新型聚2-氨基苯磺酸改性TiO_2纳米颗粒的制备及光催化性能

为提高TiO_2的光催化活性,利用原位氧化聚合法制备聚2-氨基苯磺酸改性TiO_2(P2ABSA/TiO_2)纳米颗粒,通过TEM、EDS、XRD、UV-Vis DRS和Photocurrent Test进行表征,以亚甲基蓝为模拟污染物,优化纳米材料制备条件,考察初始pH值和P2ABSA/TiO_2浓度对光催化效果的影响,通过捕捉实验判定活性氧物种在光催化过程中的贡献。结果表明:P2ABSA/TiO_2纳米颗粒最优制备条件为P2ABSA、TiO_2和氧化剂的物质的量之比2∶1∶2、HCl浓度1.2mol/L;TiO_2表面存在一层P2ABSA膜,P2ABSA改性没有改变TiO_2的物相和晶粒尺寸;P2ABSA/TiO_2纳米颗粒对可见光的响应提高,光电流密度从18.3μA/cm2提高到28.7μA/cm2;溶液初始pH值由3.93升至11.36,亚甲基蓝脱色率由92.0%提高到99.0%,P2ABSA/TiO_2纳米颗粒浓度最佳值为1.5g/L;活性氧物种在光催化过程中的贡献大小顺序为·OHh+·O-2,P2ABSA对TiO_2的光敏化作用是P2ABSA/TiO_2纳米颗粒光催化活性得到提高的主要原因。     

聚吡咯纳米粒子及聚吡咯-木质素磺酸空心球的制备

以三氯化铁为氧化剂,在静态聚合条件下,分别制备了聚.咯纳米粒子及聚吡咯-木质素磺酸空心球.采用扫描电子显微镜、透射电子显微镜、红外光谱、宽角X射线衍射对聚吡,及聚吡咯-木质素磺酸的形貌和结构进行了表征.研究结果表明,木质素磺酸钠用量对聚吡咯的形貌有重大影响.在元木质素磺酸盐存在,三氯化铁/吡咯物质的量比为1.0,25℃...     

纳米Fe3O4-聚吡咯的相互作用

在合成了同时具有导电性和磁性能的Fe3O4-聚吡咯纳米微球的基础上，使用了光电子能谱(XPS)、IR、UV、TGA等手段研究了纳米Fe3O4-聚吡咯之间的相互作用及作用机理。结果表明，Fe3O4与聚吡咯基体问存在着一定的相互作用。Fe原子3d轨道的空轨道与N原子的孤对电子形成了配位键，正是这种配位键的形成提高了复合物的热稳定性。     

化学共沉淀法制备油溶性Fe_3O_4纳米颗粒

采用化学共沉淀法制备粒径小于10 nm的油溶性Fe3O4纳米颗粒,对其结构和性能进行表征,并讨论氨水加入方式对Fe3O4纳米颗粒形貌和产率的影响。结果表明:油酸成功包覆在反尖晶石型Fe3O4纳米颗粒的表面,并使其在多种油性溶剂中具有良好的分散性能;磁滞回线显示制得的Fe3O4纳米颗粒具有良好的超顺磁性;氨水加入方式的改变对Fe3O4纳米颗粒的生长具有明显的影响,进而影响Fe3O4纳米颗粒的产率。     

TiN/聚吡咯纳米复合材料的制备及表征

采用氨解法制备了纳米氮化钛(TiN)粉体,对纳米TiN粉体进行表面改性,使其均匀分散到吡咯单体中.采用原位聚合法制备了TiN/聚吡咯(PPy)纳米复合材料.对合成的复合材料用X射线衍射(XRD)、透射电镜(TEM)、傅立叶变换红外光谱(FT-IR)、四探针测试仪等方法进行了表征与检测.结果表明:PPy成功地包覆在TiN纳米颗粒表面,形成了纳米TiN/PPy复合材料.复合材料具有优良的电性能.     

