类蛋结构的可磁分离光催化剂纳米球的制备及催化性能

通过反胶束和静电自组装方法制备了一种类蛋结构的可磁分离光催化剂纳米材料SiO₂@NiFe₂O₄@TiO₂(TSN), 这种光催化剂对甲基橙废水有较好的降解效果, 并显示出了超顺磁性, 通过外加磁场方便地实现催化剂在水中的分离与回收. 该光催化剂纳米球的X射线衍射, TEM和FTIR结果表明, 铁酸镍纳米粒子被包裹在SiO₂内, 形成SiO₂@NiFe₂O₄(SN)纳米球载体, 纳米TiO₂颗粒组装在SN表面, 形成TiO₂光催化壳层. 利用甲基橙的降解考察了光催化剂纳米球的活性, 结果表明, 在NiFe₂O₄和TiO₂之间包覆一层无定形的SiO₂可以显著提高光催化剂纳米球TSN的催化活性.     

Synthesis and Characterization of Magnetic TiO2/SiO2/NiFe2O4 Composite Photocatalysts

Magnetic TiO2/SiO2/NiFe2O4 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route.The prepared composite particles were characterized with X-ray diffraction(XRD),transmission electron microscopy(TEM),high resolution transmission electron microscopy(HRTEM),scanning electron microscopy(SEM),ultraviolet-visible(UV-Vis) spectroscopy and vibrating sample magnetometer(VSM).The results show that the obtained TiO2/SiO2/NiFe2O4 composite particles were composed...     

PS/TiO2复合纳米微球的制备和结构表征

无机纳米微粒具有特殊的物理化学性能 ,近年来在摩擦学领域中受到越来越多的重视 .由于无机纳米微粒难以分散于润滑基础油中 ,故其作为润滑材料主要用作聚合物填料和润滑脂添加剂 .为了改善其在基础油中的分散性 ,需要对无机纳米微粒进行表面改性 ,制备成有机无机复合纳米微粒 ,从而使它们能够用作润滑油添加剂 .目前有机小分子表面修饰无机纳米微粒的摩擦学性能已有报导 [1－ 3],但是聚合物修饰无机纳米微粒的研究较少 ,并且大多是采用高分子（如 PVK,PVA等）直接包埋的方法 ,用这种方法制得的微粒 ,粒径差别较大,性能不太稳定 .　　本…     

Application of liquid phase deposited titania nanoparticles on silica spheres to phosphopeptide enrichment and high performance liquid chromatography packings

A novel core-shell composite (SiO(2)-nLPD), consisting of micrometer-sized silica spheres as a core and nanometer titania particles as a surface coating, was prepared by liquid phase deposition (LPD). Here, we show the resulting core-shell composite to have better efficient and selective enrichment for mono- and multi-phosphopeptides than commercially available TiO(2) spheres without any enhancer. The material exhibited favorable characteristics for HPLC, which include narrow pore size distribution, high surface area and pore volume. We also show that the core-shell composite can efficiently separate adenosine phosphate compounds due to the Lewis acid-base interaction between titania and phosphate group when used as HPLC packings. After coating the silica sphere with titania by LPD, the silanol of silica spheres will be shielded and that the stationary phase, C(18) bonded SiO(2)-3LPD, could be used under extreme pH condition.     

TiO_2/SiO_2纳米薄膜的光催化活性和亲水性

通过 sol-gel工艺在钠钙玻璃表面制备了均匀透明的 TiO2/SiO2复合纳米薄膜 .实验结果表明 : 当 SiO2添加量较高时 , TiO2/SiO2复合纳米薄膜的光催化活性明显降低 ;当 SiO2添加量较低时 ,TiO2/SiO2复合薄膜的光催化活性无明显变化 .在 TiO2薄膜中添加 SiO2,可以抑制薄膜中 TiO2晶粒的长大 ,同时薄膜表面的羟基含量增加 , 水在复合薄膜表面的润湿角下降 , 亲水能力增强 .当 SiO2含量为 10％－ 20％（摩尔分数）时获得了润湿角为 0°的超亲水性薄膜 .     

Synthesis and characterization of hollow Si–SiC composite nanospheres from hollow SiO2/C nanospheres

Journal of Sol-Gel Science and Technology - Hollow SiO2 nanospheres were fabricated by a modified Stöber method. Hollow Si–SiC composite nanospheres were firstly prepared by reducing the...     

