Polypropylene non-woven supported fibronectin molecular imprinted calcium alginate/polyacrylamide hydrogel film for cell adhesion

Fibronectin (FN) imprinted polypropylene (PP) non-woven supported calcium alginate/polyacrylamide hydrogel film (PP-s-CA/PAM MIP) was prepared using non-woven PP fiber as matrix, FN as template molecule, sodium alginate (SA) and acrylamide (AM) as functional monomers, via UV radiation-reduced polymerization. The PP-s-CA/PAM MIP exhibited an obvious improvement in terms of adsorption capacity for FN compared with non-imprinted polymer (NIP). The PP-s-CA/PAM MIP was successfully used for the culture of mouse fibroblast cells (L929) and the results showed that PP-s-CA/PAM MIP exhibited better cell adherence performance than the NIP did.     

Polyacrylamide/reduced graphene oxide-Ag nanocomposite as highly efficient antibacterial transparent film

In this study, preparation and characterization of polyacrylamide/reduced graphene oxide-Ag (PAM/rGO-Ag) nanocomposites as a new nanocomposite film were investigated. First, PAM/GO nanocomposite was synthesized by in situ polymerization strategy. Afterward, highly stable and uniformly distributed silver nanoparticles (Ag NPs) have been obtained with PAM/GO nanocomposite as nanoreactors via in situ reduction of silver nitrate (AgNO₃) using sodium borohydride (NaBH₄) as reducing agent. In addition, the prepared PAM/rGO-Ag nanocomposite was thermally annealed in order to achieve high-performance nanocomposite film with antimicrobial activities. The prepared nanocomposite was characterized by XRD, FT-IR, SEM, TEM and TGA. The obtained results demonstrate that the silver nanoparticles were well decorated and dispersed on the graphene oxide nanosheets. In fact, the GO nanosheets and polyacrylamide chains act as a support and stabilize the Ag nanoparticles. Moreover, antimicrobial activities of the films were also examined, and the films containing well-dispersed and stabilized Ag nanoparticles showed outstanding antibacterial activity.     

Synthesis, photoluminescence, and adsorption of CdS/dendrimer nanocomposites

CdS/dendrimer nanocomposites can be synthesized from methanolic Cd(2+) and S(2-) with amine-terminated polyamidoamine dendrimers of generation 8 (G8NH(2)) as stabilizers. By controlling the preparation conditions, nanoparticles with diameters < or = 2 nm can be obtained with a narrow size distribution. They show blue photoluminescence at approximately 450 nm. We studied the effects of various additives on the photoluminescence and elucidated its mechanism. Stable aggregates of two to three G8NH(2) molecules with several CdS nanoparticles form; the particles are located at the surface of the G8NH(2) molecules. The adsorption of the CdS/G8NH(2) nanocomposites on flat substrate surfaces is determined by the substrate chemistry. The hydrophilic nature of G8NH(2) results in weak affinity to graphite but strong affinity to hydroxy-terminated substrates such as mica, oxidized silicon wafers, and carboxylate-terminated monolayers. Patterning of nanocomposites on these hydrophilic substrates is achieved by the microcontact printing method. We propose to use only one molecule, a large dendrimer, to control the nanoparticle formation and also the immobilization of the synthesized nanoparticle/dendrimer composites.     

Luminescent and magnetic Fe3O4/Py/PAM nanocomposites for the chromium(VI) determination

A novel luminescent and magnetic Fe(3)O(4)/pyrene/polyacrylamide (Fe(3)O(4)/Py/PAM) nanocomposite has been prepared under ultrasonic radiation. This magnetic nanocomposite combined with pyrene would lead to a special functional magnetic luminescent composite that enjoys both the advantages of magnetic nanoparticles of Fe(3)O(4) and fluorescence nanoparticles of pyrene. Taking advantage of the magnetic property of Fe(3)O(4) nanocomposites, we can separate Fe(3)O(4)/Py/PAM nanocomposites from solution easily just by using a permanent magnet. Based on the fluorescence quenching of Fe(3)O(4)/Py/PAM nanocomposites by Cr(VI), a method for the selective determination of Cr(VI), without separation of Cr(III) in water, was developed. Under optimal experimental conditions, a limit of detection of 0.01 microg mL(-1) was achieved. The calibration curve was linear over the concentration range of 0.1-14.0 microg mL(-1) with a correlation coefficient of 0.9975. The proposed method has been applied to the selective quantification of Cr(VI) in synthetic samples and wastewater samples with the satisfactory results.     