3-羟基丁酸-4-羟基丁酸共聚物/醋酸纤维素复合纳米纤维的制备与表征

采用静电纺丝法制备了3-羟基丁酸-4-羟基丁酸共聚物(P(3HB-co-4HB))/醋酸纤维素(CA)复合纳米纤维,并优化了复合纳米纤维的制备工艺,最终可制得直径为356nm,标准方差为0.28的复合纳米纤维。利用扫描电子显微镜、红外光谱、X射线衍射和差示扫描量热分析对复合纳米纤维进行了表征。结果表明,复合纳米纤维表面非常光滑,纤维间呈无序排列,有较高的孔隙;复合纳米纤维的结晶结构与P(3HB-co-4HB)的结晶结构基本相同,少量CA(10%)的加入能促进复合纳米纤维的快速结晶,起到成核剂的作用,从而使纳米纤维的结晶度得到提高,CA加入量过多时,结晶度下降;随着CA含量的增加,复合纳米纤维的玻璃化转变温度从46.6℃下降至21.3℃,而熔融温度变化不大,在130℃附近。     

HRP催化对羟基苯甲酸与对氨基苯磺酸共聚物的制备及性能研究

对羟基苯甲酸(PHBA)与对氨基苯磺酸(SAA)在辣根过氧化物酶(HRP)/H2O2催化下进行自由基共聚反应,合成了PHBA-SAA共聚物。研究了反应温度、体系pH、单体用量、HRP用量、H2O2滴加时间和反应时间对聚合反应的影响。在去离子水150mL与KH2PO4-K2HPO4缓冲溶液50mL组成的溶液中,当PHBA与SAA物质的量之比为2∶1且二者的用量为0.15mol、HRP用量为5mg、17g30%H2O2滴加时间为2h、体系的pH值稳定在8.0时,在30℃下反应3.5h得到了PHBA与SAA的共聚产物,其物质的量产率约为98%。通过FTIR、NMR和GPC表征了产物结构。提出了PHBA与SAA自由基聚合反应机理。应用结果表明,该产物具有助染、复鞣等性能。     

聚3-戊酰基吡咯/多壁碳纳米管复合材料的制备与电导率研究

通过原位化学聚合法制备了聚3-戊酰基吡咯(PVPy)/多壁碳纳米管(MWNTs)复合材料.利用傅里叶变换红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、热重分析(TGA)与四探针法对样品的结构和性能进行了研究.FT-IR表明,PVPy与MWNTs分子间存在相互作用力.TEM显示,3-戊酰基吡咯(VPy)单体仅在MWNTs的外表面发生聚合.XRD谱显示,PVPy/MWNTs复合材料中MWNTs的两个特征结晶峰强度随着VPy/MWNTs原料比增加而逐渐降低,主要表现出PVPy的结晶峰.电导率测试结果表明,通过MWNTs与PVPy复合,可以显著的提高PVPy/MWNTs复合材料的导电性,其电导率分别为2.37 S/cm(VPy/MWNTs=2.5/1)与0.25 S/cm(VPy/MWNTs=5/1).     

水基阳离子聚氨酯/聚吡咯导电材料的原位制备与电阻性能

以N-甲基二乙醇胺(MDEA)为扩链剂,聚乙二醇(PEG1000)、异佛尔酮二异氰酸酯(IPDI)为原料,通过预聚体法制备了系列水基阳离子聚氨酯分散液(CWPU)。再以FeCl3为氧化剂,在CWPU中进行吡咯的原位化学氧化聚合制备聚氨酯/聚吡咯(CW-PU/PPy)复合导电材料。红外光谱图表明PPy与CWPU分子间存在氢键缔合。经PPy改性后,CW-PU/PPy的分散液的平均粒径由10.61nm增加至30.29nm,粒径分布系数由0.850下降至0.346。原位聚合过程中PPy能均匀包裹于CWPU胶粒表面,CWPU/PPy分散液胶粒呈球形结构,彼此间相互独立。实验结果亦表明,当Py浓度为20%、反应温度为40℃、反应时间为2h、n(FeCl3)/n(Py)=2.0时,CWPU/PPy复合薄膜的表面电阻率可达到20Ω.cm。     

磁性Fe3O4纳米颗粒的制备和磁性研究

讨论了一种制备磁性Fe3O4纳米颗粒的新方法，利用自行设计的反应容器，引入磁场和电场的相互作用，制得颗粒大小比较均一、分散性较好的Fe3O4纳米颗粒。通过改变反应时间、磁铁高度，得到了平均粒径为5～10nm的Fe3O4纳米颗粒，并对其进行磁特性测量。     

Synthesis,characterization, electrical and luminescence performance of novel copolymer of anthracene/pyrrole