TiO2/SiO2纳米薄膜的光催化活性和亲水性

通过sol gel工艺在钠钙玻璃表面制备了均匀透明的TiO2/SiO2复合纳米薄膜.实验结 果表明: 当SiO2添加量较高时, TiO2/SiO2复合纳米薄膜的光催化活性明显降低;当SiO2添加 量较低时,TiO2/SiO2复合薄膜的光催化活性无明显变化.在TiO2薄膜中添加SiO2,可以抑制薄 膜中TiO2晶粒的长大,同时薄膜表面的羟基含量增加, 水在复合薄膜表面的润湿角下降, 亲 水能力增强.当SiO2含量为10％－20％（摩尔分数）时获得了润湿角为0°的超亲水性薄膜.     

中空SiO_2纳米微球的制备与表征

在乙醇/氨水介质中,将SiO2包覆在聚乙烯吡咯烷酮(PVP)功能化的聚苯乙烯(PS)微粒表面,利用一步法得到了中空纳米二氧化硅微球;研究了影响中空纳米二氧化硅微球形成的主要因素,并探讨了中空纳米SiO2微球的可能形成机理.结果表明,在一定的反应时间下,当氨水用量为0.6 mL、温度为70℃时,可以获得空心结构的SiO2纳米微球;通过控制四乙基原硅酸盐(TEOS)的量可以调节微球的包覆层厚度.     

Enhanced photocatalytic degradation of C.I. Basic Violet 2 using TiO2-SiO2 composite nanoparticles

In this report, TiO(2) -SiO(2) composite nanoparticles were prepared by the thermal hydrolysis method using titanium tetrachloride and tetraethylorthosilicate as TiO(2) and SiO(2) precursors, respectively. The prepared nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption/desorption and UV-Vis diffuse reflectance spectroscopy (DRS). The results indicated that, in comparison with pure TiO(2), TiO(2)-SiO(2) composite nanoparticles had a higher thermal stability, which prevents phase transformation from anatase to rutile. In addition, the TiO(2)-SiO(2) nanoparticles had a higher specific surface area, larger pore volume, greater band gap energy and smaller crystallite size. Thus, the surface area of TiO(2)-40% SiO(2) composite nanoparticles was about 17 times higher than that of pure TiO(2) nanoparticles. The photocatalytic activity of TiO(2)-SiO(2) composite nanoparticles in the photodegradation of C.I. Basic Violet 2 was investigated. The photodegradation rate of Basic Violet 2 using TiO(2)-40% SiO(2) nanoparticles calcined at 600°C was much faster than that using pure TiO(2) and Degussa P25 TiO(2) by 10.9 and 4.3 times, respectively. The higher photoactivity of the TiO(2)-SiO(2) composite nanoparticles was attributed to their higher surface area, larger pore volume, greater band-gap energy and smaller crystallite size compared with pure TiO(2).     

TiO2/SiO2复合材料的制备与表征

以钛酸四丁酯和正硅酸乙酯为原料,采用溶胶凝胶法和水解法相结合,在室温下制备了两种形态的TiO2/SiO2复合材料.采用透射电镜、傅里叶红外光谱、X射线衍射和紫外-可见光谱等测试方法对所得复合材料进行了表征,并对其光催化降解甲基橙溶液的性能进行了研究.结果表明:对TiO2进行表面处理制备的TiO2/SiO2复合材料比以SiO2为载体制备的TiO2/SiO2复合材料在光催化和抗紫外线性能上更优异.     

The preparation of composite microsphere with hollow core/porous shell structure by self-assembling of latex particles at emulsion droplet interface

A submicrometer-scaled polystyrene/melamine-formaldehyde hollow microsphere composite was prepared by self-assembling of sulfonated polystyrene (SPS) latex particles at the interface of emulsion droplets and then being fixed in place using a hard melamine-formaldehyde (MF) composite layer. For control-released purposes, the influential factors that control the size and uniformity of the packed-droplets and the permeability of the composite shell, including the initial particle location, the hydrophilicity and the size of colloidal templates, the oil phase solvent and reserving time of emulsions after the addition of MF prepolymer, were further studied. Relatively uniform sized particle packed-droplets with an average diameter of 10 microm were obtained. The assembled SPS particles kept ordering and minimal conglutination after the preparation of composite microspheres, which allows of controlling the permeability from the interstices between the particles. Porous-mesh-structured MF composite layer was formed to further control the permeability. The morphology of emulsions and composite microspheres were characterized by optical microscopy, scanning and transmission electron microscopy.     

