arof AK 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,66(4-5):1237-1242
The polymer electrolytes composing of the blend of polyvinyl chloride-polymethyl methacrylate (PVC/PMMA) with lithium triflate (LiCF3SO3) as salt, ethylene carbonate (EC) and dibutyl phthalate (DBP) as plasticizers and silica (SiO2) as the composite filler were prepared. FTIR studies confirm the complexation between PVC/PMMA blends. The CCl stretching mode at 834 cm-1 for pure PVC is shifted to 847 cm-1 in PVC-PMMA-LiCF3SO3 system. This suggests that there is interaction between Cl in PVC with Li+ ion from LiCF3SO3. The band due to OCH3 at 1150 cm-1 for PVC-PMMA blend is shifted to 1168 cm-1 in PVC-PMMA-LiCF3SO3 system. This shift is expected to be due to the interaction between Li+ ion and the oxygen atom in PMMA. The symmetric vibration band and the asymmetric vibration band of LiCF3SO3 at 1033 and 1256 cm-1 shifted to 1075 and 1286 cm-1 in the DBP-EC plasticized PVC-PMMA-LiCF3SO3 complexes. The interaction between Li+ ions and SiO2 will lead to an increase in the number of free plasticizers (which does not interact with Li+ ions). When the silica content increases from 2% to 5%, the intensity of the peak at 896 cm-1 (due to the ring breathing vibration of free EC) increases in PVC-PMMA-LiCF3SO3-DBP-EC system. 相似文献
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《高分子科学》2016,(6)
This article addresses the synthesis of organically tailored Ni-Al layered double hydroxide(ONi-Al LDH) and its use in the fabrication of exfoliated poly(methyl methacrylate)(PMMA) nanocomposites. The pristine Ni-Al LDH was initially synthesized by co-precipitation method and subsequently modified using sodium dodecyl sulfate to obtain ONi-Al LDH. Nanocomposites of PMMA containing various amounts of modified Ni-Al LDH(3 wt%?7 wt%) were synthesized via solvent blending method to investigate the influence of LDH content on the properties of PMMA matrix. Several characterization methods such as X-ray diffraction(XRD), transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FTIR), rheological analysis, differential scanning calorimetry(DSC) and thermo gravimetric analysis(TGA), were employed to examine the structural, viscoelastic and thermal properties of PMMA/OLDH nanocomposites. The results of XRD and TEM examination confirm the formation of partially exfoliated PMMA/OLDH nanocomposites. The FTIR results elucidate that the characteristic bands for both pure PMMA and modified LDH are present in the spectra of PMMA/OLDH nanocomposites. Rheological analyses were carried out to examine the adhesion between polymer matrix and fillers present in the nanocomposite sample. The TGA data indicate that the PMMA nanocomposites exhibit higher thermal stability when compared to pure PMMA. The thermal decomposition temperature of PMMA/OLDH nanocomposites increases by 28 K compared to that of pure PMMA at 15% weight loss as a point of reference. In comparison with pure PMMA, the PMMA nanocomposite containing 7 wt% LDH demonstrates improved glass transition temperature(Tg) of around 3 K. The activation energy(Ea), reaction orders(n) and reaction mechanism of thermal degradation of PMMA/OLDH nanocomposites were evaluated using different kinetic models. Water uptake capacity of the PMMA/OLDH nanocomposites is less than that of the pure PMMA. 相似文献
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采用涂层法在玻璃基底上分别制备了纯聚氯乙烯(PVC)薄膜和添加水热法制备的钙钛矿型铌酸银(AgNbO3)光催化剂的复合薄膜(PVC-wAgNbO3, 其中w为AgNbO3的质量分数), 在500 W氙灯照射120 min条件下进行了薄膜的光催化降解实验. 利用X射线衍射仪(XRD)、 扫描电子显微镜(SEM)和傅里叶变换红外光谱仪(FTIR)等对光照前后薄膜的形貌及光催化降解过程进行了表征. 结果表明, 在光催化降解过程中纯PVC薄膜失重率为4.09%, 而PVC-3%AgNbO3, PVC-6%AgNbO3, PVC-9%AgNbO3和PVC-15%AgNbO3复合薄膜分别失重20.36%, 23.52%, 27.62%和33.83%. AgNbO3光催化剂加速了PVC薄膜的降解, 且随着AgNbO3光催化剂添加量的增加, PVC薄膜的光催化降解速率不断增大. 相似文献
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用共混和共聚法改性聚苯胺及其电流变液的研究 总被引:1,自引:0,他引:1
通过共混和表面接枝共聚两种方法改性聚苯胺,制备聚苯胺(PAn)复合粒子并用它们组成活性较高的电流变(ER)液.研究了PAn复合粒子的结构与ER液性能的关系.结果表明在PAn粒子表面涂覆聚乙烯醇或接枝聚丙烯酰胺等与PAn能形成氢键或有化学键连接的绝缘物质可以既提高其ER液的电诱导屈服应力又降低漏电流密度. 相似文献