荧光磁性双功能树状分子微球的制备与表征

采用化学共沉淀法, 以FeCl₃·6H₂O和FeSO₄·7H₂O为原料制备了磁性Fe₃O₄纳米颗粒, 采用树状大分子对其进行修饰, 然后通过树状大分子具有的大量空腔及末端丰富的氨基, 经吸附、 键合, 与大量巯基乙酸修饰的CdSe/CdS量子点连接, 得到三代具有荧光磁性双功能的树状分子微球, 并对其进行结构表征与性能测试. 结果表明: 三代复合后的微球的平均粒径分别为15, 34和49 nm; 一代荧光磁性微球的发光性能最佳, 其量子产率达24.1%; 零代荧光磁性微球磁性能最优, 其饱和磁化强度为15.96 A·m²/kg. 这种具有荧光和磁性的双功能纳米复合微粒有望在免疫检测、 靶向治疗、 荧光追踪和磁性分离等方面得到广泛应用.     

The influence of DMSO on the formation and photoelectrochemical properties of CdS thin films by electrodeposition method

The homodispersed CdS nanoparticles were prepared on Sn-doped indium oxide substrates (ITO) to form smooth and uniform CdS thin films by electrodeposition method from a dimethyl sulfoxide (DMSO) solution containing cadmium chloride and sulfur. The structure and morphologies of samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The results indicate that DMSO played an important role in formation of CdS nanofilms by affecting the nucleation and growth of the CdS nanoparticles. So, a DMSO-assisted growth process was proposed as a plausible mechanism for the formation of smooth and uniform CdS nanofilms. According to the photoelectrochemical test, the CdS thin film prepared in 30 % DMSO + 70 % H₂O system exhibited maximum photocurrent and open circuit potentials. This is because the deposited CdS nanoparticles had better dispersity on ITO, which facilitated the propagation and kinetic separation of photogenerated charges.     

Homogeneously distributed CdS nanoparticles in nafion membranes: preparation, characterization, and photocatalytic properties

Stable crystalline CdS nanoparticles were synthesized in Nafion ionomer membranes by using thioacetamide (TAA) as a nonionic precursor. Unlike the ionic precursors such as Na(2)S, TAA could diffuse into the cationic-exchangeable ionomer membranes much more uniformly. This led to the formation of homogeneously distributed CdS nanoparticles in the Nafion membranes, which was confirmed by elemental mapping with energy-dispersive X-ray (EDAX) analysis. Results from the characterizations on the physical properties, the chemical stability, and the photocatalytic properties of these CdS nanoparticles embedded in Nafion membranes are presented and discussed. The parallel data from the CdS nanoparticles in Nafion membranes prepared from the ionic Na(2)S precursor are also shown for comparison.     

肌红蛋白在Nafion/Fe3O4- CdTe/CdS量子点复合膜内的直接电化学及其应用于H2O2的生物传感

利用磁性纳米Fe3O4和CdTe/CdS量子点结合Nafion的良好成膜性,将肌红蛋白(Mb)固定在玻碳 电极表面制备成Nafion/Fe3O4 - CdTe/CdS - Mb/GCE修饰电极.在pH 7.0的0.1 mol/L磷酸盐缓冲溶液 (PBS)中,固定在膜内的Mb表现出良好的直接电化学性质,在-0.351...     

