导电高分子PEDOT/PSS稳定的Pt3Co纳米粒子的制备及电、磁性

利用一步共还原法在导电高分子聚二氧乙基噻吩/聚对苯乙烯磺酸(PEDOT/PSS)水溶液中合成了磁性纳米复合物Pt₃Co-PEDOT/PSS. 利用透射电镜(TEM)、X射线衍射(XRD)、拉曼光谱、超导量子干涉仪(SQUID)对其进行了表征.结果表明Pt₃Co纳米粒子为面心立方结构(fcc), 粒子平均粒径为9.6 nm, 标准偏差为2.4 nm. 用旋转涂膜法制备的Pt₃Co-PEDOT/PSS薄膜导电率()在1.6～4.0 S/cm之间. 当温度在阻塞温度(T_B, 110.5 K)以上时, 纳米复合物Pt₃Co-PEDOT/PSS显示出超顺磁性, 低于T_B时呈铁磁性, 在5 K时其剩磁(M_r)和矫玩力(H_c)分别为4.1 emu/g和701 Oe(奥斯特).     

镝掺杂铁氧体纳米晶的制备、表征和磁性

采用化学共沉淀法制备出了镝掺杂铁氧体纳米晶, 利用透射电子显微镜(TEM)、X射线衍射仪(XRD)、傅立叶红外光谱仪(FTIR)、古埃磁天平、振动样品磁强计(VSM)、X射线能谱仪(EDX)等仪器对产物进行了表征, 研究了Dy^3＋掺杂量对铁氧体纳米晶的结构、磁性和粒度的影响. 结果表明: 适量稀土元素镝离子的掺杂可以提高尖晶石型铁氧体的磁性、降低矫顽力, 当n(Fe^3＋)∶n(Dy^3＋)＝14∶1时其磁性最强. Dy^3＋替代或充填进入了尖晶石晶格, 且主要占据B位. 掺杂了镝的铁氧体磁性纳米粒子粒度变小, 且分布更集中、均匀, 当Dy^3＋加入量为n(Fe^3＋)∶n(Dy^3＋)＝14∶1时铁氧体纳米粒子的平均粒径由掺杂前的14 nm降低到到8 nm. 这种具有超顺磁性的软磁铁氧体纳米晶可应用于纳米磁液领域.     

FeOOH明胶复合纳米粒子的制备与表征

采用两步法制备具有弱磁性的FeOOH纳米粒子和FeOOH明胶复合纳米粒子. 透射电镜、扫描电镜、红外光谱、X射线衍射和磁滞回线等测量结果表明: 在一定FeCl₃/Fe₂(SO₄)₃/H₂O摩尔比条件下, 加入十二烷基苯磺酸钠(ABS)溶液, 可制备粒径为30～150 nm弱磁性FeOOH纳米粒子, 其磁性可达6.5×10^－6 emu/g. 弱磁性FeOOH纳米粒子可被明胶包裹. 随着FeCl₃/Fe₂(SO₄)₃摩尔比减小或明胶浓度增加, 纳米球粒径增大, 磁性降低. 随着固化时间增加, FeOOH明胶复合纳米粒子的粒径先增大后减小.     

憎水性三金属纳米粒子的合成、表征及磁性

以磺基琥珀酸二辛酯钠盐(AOT)为表面活性剂,采用反胶束法合成了憎水性CoFe/Au纳米粒子, 利用配体交换、水洗等去除AOT并使纳米粒子分级.采用紫外-可见光谱(UV-Vis)、透射电镜(TEM)、X射线衍射(XRD)、X射线电子能量散射(EDX)及等离子发射光谱 (ICP)等对产物进行了表征,通过超导量子干涉仪(SQIUD)研究了纳米粒子的磁性质.结果表明,反胶束法合成的CoFe/Au三金属纳米粒子具有较好的单分散性和稳定性,平均粒径约为4 nm.当外磁场强度为1.5×10⁴ A/m时,阻塞温度T_b为65 K,温度高于T_b时纳米粒子显示出超顺磁性,低于T_b时呈铁磁性,在5 K时其矫顽力(Hc)达4.67×10⁴ A/m.     