A novel copolymer of anthracene/pyrrole at their different mole ratios has been prepared by facile oxidative coupling of anthracene and pyrrole using FeCl₃ as a catalyst in nitrobenzene/n-hexane. The prepared copolymers were analyzed by using FTIR, ¹HNMR, XRD, GPC and thermogravimetric techniques. The SEM photographs of copolymers exhibit uniform morphology and their crystallites arranged with random orientations. The temperature dependent electrical conductivity of copolymers was changed with respect to pyrrole concentration. The observed red shift in UV–Visible and excitation spectra of copolymers with pyrrole contents indicates the formation of large conjugation in their main chain. The fluorescence spectra of solid powder of copolymers was observed in the green region at maximum wavelength 518 nm with the addition of anthracene contents. However, the copolymer in the solution of concentrated sulphuric acid exhibited tuning of emission towards the red side. Furthermore, the copolymer excited at the maximum absorption wavelength (340 nm) of the pyrrole shows same emission band, indicating efficient energy transfer between pyrrole and anthracene units. Therefore, the present study shows improved thermal, electrical and optical properties of copolymers, which have practical applications in the fields of optoelectronic devices such as organic light emitting diode, conducting devices, solar cells etc.     

Synthesis and characterization of polysilicic acid nanoparticles/waterborne polyurethane nanocomposite

A novel nanocomposite that consists of polysilicic acid nanoparticles (PSA)/waterborne polyurethane (WPU) was prepared. The nano-size distribution of PSA particles were measured using the dynamic light scattering method. Nanocomposites were monitered and characterized by Fourier-Transform Infrared spectrophotometer (FT-IR). Si-mapping was used to elucidate the dispersion of silica in the nanocomposite. Morphological investigations revealed that PSA nanoparticles were well dispersed in waterborne polyurethane matrix on the nano-scale (100 nm). Thermal characteristics indicated that adding PSA increased the thermal degradation temperature by 43°C when the content of polysilicic acid nanoparticles was 5 wt%. Mechanical property tests demonstrated that adding polysilicic acid nanoparticles improved the tensile properties (by more than 100%), and reduced the wear index. Oxygen permeability tests showed that introducing the PSA nanoparticles increased the oxygen permeability of the nanocomposite.     

Synthesis and characterization of conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole

A new polythiophene containing a cholesteryl side chain in the -position was chemically polymerised in nitromethane/carbontetrachloride using FeCl₃ as the oxidizing agent. Polymerisation was also achieved by constant current electrolysis in dichloromethane. Subsequently, conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester (CM), PCM1 (obtained from chemical polymerisation method) and PCM4 (obtained from constant current electrolysis) with pyrrole were synthesized using p-toluene sulfonic acid and sodium dodecyl sulfate as the supporting electrolytes via constant potential electrolyses. Characterizations of the samples were performed by CV, FTIR, NMR, DSC, TGA and SEM analyses. Electrical conductivities were measured by the four-probe technique.     

叶酸受体靶向的聚乳酸共聚物的合成及性质

用氨基被保护的4-羟基-脯氨酸与L-丙交酯共聚合,得到含有活性氨基作为侧基的聚合物主链(PLLA-Hpr),通过DDC将叶酸与聚合物中的氨基反应,制得叶酸偶联的脯氨酸一乳酸共聚物(FA-PLLA-Hpr).采用1H-NMR、FT-IR确证了共聚物的结构,对比研究了共聚物的亲水性.结果表明成功地制备了叶酸受体靶向的聚乳酸共聚物.这种共聚物有望作为药物缓释领域的肿瘤靶向材料.     

Preparation and characterization of insulin nanoparticles employing chitosan and poly(methylmethacrylate/methylmethacrylic acid) copolymer

As most of polypeptides are marginally stable, a mild formulation procedure would be beneficial for the activities of these drugs. The objective of the present study was to develop a novel pH-sensitive nanoparticle system that was suitable for entrapment of hydrophilic insulin but without affecting its conformation. Chitosan was incorporated as a positively charged material, and one of the three poly(methylmethacrylate/methylmethacrylic acid) copolymers, consisting of Eudragit L100-55, L100, and S100, was used as a negatively charged polymer for preparation of three insulin nanoparticles, respectively. Three nanoparticles obtained were spherical. The mean diameters were in the range from 200 nm to 250 nm, and the entrapment efficiencies, from 50% to 70%. The surface analysis indicated that insulin was evenly distributed in the nanoparticles. Polymer ratio of chitosan to Eudragit was the factor which influenced the nanoparticles significantly. Characterization results showed that the electrostatic interactions existed, thus providing a mild formulation procedure which did not affect the chemical integrity and the conformation of insulin. In vitro release studies revealed that all three types of the nanoparticles exhibited a pH-dependant characteristic. The modeling data indicated that the release kinetics of insulin was nonlinear, and during the release process, the nanoparticles showed a polynomial swelling. On overall estimation, the insulin chitosan-Eudragit L100-55 nanoparticles may be better for the oral delivery. This new pH-sensitive nanoparticle formulation using chitosan and Eudragit L100-55 polymer may provide a useful approach for entrapment of hydrophilic polypeptides without affecting their conformation.     