Thin films composed of irregular micro-block arrays of closely packed CdS nanoparticles for enhanced photoelectrochemical performance

CdS is a very important semiconductor, and various micro-/nano-structured forms of CdS have been fabricated with the aim of improving its photoelectrochemical performance. We report here for the first time the preparation of a CdS film consisting of irregular micro-block arrays of closely packed CdS nanoparticles. It performs outstandingly well as a photoanode because it possesses the advantages of both arrays and nanoparticles. This CdS film is prepared simply by a combination of reaction and assembly at the gas/liquid interface (RAG/L) with successive ionic layer adsorption and reaction (SILAR), requiring no templates or expensive equipment. In this approach, the nanopores in the film of loosely aggregated CdS nanoparticles produced by RAG/L are filled by CdS nanoparticles via SILAR, forming a compact CdS film. Network micro-cracks form in the compact CdS film due to calcination caused by differential thermal expansion compared with the substrate, and these cut the CdS film into irregular micro-block arrays. This micro-/nano-structure in the prepared CdS film improves its capacity for visible light absorption, facilitates the generation/separation of excited charges, and enhances mass transfer. In an alkaline solution of methanol, the prepared CdS film exhibits the highest saturation photocurrent density (6.5 mA cm^− 2) ever reported on CdS-based photoanodes under visible light illumination.     

Chemical synthesis and optical properties of CdS–poly(lactic acid) nanocomposites and their transparent fluorescent films

This paper describes the first synthesis of cadmium sulfide (CdS)-poly(lactic acid) (PLA) nanocomposites and their transparent fluorescent films by covalently grafting PLA onto the surfaces of CdS nanocrystals (NCs). Synthesis of the nanocomposites involved two steps. Lactic acid (LA)-capped CdS NCs were first prepared by reacting cadmium chloride (CdCl₂) with sodium sulfide (Na₂S) using LA as the organic ligand in H₂O/N,N-dimethylformamide (DMF) solution. CdS–PLA nanocomposites were then formed by in situ ring-opening polymerization of lactide on the surface of modified CdS NCs. We also demonstrated herein the fabrication of the transparent fluorescent films of CdS–PLA nanocomposites by blending as-prepared nanocomposites with high-molecular-weight PLA. The as-prepared CdS NCs and their nanocomposites were studied by transmission electron microscopic imaging, thermogravimetric analyses, and spectroscopic measurements (ultraviolet–visible absorption and photoluminescence). The results revealed that the CdS–polymer nanocomposites exhibited good optical properties in terms of their photoluminescence and transparency.     

新型CdS/TiO2纳米复合材料的制备及其可见光催化性能研究

采用浸渍法和水热法相结合制备了新型的CdS/TiO₂纳米复合材料,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、UV-Vis吸收光谱(UV-VIS)、电子自旋共振谱(ESR)等对样品进行了表征,XRD、TEM表明所制备的新型CdS/TiO₂粒径小、分散均匀,TiO₂以锐钛矿型存在,CdS以高分散的立方相和六方相存在,对比直接法制备的CdS/TiO₂,新型的CdS/TiO₂对活性艳红X-3B具有明显提高的可见光催化活性;大量的束缚单电子氧空位及电子之间强相互作用是新型CdS/TiO₂可见光催化活性提高的主要原因.     

PAMAM树形分子与Cd2＋的配位作用研究及CdS/PAMAM纳米复合材料的制备与表征

CdS半导体纳米簇具有独特的光、电性能, 如何制备均匀分散的、能够稳定存在的CdS纳米簇是目前的研究热点之一. 以聚酰胺-胺(PAMAM)树形分子为模板, 原位合成了CdS纳米簇. 首先用UV-Vis分光光度法研究了与树形分子的配位机理, 得出G4.5和G5.0的平均饱和配位数分别为16和34, 并发现在G4.5PAMAM树形分子中Cd^2＋主要与最外层叔胺基配位, 在G5.0PAMAM树形分子中Cd^2＋主要与最外层伯胺基配位. 酯端基的G4.5的模板作用要明显优于胺端基的G5.0. 通过改变Cd^2＋与G4.5树形分子的摩尔比可以得到不同粒径的CdS纳米簇. 溶液的pH值对CdS纳米簇影响很大, pH在7.0左右制备的CdS纳米簇粒径小而均匀, 且溶液稳定性高. 用UV-Vis分光光度计和TEM对CdS纳米簇的大小和形貌进行了表征. 结果表明TEM观测CdS纳米簇的粒径要大于用Brus公式的估算值.     