用于磁性靶向治疗肺纤维化的聚多巴胺包覆的Fe3O4/甲强龙/环磷酰胺复合超粒子

肺纤维化是一种致命性肺部疾病, 目前临床常规的甲强龙(MPS)联合环磷酰胺(CTX)治疗方法存在明显的不良反应. 基于降低药物毒副作用的目的, 本文设计了一种聚多巴胺(PDA)包覆的Fe₃O₄纳米粒子/甲强龙/环磷酰胺复合超粒子(Fe₃O₄/MPS/CTX@PDA SPs), 提出磁性靶向治疗肺纤维化的思路. 从预制的油溶性Fe₃O₄纳米粒子出发, 通过水包油微乳液模板法制备了Fe₃O₄ 超粒子(SPs), 并在进一步包覆PDA壳层的过程中引入MPS和CTX, 制备了Fe₃O₄/MPS/CTX@PDA SPs, 考察了Fe₃O₄/MPS/CTX@PDA SPs的稳定性、 磁性、 对MPS和CTX的负载及释放, 分析了其生物毒性, 并建立动物模型验证了其磁性靶向功能.     

磁性荧光双功能复合纳米粒子Fe3O4@SiO2@ZrO2:Tb3+的合成和表征

通过原位反应合成法成功合成了一种新型水溶性的磁性荧光复合纳米粒子Fe₃O₄@SiO₂@ZrO₂:Tb³⁺,并通过扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)、红外光谱仪(FT-IR)、磁性测试仪和荧光(PL)光谱对其形貌、尺寸、相组成、磁性和荧光性能进行了表征。 结果表明,核(Fe₃O₄@SiO₂)壳(ZrO₂:Tb³⁺)结构组成的磁性荧光复合纳米粒子具有超顺磁性,其饱和磁化强度达到36 emu/g,并且在494 nm(⁵D₄→⁷F₆)、549 nm(⁵D₄→⁷F₅)、587 nm(⁵D₄→⁷F₄)和625 nm(⁵D₄→⁷F₃)处具有4个Tb³⁺特有的荧光发射光谱带峰值。 磁性荧光双功能的复合纳米粒子在生物医学领域具有潜在的应用价值。     

聚吡咯/石墨复合对电极在染料敏化太阳能电池中的应用研究

通过化学氧化法制备了聚吡咯纳米粒子, 并将其与石墨共混旋涂于ITO导电玻璃上, 作为染料敏化太阳能电池的对电极. 通过SEM观察到聚吡咯纳米粒子粒径在80～100 nm之间, 循环伏安测试表明聚吡咯电极对I₂/I^－电解质氧化还原体系具有较好的催化能力. 光伏电池的电化学交流阻抗测试结果说明掺入石墨后可有效降低聚吡咯对电极的电荷转移阻抗. 以钌染料N719为光敏剂, 聚吡咯/石墨复合电极为对电极组装成的染料敏化太阳能电池, 在AM 1.5 (100 mW•cm^－2) 的模拟太阳光照射下, 得到6.01%的光电转换效率, 达到相同条件下铂对电极性能的92%.     

双官能Fe3O4/CdSe/CdS荧光磁性复合物的制备和表征

采用化学共沉淀法, 以FeCl₂•4H₂O和FeC1₃•6H₂O为原料制备磁性Fe₃O₄纳米颗粒(MNPs), 采用氨基酸对其进行修饰使其表面连上氨基. 用巯基乙酸作为稳定剂合成了水溶性的CdSe/CdS量子点, 并利用偶联剂1-乙基-3-(3-二氨丙基)碳二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)连接氨基修饰的Fe₃O₄和带有羧基的CdSe/CdS, 成功制备了Fe₃O₄/CdSe/CdS荧光磁性纳米颗粒. 该荧光磁性纳米复合物保留了CdSe/CdS量子点优异的荧光特性, 平均粒径在40 nm左右; 磁化曲线表明此纳米复合物具有超顺磁性. 这种双官能复合纳米颗粒有望成为新型荧光磁性双标记复合微粒而广泛应用于免疫检测、荧光追踪、磁性分离等领域.     