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Graphite nanosheets (NanoG) were prepared by treating the expanded graphite with sonication in aqueous alcohol solution. Nanocomposites of poly(methyl methacrylate) (PMMA) with NanoG were prepared via an in situ polymerization of MMA in the presence of NanoG with the aid of sonication. The nanocomposites were then dispersed with chloroform (CHCl3) and casted on glass slides to form conducting films. The percolation threshold of PMMA/NanoG conducting films at room temperature was as low as 0.31 vol%, much lower than that of the composites filled with conventional graphite particles. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area diffraction (SAD) and etc. were used to characterize the structure of the graphite nanosheets and the nanocomposites. Results showed that the high-aspect-ratio structure of graphite nanosheets played an important role in forming conducting network in PMMA matrix. The conducting behavior of the composite was interpreted by percolation theory. 相似文献
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Surface modified silver nanoparticles dispersed in chloroform were encapsulated in poly(methylmethacrylate) (PMMA) by in-situ radical polymerization of methyl methacrylate initiated by 2,2′-azobisisobutyronitrile. The particle size distribution of colloidal silver nanoparticles was determined using transmission electron microscopy. The obtained transparent nanocomposite films were characterized using UV-vis spectroscopy, 1H NMR spectroscopy and gel permeation chromatography. Effective medium Maxwell-Garnett theory was used in order to explain optical properties of nanocomposite films taking into account inhomogeneous spatial distribution of silver nanoparticles in PMMA matrix. The influence of the silver nanoparticles on the thermal properties of the PMMA matrix was investigated using thermo-gravimetric analysis and differential scanning calorimetry. Thermo-oxidative stability of the PMMA in the presence of low content of inorganic phase is significantly improved. The glass transition temperatures of nanocomposites are slightly lower compared to the pure polymer. 相似文献
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This article addresses the synthesis of organically tailored Ni-Al layered double hydroxide (ONi-Al LDH) and its use in the fabrication of exfoliated poly(methyl methacrylate) (PMMA) nanocomposites. The pristine Ni-Al LDH was initially synthesized by co-precipitation method and subsequently modified using sodium dodecyl sulfate to obtain ONi-Al LDH. Nanocomposites of PMMA containing various amounts of modified Ni-Al LDH (3 wt%-7 wt%) were synthesized via solvent blending method to investigate the influence of LDH content on the properties of PMMA matrix. Several characterization methods such as X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), rheological analysis, differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), were employed to examine the structural, viscoelastic and thermal properties of PMMA/OLDH nanocomposites. The results of XRD and TEM examination confirm the formation of partially exfoliated PMMA/OLDH nanocomposites. The FTIR results elucidate that the characteristic bands for both pure PMMA and modified LDH are present in the spectra of PMMA/OLDH nanocomposites. Rheological analyses were carried out to examine the adhesion between polymer matrix and fillers present in the nanocomposite sample. The TGA data indicate that the PMMA nanocomposites exhibit higher thermal stability when compared to pure PMMA. The thermal decomposition temperature of PMMA/OLDH nanocomposites increases by 28 K compared to that of pure PMMA at 15% weight loss as a point of reference. In comparison with pure PMMA, the PMMA nanocomposite containing 7 wt% LDH demonstrates improved glass transition temperature (T g) of around 3 K. The activation energy (E a), reaction orders (n) and reaction mechanism of thermal degradation of PMMA/OLDH nanocomposites were evaluated using different kinetic models. Water uptake capacity of the PMMA/OLDH nanocomposites is less than that of the pure PMMA. 相似文献