电沉积法制备介孔TiO_2/CdS薄膜光电极

采用阴极恒电位沉积法,在介孔TiO2薄膜上制备了介孔TiO2/CdS薄膜光电极,用XRD,SEM,Raman,SPS和UV-Vis等多种手段对薄膜电极进行了表征.结果表明,CdS成功沉积到介孔TiO2的表面和孔道内,形成了异质结结构.通过光电流作用谱考察了该复合体薄膜电极的光电性能,结果表明,与单纯的介孔TiO2薄膜相比,其光电转换效率显著提高,这是由于CdS具有吸收可见光的特性以及CdS与介孔TiO2形成异质结从而使得光生载流子更容易分离的结果.     

Liquid-crystalline polymer composites with CdS nanorods: structure and optical properties

We report on the structure, uniaxial orientation, and photoluminescent properties of CdS nanorods that form stable nanocomposites with smectic C hydrogen-bonded polymers from the family of poly(4-(n-acryloyloxyalkoxy)benzoic acids. TEM analysis of microtomed films of nanocomposites reveals that CdS nanorods form small domains that are homogeneously distributed in the LC polymer matrix. They undergo long-range orientation with the formation of one-dimensional aggregates of rods when the composite films are uniaxially deformed. The Stokes photoluminescence was observed from CdS NRs/LC polymer composites with emission peak located almost at the same wavelength as that of NRs solution in heptane. An anti-Stokes photoluminescence (ASPL) in polymer nanocomposites was found under the excitation below the nanoparticles ground state. The mechanism of ASPL was interpreted in terms of thermally populated states that are involved in the excitation process. These nanocomposites represent an unusual material in which the optical properties of anisotropic semiconductor nanostructures can be controlled by mechanical deformation of liquid-crystalline matrix.     

合成聚丙酰胺-硫属半导体复合纳米材料的新技术

在水溶液体系中采用同步聚合-水解技术（Simultaneous Polymerization-Hydrolysis）制备聚丙烯酰胺-半导体纳米复合材料。该SPH技术是基于丙烯酰胺单体的聚合和MS(M=Cd,Pb,Zn)纳米粒子的形成同步发生,使生成的半导体纳米粒子可均匀分散在聚丙烯酰胺基质中。该技术还为制备其它有机聚合物-金属硫化物纳米复合物提供了一种新途径。     

Templated Synthesis of CdS/PAN Composite Nanowires under Ambient Conditions

CdS/PAN (polyacrylonitrile) composite nanowires were prepared by templated synthesis under ambient conditions, using a 4 : 1 (v/v) distilled water-isopropyl alcohol solvent mixture and Na(2)S(2)O(3) as sulfur source. Transmission electron microscopy images showed typical CdS/PAN nanowires with diameters less than 6 nm and lengths from 200 nm to 1 μm. CdS/PAN nanowires were also characterized by FT-infrared spectra (FTIR), X-ray powder diffraction (XRD) patterns, and UV-vis spectra. It is found that the feed mole ratio of CdCl(2) to AN exerts a significant influence on the formation and morphology of CdS/PAN nanowires. In addition, possible mechanism of the reactive process was presented. Copyright 2000 Academic Press.     