Electrochemical synthesis of N-methyl and 3-methyl pyrrole perchlorate doped copolymer films

Electrochemical copolymerization of 3-methylpyrrole and N-methylpyrrole perchlorate doped has been carried out at two overpotentials and at different electrodeposition times in acetonitrile medium. A mixture of instantaneous and progressive nucleation mechanisms has been established from the current density-time transients. Doping/dedoping reversibility is deduced from the electrochemical study of copolymer films by cyclic voltammetry. Fourier Transform Infrared spectrum analysis shows that electropolymerization time has a great influence on the random monomers proportion in the copolymer obtained. Although the copolymer conductivity is in the range of the measured for poly 3-methylpyrrole and poly N-methylpyrrole obtained in similar conditions, it remains conductive for a much longer time than the homopolymers.     

Synthesis and characterization of PHV-block-mPEG diblock copolymer and its formation of amphiphilic nanoparticles for drug delivery

Despite the recent research interest in the field of nanoparticles delivery system, their structure modification and transport behavior of various hydrophobic drugs is poorly developed. In this article the synthesis of novel amphiphilic diblock copolymer poly([R]-3-hydroxyvalerate)-block-monomethoxy poly(ethylene glycol) (PHV-block-mPEG) was undertaken by modifying the structure of biodegradable and hydrophobic poly([R]-3-hydroxyvalerate) (PHV) with hydrophilic monomethoxy poly(ethylene glycol) (mPEG). The chemical combination of the two blocks was carried out in the melt using bis(2-ethylhexanoate) tin as transesterification catalyst. The synthesized product was characterized by gel permeation chromatography (GPC), 1H nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC) analysis. The block copolymer self-assembled into amphiphilic nanoparticles with a core of hydrophobic PHV and a shell of hydrophilic mPEG in aqueous solution. Characterization of the nanoparticles showed the formation of discrete, spherically shaped nanoparticles with mean particle size of 200 +/- 1 nm and zeta potential of -14 +/- 1 mV. A hydrophobic drug thymoquinone was efficiently incorporated into the core hydrophobic domain of the nanoparticles and its release kinetics was studied in vitro. The amphiphilic PEGylated nanoparticles showed biocompatibility when checked in neuronal hippocampal cells of prenatal rat. Our results suggest that the amphiphilic nanoparticles with core-shell structures are potentially useful to develop novel drug carriers.     

PBMA-b-PDMS-b-PBMA嵌段聚合物的合成与表征

以羟基封端的聚二甲基硅氧烷和α-溴代异丁酰溴为原料,制备了双官能度Br-PDMS-Br,并以此为大分子引发剂,CuCl和2,2’-联吡啶为催化剂,通过原子转移自由基聚合制备了聚甲基丙烯酸丁酯-聚二甲基硅氧烷-聚甲基丙烯酸丁酯(PBMA-b-PDMS-b-PBMA)三嵌段聚合物。利用傅里叶变换红外光谱仪(FT-IR)、核磁(1 H NMR)、凝胶渗透色谱分析仪(GPC)、热失重分析仪(TGA)、接触角测试仪、扫描电子显微镜(SEM)对三嵌段聚合物的结构及聚合反应进行了表征与测试。结果表明三嵌段聚合物具有较好的热稳定性、疏水性和微相分离。     

SiW9Ti3／硬脂酸固体脂质纳米粒的合成与表征

采用乳化和溶剂挥发的方法制备了基于SiW9Ti3的硬脂酸纳米粒，采用元素分析和红外光谱对其进行了表征．通过透射电镜和粒径分布仪确定了SiW9Ti3/硬脂酸固体脂质纳米粒的粒径在200-300nm之间．结果表明硬脂酸包封后的SiW9Ti3依然保持母体结构。