γ-(甲基丙烯酰氧)丙基倍半硅氧烷膜性能研究

为了研究γ-(甲基丙烯酰氧)丙基倍半硅氧烷膜(m-M-S)的性能,采用溶胶-凝胶法制备了TEOS改性的倍半硅氧烷膜材料(m-MST),利用扫描探针电镜、扫描电镜、差示扫描量热法、热重分析等技术对m-MST成膜材料的性能进行了表征.研究结果表明,此膜为有机-无机杂化纳米结构薄膜材料,波长345～2500nm范围内膜层的透光率为98%～99%;TEOS含量在20%时,薄膜体系的机械性能和耐腐蚀性性能最佳.     

甲基丙烯酸甲酯-顺丁烯二酸酐共聚物/SiO2杂化材料的制备与性能

用γ-氨丙基三乙氧基硅烷(APTEOS)为交联剂，以甲基丙烯酸甲膏(MMA)、顺丁烯二酸酐(MAH)和四乙氧基硅(TEOS)为原料，通过自由基溶液聚合和溶胶-凝胶过程制得了两相间以共价键结合的透明MMA-MAH共聚物／SiO2有机-无机杂化材料。通过FT-IR分析证实了材料有机相与无机相之间是以共价键结合的．随着无机相含量的增加，材料热性能呈明显上升趋势．复合材料可见光透过率在75％左右，当SiO2含量超过一定值后，可见光透过率逐渐降低。研究结果初步表明，在复合材料中有机相和无机相是纳米复合的。     

P(AMPS+AM)/SiO2高吸水性杂化材料的制备及性能

研究了以2-丙烯酰胺基-2-甲基丙磺酸（AMPS）和丙烯酰胺（AM）共聚物为有机相,通过正硅酸乙酯（TEOS）引入SiO2无机相,采用溶胶-凝胶法制得了P（AMPS＋AM）/SiO2高吸水性杂化材料,并着重研究了不同用量的TEOS对材料结构和性能的影响.采用傅立叶红外（FT-IR）、扫描电镜（SEM）等检测方法对材料进行了表征,同时对材料的透光性、吸液性能、热稳定性等进行了评价.结果表明,TEOS用量为5%（相对单体质量百分含量）左右制得的高吸水性杂化材料较为理想.     

低收缩块状PMMA/SiO_2杂化材料制备及性能表征

以甲基丙烯酸甲酯(MMA)、正硅酸乙酯(TEOS)和硅烷偶联剂(MPMS)为原料,采用溶胶-凝胶法制备出低收缩、具有良好光学性能的PMMA/SiO2杂化材料。通过透射电子显微镜、差热分析、红外吸收光谱和紫外光-可见分光光度计表征了杂化材料的微观形貌、热性能和透明性。结果表明材料的网络结构相对比较均匀,在可见光波长范围内材料均一性好;有机相和无机相之间是通过共价键相互连接的,没有出现有机相、无机相分离现象;杂化材料的透光率约90%。     

新型PU-DR19-SiO2纳米复合材料的制备和表征

利用溶胶-凝胶法将硅烷染料、含硅氧烷的非线性聚氨酯与TEOS共水解-缩合首先制备了新型PU-DR19-SiO2纳米复合材料,并用IR、SEM、TEM、UV-vis和DSC-TGA对其结构和性能进行了表征.结果显示:材料中有机相与无机相以共价键相连,没有发生相分离,且其中非线性较好的DR19生色团含量和材料的Tg都较纯NLO/PU有显著增加,可以用来制备性能优良的二阶非线性光学器件.     

环氧基倍半硅氧烷杂化膜的摩擦性能研究

采用溶胶-凝胶法,将不同含量的正硅酸乙酯(TEOS)与r-缩水甘油醚基丙基三甲基硅烷(GPMS)共水解缩合,所得终产物为有机-无机纳米杂化材料,用浸渍法使其在玻璃基体上成膜,并利用扫描探针电镜(SPM)对膜的形貌进行了表征.通过MTS Nano Indenter XP纳米压痕仪研究了TEOS的含量对杂化体系摩擦性能的影响.结果表明,环氧基倍半硅氧烷杂化膜在TEOS含量为5%时表面粗糙度最小、弹性恢复能力最大,TEOS含量为10%时摩擦系数最小.     

PBMA-SiO2杂化纤维的制备及表征

以正硅酸乙酯(TEOS)和聚甲基丙烯酸丁酯(PBMA)为前躯体,乙烯基三乙氧基硅烷(VTEOS)为偶联剂,通过溶胶-凝胶法制备了SiO2纤维和PBMA/SiO2杂化纤维,并使用IR、SEM、TGA等进行了结构与性能表征,研究了溶胶的杂化反应机理、成纤性能.结果表明:硅烷偶联剂的引入使得PBMA-SiO2杂化纤维均匀性较好,纤维中有机相与无机相之间通过化学键连接,实现了有机-无机组分的充分贯穿;其耐热性能优于纯PBMA.     