磁性介孔纳米粒子的制备及对抗癌药紫杉醇的传输

以十六烷基溴化铵(CTAB)为结构导向剂, 正硅酸乙酯(TEOS)为硅源, 在碱性环境下经过自组装过程对单分散性磁性Fe₃O₄纳米粒子进行包覆, 制备出磁性硅基介孔纳米粒子Fe₃O₄@SiO₂. 结合X射线衍射、 傅里叶变换红外光谱(FTIR)、 透射电子显微镜(TEM)以及氮气吸附-脱附等技术对Fe₃O₄@SiO₂粒子进行表征. 结果表明Fe₃O₄@SiO₂纳米粒子具有球形形貌, 平均直径约为150 nm, 蠕虫状介孔结构, 比表面积为932 m²/g, 孔径为2.5 nm且分布较均匀, 包覆后Fe₃O₄的结构得以保持, 同时材料具有很好的磁响应能力. 以抗癌药紫杉醇(Paelitaxel, TXL)为模型药物进行负载, 实验结果表明, Fe₃O₄@SiO₂对TXL的负载能力为80 mg/g, TXL-Fe₃O₄@SiO₂对TXL的缓释时间持续120 h以上, 累积释放量达到30 mg/g. 通过噻唑蓝比色(MTT)法测量了TXL-Fe₃O₄@SiO₂粒子对体外培养的HeLa细胞的细胞毒性, 与相同浓度的TXL相比, TXL-Fe₃O₄@SiO₂对HeLa细胞的抑制率明显增高.     

基于位形熵模型的山梨醇玻璃焓松弛的量热分析

利用DSC技术考察了无定形山梨醇体系的焓松弛行为, 在10 K•min^－1的升温速率下测定了经历不同降温速率(0.5～20 K•min^－1)的山梨醇在玻璃化转变(T_g)前后的比热容[c_p(T)]. 利用基于位形熵演变的焓松弛现象学模型(GR模型)模拟了实验数据. 不论是否假设松弛过程存在一个亚稳极限态, 模型参数均能很好地重现经历不同热历史体系的升温c_p(T)曲线. 在物理意义明确的模型参数组中, 除了非指数参数随降温速率的增加而增加外, 其余均不随热历史的变化而变化. 拟合较低降温速率下c_p(T)曲线获得的GR模型参数的预测力明显好于在较大降温速率下获得的结果. 由于松弛时间对拟合过程中选择的“固定参数”的取值很敏感, 因此模型能否预测体系的比热容不能看成确定松弛时间的唯一依据. 在利用GR模型分析无定形山梨醇体系的脆度时, 如果选择极限假想温度作为T_g, 会导致计算结果明显小于文献值.     

Simultaneous synthesis of silver nanoparticles and poly(2,5‐dimethoxyaniline) in poly(styrene sulfonic acid)

Silver nanoparticles were formed in situ along with poly(2,5‐dimethoxyaniline) (PDMA) in an interconnected network matrix (reactor), comprising the electronic conductive polymer, PDMA, and a polyelectrolyte, poly(styrene sulfonic acid) (PSS), through the simultaneous reduction of Ag⁺ ions and polymerization of 2,5‐dimethoxyaniline. In situ ultraviolet‐visible spectroscopy showed that peaks corresponding to the plasmon resonance of silver nanoparticles at 411 nm and the polaronic transition of PDMA at 438 nm provided evidences for the simultaneous formation of silver nanoparticles and PDMA. Transmission electron microscopy and size distribution analysis revealed the presence of spherical silver nanoparticles with an average diameter of 12 nm in the composite. X‐ray photoelectron spectroscopy showed that the amine units in PDMA changed to imine units upon the formation of silver nanoparticles. A comprehensive mechanism for the formation of the PDMA‐PSS‐Ag nanocomposite is proposed. A 10‐fold increase in the conductivity was noticed for the PDMA–PSS–Ag nanocomposite (1 S/cm) in comparison with the PDMA–PSS composite (0.1 S/cm). © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3843–3852, 2006     

Oxidoreductase Catalyzed Polymerization of 3-Methylpyrrole

A one-pot, environmentally friendly enzymatic method is described for the synthesis a polypyrrole derivative, poly(3-methylpyrrole) (poly(3-MP)) in an aqueous solvent system. The enzyme, soybean peroxidase (SBP), was shown to successfully polymerize the beta functionalized pyrrole monomer. The resulting polymer was semiconducting, thermally stable, and exhibited bipolaron absorptions when synthesized in the presence of poly(sodium 4-styrenesulfonate) (PSS). Polymers synthesized in the presence of 10-camphor sulfonic acid (CSA) were found to exhibit slightly higher conductivity values, but were less thermally stable compared to poly(3-MP) polymerized in the presence of PSS. This work should stimulate further interest in expanding the use of enzymes as catalysts for the polymerization of other pyrrole derivatives, as well as other classes of conjugated polymers.     

聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸盐热电性能的 提升策略研究进展

近十年,有机聚合物及其复合热电材料与柔性器件取得了显著进展,在废热回收利用、可穿戴电子学、软体机器人和物联网等领域有广泛的应用.其中,聚(3,4-乙烯二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS)是迄今研究最多也是性能最高的聚合物体系.本文对近年来有关PEDOT:PSS热电性能有效提升主要策略的文献报道进行了总结.首先,从PEDOT:PSS的二次掺杂/去掺杂、酸或碱处理和离子液体处理方面等,重点论述了掺杂/去掺杂策略的研究进展;然后,分别从改善聚集态结构、构筑PEDOT微纳米结构和与碳纳米材料复合等3个方面,重点介绍了采用此3种策略提升PEDOT:PSS热电性能的研究进展;最后,对该领域进行总结,提出了开展进一步研究的建议,并对其未来发展前景进行展望.     

二甲基亚砜改性聚(3,4-乙撑二氧噻吩):聚苯乙烯磺酸薄膜的研究及应用进展

二甲基亚砜(DMSO)被称为“万能溶剂”,除了在化学、医学、化妆品等领域的常规应用,在有机电子领域也有展现出特色应用。 聚(3,4-乙撑二氧噻吩):聚苯乙烯磺酸(PEDOT:PSS)是一类卓越的水分散性导电聚合物材料,具有优异的可加工性、混合性、生物兼容性、成膜性以及可商业规模生产等优势,被广泛应用于抗静电涂层、透明电极、有机太阳能电池、超级电容、生物传感等新材料和绿色能源领域。 DMSO对调控PEDOT:PSS薄膜的形貌、导电、热电、功函,界面接触、力学、自修复等性能具有重要作用。 基于我们团队及国内外学者在本领域的研究成果,本文系统综述了DMSO对PEDOT及其衍生物:PSS(PEDOTs:PSS)作用的效果及其机制,探讨了应用中面临的问题与挑战。     

Pt羰基簇合物在NaY内的合成机理

利用IR，EXAFS, ~(13)CO同位素交换反应及与NO作用等手段研究了Pt羰基簇合物[Pt_3(CO)_6]~(2-)_n(n＝3,4)在NaY分子筛超笼内的合成机理．在氧化样品Pt~(2+)/NaY上300－373 K的还愿羰基化过程中，首先Pt~(2+)与CO反应生成PtO(CO)物种(波数σ_(CO)＝2110 cm~(-1))，然后聚集成“Pt_3(CO)_6”(σ_(CO)＝2112，1896和1841 cm~(-1))，最后生成深绿色的Pt羰基簇合物Pt_(12)(CO)_(24)]~(2-)/NaY(σ_(CO)＝2080，1824 cm~(-1))．“Pt_3(CO)_6”的羰基在室温下能迅速地与~(13)CO发生交换，而[Pt_3(CO)_6]~(2-)_n(n＝3,4)的羰基与~(13)CO的同位素交换即使在343 K也进行得很慢，室温下，NO能逐步破坏Pt羰基簇合物的层间和层内Pt－Pt键，得到中间物种“Pt_3(CO)_6”和PtO(CO)，同时在气相产生CO_2和N_2O．而由上述两中间物种出发，300－353 K温度下，在CO气氛中的还原羰基化又能可逆地得到原羰基簇合物．     

Effect of H2SO4 Solution Treatment on Adhesion,Charge Transfer,and Catalytic Performance of Screen-Printed PEDOT:PSS