Fe_3O_4/CdTe/聚氨酯纳米复合物的制备及其性能研究

由共沉淀法和Stober法制备了伯胺基功能化SiO2稳定的Fe3O4磁性纳米粒子Fe3O4@SiO2-NH2;Fe3O4@SiO2-NH2与二异氰酸酯及咪唑阳离子二醇、聚乙二醇的反应使其表面形成阳离子型聚氨酯稳定层;通过阳离子型聚氨酯与CdTe量子点表面修饰的巯基乙酸间的电荷相互作用,制备得到了Fe3O4/CdTe/聚氨酯纳米复合物.用X射线衍射(XRD)、红外吸收光谱(FTIR)、热重分析(TGA)、透射电子显微镜(TEM)、磁强计(VSM)、紫外吸收光谱(UV)、荧光发射光谱(PL)表征了该纳米复合物的结构与性能.结果表明,CdTe量子点均匀地分散在Fe3O4@SiO2磁性纳米粒子周围,所得纳米复合物在溶剂中分散均匀,不团聚,且具有超顺磁性,并保持了CdTe量子点的荧光性能.     

导电聚苯胺与磁性CoFe2O4纳米复合物的制备与表征

在利用HNO3酸化处理CoFe2O4磁性纳米粒子使其表面离子化、分散性得到改善的基础上, 采用原位聚合法制备了具有电磁功能的聚苯胺/CoFe2O4 (PANI/CoFe2O4)纳米复合物. 借助TEM, XRD, FT-IR, TG, 四探针电导率仪、VSM(振动样品磁强计)等分析手段研究了复合物的形貌、结构、热稳定性及电磁性能. 结果表明, 处理过的CoFe2O4磁性纳米粒子可形成分散均匀的PANI/CoFe2O4纳米复合物, CoFe2O4以25 nm左右的粒子分散于聚苯胺基体中; PANI与CoFe2O4之间存在化学键合作用, 正是这种作用使复合物热稳定性得以提高; 复合物同时具有导电性和磁性能, 且随CoFe2O4含量变化而变化.     

CdS/石墨烯纳米复合物的可见光催化效率和抗光腐蚀行为

制备了一系列CdS纳米晶/石墨烯(CdS/GR)复合物,并在可见光照条件下评价了其光催化降解亚甲基蓝的光催化效率和抗光腐蚀行为. 研究表明,石墨烯的引入加速了CdS纳米晶(NCs)光生电子的迁移速率,抑制了其光生电子-空穴的复合,有效改善了其光催化降解有机污染物的性能. CdS/GR复合物中的石墨烯含量显著影响其光催化效率,其中石墨烯含量为4.6%的光催化剂效率最高,其光电流是CdS NCs的2.3倍. 利用光电化学和X射线衍射技术进一步证实,石墨烯的引入抑制了CdS NCs光腐蚀的发生,提高了CdS/GR复合物的光催化稳定性.     

CdS超薄片层包覆TiO2中空结构复合材料的形成和应用

本实验以钛酸四丁酯为钛源,醋酸镉为镉源,利用静电纺丝的方法制备了直径~250 nm的电纺丝纳米纤维。通过高温煅烧和硫化钠溶液进行水热处理,得到CdS超薄片层包覆TiO₂中空结构的纳米纤维。推测该复合结构形貌的形成过程为:在Ti/Cd(摩尔比)为1:1和2:1时,由于CdO的含量较高,反应过程中CdO溶解,并与反应溶液中的S^2-形成CdS超薄片层生长在纤维的外表面,剩余的TiO₂纳米粒子聚集形成中空的纳米管状结构;而Ti/Cd(摩尔比)为4:1和8:1时,由于溶解的CdO较少不足以形成TiO₂纳米管,同时,生成的CdS也不足以完全包覆TiO₂纳米纤维形成非管状结构。当Ti/Cd为1:1时,TiO₂@CdS复合材料具有最好的产氢活性。在300 W氙灯光照条件下和加UVCUT-420 nm滤光片下,50 mg催化剂产氢速率分别为19.7 μmol/h和3.4 μmol/h,这主要是由于所得到的复合结构中TiO₂为非晶材料。进一步在惰性气氛下煅烧,也很难将TiO₂晶化。