正硅酸乙酯改性的GPMS有机-无机材料研究

为了考察正硅酸乙酯(TEOS)对材料性能的影响，采用溶胶-凝胶法制备了TEOS改性的γ-环氧丙基醚丙基三甲氧基硅烷(GPMs)有机-无机杂化材料，并用浸渍法使其在玻璃基体上成膜，利用红外光谱、核磁共振谱和原子力显微镜对GPMS-TEOS杂化材料的结构进行了表征，采用差热分析仪、纳米硬度测试仪和扫描分光光度计等对其物化性能进行了测试．结果表明，制得的材料具有纳米级倍半硅氧烷结构，TEOS的含量对杂化体系性能有较大影响；当TEOS质量分数为15％～20％时，杂化体系的热稳定性、硬度和模量等性能最佳，并且具有良好的透光性。     

有机-无机杂化纳米复合材料合成及性能测试

采用溶胶-凝胶法,以甲基三乙氧基硅烷(MTEOS)和正硅酸乙酯(TEOS)及纳米氧化硅为原料,成功制备了有机-无机杂化纳米复合材料及涂层.以X射线衍射(XRD)、富立叶红外光谱(FTIR)、扫描电子显微镜(SEM)和原子力显微镜(AFM)等手段研究了杂化材料的工艺与结构及性能的关系,并对涂覆于铝合金基体上的纳米复合材料涂层的防腐蚀性能进行了实验检测.结果表明,有机-无机杂化纳米复合材料涂层具有优良的抗腐蚀性能.     

有机蒙脱土/丁腈橡胶-聚氯乙烯隔声复合材料的制备及性能

轻质隔声材料一直是隔声功能材料的研究热点.本研究以NBR-PVC为基料,通过纳米有机蒙脱土(OMMT)填充改性制备了有机蒙脱土/丁腈橡胶-聚氯乙烯隔声材料,并探讨了纳米有机蒙脱土添加量对材料面密度、力学性能、阻尼性能和隔声性能的影响.实验结果表明,当OMMT质量含量为3.73%时,OMMT/NBR-PVC复合材料的弹性模量、拉伸强度、断裂伸长率及阻尼性能综合最佳,其隔声指数可达32.6 dB.     

Nanosize stabilization of cubic and tetragonal phases in reactive plasma synthesized zirconia powders

Pure zirconium oxide powders with particle size 2–33 nm are synthesized by reactive plasma processing. Transmission electron microscopy investigation of these particles revealed size dependent behavior for their phase stabilization. The monoclinic phase is found to be stable when particle size is ≥20 nm; Tetragonal is found to be stabilized in the range of 7–20 nm and as the particle size decreases to 6 nm and less, the cubic phase is stabilized.     

Characterization of nano-crystalline ZrO2 synthesized via reactive plasma processing

Nano-crystalline ZrO₂ powder has been synthesized via reactive plasma processing. The synthesized ZrO₂ powders were characterized by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM) and FTIR spectroscopy. The synthesized powder consists of a mixture of tetragonal and monoclinic phases of zirconia. Average crystallite size calculated from the XRD pattern shows that particles with crystallite size 20 nm or less than 20 nm are in tetragonal phase, whereas particles greater than 20 nm are in the monoclinic phase. TEM results show that particles have spherical morphology with maximum percentage of particles distributed in a narrow size from about 15 nm to 30 nm.     

Generalized Access to Mesoporous Inorganic Particles and Hollow Spheres from Multicomponent Polymer Blends

Mesoporous inorganic particles and hollow spheres are of increasing interest for a broad range of applications, but synthesis approaches are typically material specific, complex, or lack control over desired structures. Here it is reported how combining mesoscale block copolymer (BCP) directed inorganic materials self‐assembly and macroscale spinodal decomposition can be employed in multicomponent BCP/hydrophilic inorganic precursor blends with homopolymers to prepare mesoporous inorganic particles with controlled meso‐ and macrostructures. The homogeneous multicomponent blend solution undergoes dual phase separation upon solvent evaporation. Microphase‐separated (BCP/inorganic precursor)‐domains are confined within the macrophase‐separated majority homopolymer matrix, being self‐organized toward particle shapes that minimize the total interfacial area/energy. The pore orientation and particle shape (solid spheres, oblate ellipsoids, hollow spheres) are tailored by changing the kind of homopolymer matrix and associated enthalpic interactions. Furthermore, the sizes of particle and hollow inner cavity are tailored by changing the relative amount of homopolymer matrix and the rates of solvent evaporation. Pyrolysis yields discrete mesoporous inorganic particles and hollow spheres. The present approach enables a high degree of control over pore structure, orientation, and size (15–44 nm), particle shape, particle size (0.6–3 µm), inner cavity size (120–700 nm), and chemical composition (e.g., aluminosilicates, carbon, and metal oxides).     