Post-treatment was performed for poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films screen-printed on fluorine-doped tin oxide (FTO) substrates, to improve their charge transfer efficiency. Different H₂SO₄ solutions, including concentrated H₂SO₄ and H₂SO₄ diluted with H₂O or dimethyl sulfoxide (DMSO), were adopted during the post-treatment. The adhesion of the as-treated films was evaluated by adhesive tape peeling tests, the surface morphology and vertical charge transfer from the films to the substrates were investigated by current-sensing atomic force microscopy, and the catalytic activities toward I₃⁻ reduction of PEDOT:PSS films were characterized by electrochemical measurements. It is discovered that selecting proper H₂SO₄ solutions is crucial to improve the charge transfer efficiency and catalytic performance while maintaining reliable adhesion of the film on the substrates, with H₂SO₄/DMSO performing best as the solution for post-treatment. A mechanistic explanationis proposed based on different interactions among solution, PEDOT:PSS, and the substrate for various post-treatment solutions.     

Synthesis,characterization and properties of multifunctional poly(arylene ether nitriles) (PEN)/CNTs/Fe3O4 nanocomposites

In this study, a novel multifunctional poly(arylene ether nitriles)(PEN)/carbon nanotubes/Fe₃O₄ nanocomposite with high tensile strength, magnetic, and electrical properties was investigated. First, we synthesized the monodisperse Fe₃O₄ nanoparticles on the surface of the multiwalled carbon nanotubes and then the hybrid material was compounded with PEN through the solution‐casting method. The SEM and TEM images indicated that the monodisperse Fe₃O₄ nanoparticles, with the diameters of 70∼80 nm, were self‐assembled along CNTs via the covalent bond method, which was confirmed by FTIR and XRD. The results of tensile properties showed that the tensile strength and modulus reached their highest values at the CNTs/Fe₃O₄ loading content of 1 wt % and both were greatly enhanced after heat treatment. Electrical conductivity of the polymer was dramatically enhanced at the low loading level of CNTs/Fe₃O₄; the electrical percolation of was in the range of 5∼8 wt % of CNTs/Fe₃O₄. The magnetic study showed that the saturation magnetization (M_s) of PEN/CNTs/Fe₃O₄ nanocomposites increased with the increase of CNTs/Fe₃O₄ loading content, and the coercive force (H_c) of the nanocomposite was independent of the CNTs/Fe₃O₄ content. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011     

Ag/WO3纳米复合膜的制备及其电致变色性质和器件的研究

通过真空镀膜方法制备的纳米Ag薄膜均匀致密, 表面光滑. 然后通过电化学方法在Ag纳米薄膜上沉积一层三氧化钨(WO3), 制备纳米Ag/WO3复合膜. 并在此基础上构筑五层式玻璃/ITO/纳米Ag-WO3复合膜/固态电解质/聚(3-甲基噻吩)/ITO/玻璃电致变色器件. 实验结果表明, 与传统的WO3膜相比, 纳米Ag/WO3复合膜具有更好的电化学活性、更高的对比度、更短的响应时间, 以及更好的稳定性. 由该复合膜组装的电致变色器件工艺简单, 电致变色性能良好.     

Enhancement of dispersion stability of inorganic additives via poly(sodium-4-styrenesulfonate) treatment geared to hydrogel applications

This study reports the preparation of poly(sodium-4-styrene sulfonate) (PSS) treated bentonite and clinoptilolite to prevent the agglomeration and sedimentation of these inorganic fillers during the preparation of hydrogel. For this purpose PSS treated fillers were prepared by using various techniques (dip and dry, hydrothermal, one-step ball milling and ultrasonication methods). The most suitable technique for preparing these PSS treated inorganic fillers (abbreviated as BP-dip and CP-dip) was the dip and dry method. BP-dip and CP-dip based polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) composite hydrogels were prepared using the freeze/thawing method after the addition of one of BP-dip and CP-dip inorganic fillers in various amounts. The swelling properties, stability behaviors and Rhodamine B (RhB) adsorption of the composite hydrogels were studied. It was found that the swelling degrees of CP-dip and BP-dip based composite hydrogels with 25 mg of filler were higher than that of all other samples. The kinetic mechanism of RhB adsorption process and the related characteristic kinetic parameters were investigated by Pseudo kinetic models. The adsorption kinetics results for RhB adsorption were found best fitted with pseudo-second-order kinetics model. The maximum RhB adsorption capacity was determined to be for PVA/PVP-CP-dip25, which was 3.3 times higher than that of the unfilled PVA/PVP hydrogel.