TiO2/SnO2复合空心球在染料敏化太阳能电池中的应用

采用模板辅助法制备了SnO2/TiO2复合空心球,样品直径为1.5~4.0μm,比表面积达到了92.9 m^2·g^-1,复合空心球表现出优越的光散射性能.以这种复合空心球作为染料敏化太阳能电池的光阳极,电池的光电转换效率可达到7.72%,高于SnO2微米球(2.70%)和TiO2微米球(6.26%).此外,以锐钛矿型TiO2纳米晶作为底层,SnO2/TiO2复合空心球作为光散射层制备的双层结构光阳极,电池光电转换效率进一步提升至8.43%.     

耐环境性SiO2/SiO2-TiO2 增透膜的设计与制备

根据膜层设计理论设计出以K9玻璃为基体的耐环境性的双层增透膜, 这种增透膜在特定波长处具有超高的透过率. 以盐酸为催化剂, 分别以正硅酸乙酯和钛酸丁酯为前驱体制备了SiO2和TiO2溶胶, 将SiO2和TiO2溶胶按一定比例混合得到SiO2-TiO2复合溶胶. 通过改变复合溶胶中SiO2的含量调节复合膜的折射率, 通过改变提拉速度控制薄膜的厚度. 实验结果表明, 双层增透膜在550 nm处的透过率达到99.9%. 增透膜经较强机械摩擦后峰值透过率基本保持不变, 表明该增透膜具有优良的耐摩擦性. 进一步采用六甲基二硅氮烷对增透膜表面进行修饰, 修饰后增透膜的接触角增大至98.3°, 增透膜的疏水性及环境稳定性得到较大提高.     

Mesoporous TiO2/SiO2 composite nanofibers with selective photocatalytic properties

Mesoporous TiO2/SiO2 composite nanofibers with a diameter of 100-200 nm and silica shell thickness of 5-50 nm have been fabricated by a sol-gel combined two-capillary co-electrospinning method; the composite nanofibers exhibited selective photocatalytic activity based on the decomposition of Methylene Blue, Active Yellow and Disperse Red.     

齐聚苯撑乙烯-二氧化硅复合膜的制备及其光电性质研究

聚苯撑乙烯（PPV）及其复合物由于光致发光效率高及电荷传输性能好,故在光电器件方面的应用已受到广泛重视,但聚合物材料有自身的局限性,主要是：（1）在矣合时残留杂质影响器件的稳定性;（2）聚合物结构复杂多变使其发光机理与微观结构模糊不清。因此具有化学结构,化学纯度高的剂聚苯撑乙烯（oligo-PV)及其复合物的合成和理论研究吸引了许多研究者。     

Synthesis of multifunctional metal- and metal oxide core@mesoporous silica shell structures by using a wet chemical approach

We demonstrate a facile wet chemical approach for fabricating spherical metal/metal-oxide core@mesoporous silica shell hybrid nanoparticles with different core and shell thicknesses. Vertically aligned mesoporous silica (mSiO(2) ) shells were fabricated over the pre-synthesized spherical SiO(2) nanoparticles through a three-step strategy: 1)?synthesis of core materials, 2)?covering the core with an organic-inorganic composite layer, and 3)?removing the organic template through calcinations in air. The mechanisms of hybrid structure formation are proposed. The multifunctional nature of the hybrid structures could be induced by incorporating guest ions/molecules, such as Ag, Mn, and TiO(2) , into the pores of an mSiO(2) shell. Mn and TiO(2) cluster- incorporated composite structures have been tested to be antioxidizing agents and effective photocatalysts through electron spin resonance, radical scavenging tests, and the photocatalytic degradation of rhodamine B. The possibility of incorporating several hetero-element guest clusters in these mesoporous composite particles makes them highly attractive for multifunctional applications.     

Study on Fe3O4/polyaniline electromagnetic composite hollow spheres prepared against sulfonated polystyrene colloid template

Fe₃O₄/polyaniline (PANI) composite hollow spheres were prepared by using sulfonated polystyrene (SPS) microspheres as templates. The sulfonic acid groups were applied to induce absorbing Fe₃O₄ nanoparticle, and subsequently, conductive PANI was grown. Finally, the polystyrene cores were selectively dissolved to yield composite hollow microspheres with electromagnetic properties. The analysis results indicated that the adsorption of Fe₃O₄ on template core by electrostatic interaction resulted in magnetic composite microspheres. The conductivity of composite hollow spheres was remarkably increased after polyvinylpyrrolidone modification which favored the growth of PANI on SPS/Fe₃O₄ and enhanced the integrity of hollow microspheres. The saturated magnetization of the composite hollow microspheres was tuned from 2.7 to 9.1 emu/g, and the conductivity was in the range from 10^?2 to 10⁰?S/cm.     