块状PMMA/TiO_2有机-无机杂化材料的制备与表征

以钛酸丁酯为前驱体,在亚化学计量的水中水解,以硅烷偶联剂(MPMS)和丙烯酸为改性剂,采用溶胶-凝胶法制得均一、稳定的淡黄色二氧化钛溶胶,透射电镜分析粒径约20～30nm;在溶胶中加入甲基丙烯酸甲酯(MMA)和偶氮二异丁腈(AIBN),采用热固化方法制得淡黄色透明的PMMA/TiO2块体材料;通过TEM、FT-IR、DSC和TG表征杂化材料的微观结构和热性能.研究表明,杂化材料中PMMA和TiO2是以共价键连接的,TiO2均匀分散在PMMA中,两相之间没有明显的相分离现象;当w(TiO2)=20%时,杂化材料的玻璃化转变温度为175℃,比纯PMMA提高了约70℃,分解温度为300℃,比纯PMMA提高了120℃.     

Hybrid analogs for the production of porous calcium phosphate scaffolds

A polymer–inorganic sol mixture has been used to develop interconnected and highly porous calcium phosphate networks. The inorganic sol was developed by reacting triethyl phosphite and calcium nitrate. The sol was directly added to an aqueous solution of PVA with molecular weights between 40,500 and 155,000 g/mol. This mixture was electrospun at a voltage of 20 kV to produce fibers, whose diameter was less than 1 μm. This electrospun structure was calcined at 600 °C obtain to a highly interconnected sub-micron fibrous network (fiber size ∼ 200 nm) of calcium phosphate. The crystal size is on the order of 30 nm. Micropores could be introduced in each of the fibers by controlling the polymer molecular weight and the sol volume fraction. Such structures can have many potential uses in the repair and treatment of bone defects and in drug delivery.     

纳米晶Ba_（1－x）Pb_xTiO_3的合成与表征

以醋酸铅、硬脂酸钡和钛酸丁酯为原料，用硬脂酸凝胶法（ＳＡＧ）合成了粒度均匀、粒径１０－２０ｎｍ的Ｂａ（１－ｘ）ＰｂｘＴｉＯ３纳米晶粉末．利用红外光谱（ＩＲ）、热重（ＴＧ）和差热分析（ＤＴＡ）研究了纳米晶粉末的合成过程．用ＴＥＭ、ＸＲＤ观察和研究纳米晶的形貌及晶体结构，并用发射光谱测定样品的纯度．     

Fabrication of organic nanocrystals for electronics and photonics

We have presented a simple technique for the fabrication of nanocrystals of organic molecules and polymers and have shown that it is possible, using the liquid-phase technique, to fabricate organic nanocrystals ranging in size from 10 nm to 1 μm by manipulating the preparative conditions. In particular, nanocrystals of poly(4-BCMU) ranging from 20 nm to 350 nm were prepared by controlling the preparation conditions. The main advantages of the liquid-phase technique are the practicality and suitability of the technique for a wide range of materials. The fabrication of organic nanocrystals, though at a very early stage, seems a promising approach for producing low-dimensional organic materials and, like inorganic nanocrystals, another important objective for future study would be to incorporate organic nanocrystals into a variety of inorganic and organic media. It is hoped that extensive work will be done on organic nanocrystals to evaluate their potential for electronics and photonics.     

Inhibitory activity of gold and silica nanospheres to vascular endothelial growth factor （VEGF）-mediated angiogenesis is determined by their sizes

Nanoparticles can be involved in biological activities such as apoptosis, angiogenesis, and oxidative stress by themselves. In particular, inorganic nanoparticles such as gold and silica nanoparticles are known to inhibit vascular endothelial growth factor （VEGF）-mediated pathological angiogenesis. In this study, we show that anti-angiogenic effect of inorganic nanospheres is determined by their sizes. We demonstrate that 20 nm size gold and silica nanospheres suppress VEGF-induced activation of VEGF receptor-2, in vitro angiogenesis, and in vivo pathological angiogenesis more efficiently than their 100 nm size counterparts. Our results suggest that modulation of the size of gold and silica nanospheres determines their inhibitory activity to VEGF-mediated angiogenesis.     

纳米羟基磷灰石丝素蛋白仿生矿化材料的制备研究

以Ca(NO₃)₂与Na₃PO₄为无机相的前驱体,将丝素蛋白直接溶于Ca(NO₃)₂溶液中,不经过脱盐处理,直接滴入Na₃PO₄溶液中反应,在37℃下丝素蛋白和羟基磷灰石晶体之间相互作用,仿生合成了纳米羟基磷灰石(n-HA)丝素蛋白(SF)生物矿化材料.用FTIR、XRD、XPS和SEM进行表征.结果表明,羟基磷灰石和丝素蛋白两相间具有较强的化学键合,矿化材料中无机相包含少量碳酸根,为缺钙类骨羟基磷灰石并且呈现一定的长轴取向性,说明丝素蛋白大分子对羟基磷灰石晶体的成核和生长起着模板和调控作用.矿化物颗粒尺寸在50~200nm之间,其抗压强度为32.21MPa,可作为非承重部位骨组织缺损修复材料.     

Preparation of barium titanate nanocube particles by solvothermal method and their characterization

Barium titanate (BaTiO₃) nanocube particles below 20 nm were prepared by solvothermal method. A selection of organic solvent and inorganic materials of Ba and Ti sources was most important for the preparation of nanocubes. A nucleation and particle growth of BaTiO₃ nanoparticles led to a formation of the BaTiO₃ nanocubes with a size of 10–15 nm at temperatures above 200 °C.