Porous carbon and carbon composite hollow spheres

In this communication, we propose a template approach toward synthesis of carbon hollow spheres by direct carbonization of highly crosslinked sulfonated polystyrene gel hollow spheres (sPS). The sulfonic acid group can facilitate carbonization. Moreover, the acid group can also induce a favorable growth of other materials within the sPS gel-forming carbon-based composite shell such as bi-continuous C/SiO₂ and their derivative ceramic SiC. Release of small molecules during polymers decomposition results porous shell.     

以工业粉煤灰为原料制备 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂及其催化性能

2-仲丁基-4,6-二硝基苯酚(DNBP)作为杀虫剂、除草剂和烯烃基芳香族化合物阻聚剂而被广泛地应用于工农业生产中.在 DNBP生产和使用过程中,会产生大量难以降解的有机废水,从而对人类和生态环境造成极大危害.因此,开展含 DNBP废水的处理技术和方法研究具有重要的现实意义. TiO2半导体材料由于具有良好的光化学特性和电化学行为,近几十年来一直是光催化领域的研究热点.在能量等于或大于 TiO2的带隙能级的辐照光照射下, TiO2可以产生光生电子/空穴对(e-/h+).光生电子和空穴分别与 TiO2表面被吸附的 H2O和 O2分子反应,生成具有强氧化性的活性羟基自由基(?OH),对硝基酚类有机污染物具有较强的降解能力. TiO2光催化反应属于非均相反应,反应在催化剂的表面进行,催化剂对污染物的吸附是影响其催化降解性能的重要因素.但是,传统 TiO2光催化剂存在比表面积小,对有机污染物吸附能力差,光生电子与空穴易于复合等缺陷,限制了 TiO2光催化技术的进一步发展和在水处理领域中的大规模应用.我们基于气凝胶具有多孔性、大比表面积和高孔隙率的特点,以富含硅、铝的工业废弃物粉煤灰为反应原料,首先利用碱熔法和常压干燥技术制备出 SiO2-Al2O3气凝胶.在此基础上,以钛酸四丁酯(TBOT)为反应前体, SiO2-Al2O3气凝胶为载体,利用酸催化溶胶-凝胶法(sol-gel)制备出 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂.利用 X射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)、N2吸附-脱附(BET)、紫外-可见吸收光谱(UV-vis)等分析测试技术对所制备的 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂结构进行了表征.结果显示,在 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂中,粒径尺寸为10~30 nm的锐钛矿型 TiO2纳米颗粒均匀分散在 SiO2-Al2O3气凝胶载体上. TiO2/SiO2-Al2O3气凝胶三元复合光催化剂呈现典型介孔材料的 IV型等温线. SiO2-Al2O3气凝胶的加入极大提高了 TiO2光催化剂的比表面积和对有机污染物的吸附性能,但是对 TiO2光波吸收范围影响不大.在制备出 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂基础上,进一步对其在可见光条件下的光催化性能进行了研究.以500 W的 Xe灯光源模拟自然太阳光, DNBP为探针污染物分子,系统考察了可见光照射条件下溶液 pH值、光催化剂用量、光反应时间、DNBP溶液初始浓度不同因素对 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂催化活性的影响.结果表明, TiO2/SiO2-Al2O3气凝胶三元复合光催化剂对 DNBP有机污染物的吸附率和光降解率明显高于纯 TiO2样品.在 DNBP溶液初始浓度为0.167 mmol/L, pH =4.86,催化剂用量6 g/L,光照时间5 h的条件下, TiO2/SiO2-Al2O3气凝胶三元复合光催化剂对 DNBP的降解率几乎高达100%.根据 Langmuir-Hinshelwood方程,在低浓度下光催化降解反应符合一级反应动力学.所制备的 TiO2/SiO2-Al2O3气凝胶三元复合光催化剂具有良好的稳定性和重复利用性能.重复利用5次后, TiO2/SiO2-Al2O3气凝胶三元复合光催化剂对 DNBP的降解率仍高达90%以上.利用紫外-可见分光光度计、气相-质谱联用仪对 DNBP降解中间产物进行了分析,探讨了 DNBP的光催化降解机理.     

纳米结构TiO2/SiO2的逐层自组装

采用逐层自组装方法在二氧化硅球表面交替组装了十二烷基硫酸钠单分子膜和二氧化钛纳米粒子膜 ,该复合多层膜经高温煅烧后得到了核壳型纳米结构二氧化钛 /二氧化硅复合颗粒 .利用XRD ,SEM ,X射线能谱等对复合颗粒进行了表征 .结果表明 :二氧化钛在复合颗粒表面排列紧密、均匀 ,粒径在 5 0nm左右 ,为锐钛矿型结构 .复合颗粒中二氧化钛的含量随组装层数的增加而均匀增加