中空纳米二氧化硅复合微球的制备及其对蛋白的亲和分离

利用水热法合成了中空巯基纳米二氧化硅微球(SiO₂-SH), 然后在其表面修饰亚氨基二乙酸基团(-IDA), 形成了中空SiO₂-SH/IDA双功能化纳米微球。利用该纳米微球表面的-SH和-IDA双功能团, 可以更多的吸附溶液中的Ni²⁺, 形成SiO₂-SH/IDA-Ni²⁺复合微球从而可以更好的分离以六聚组氨酸为标签的(His-tagged)蛋白。结果显示制备的样品对分离His-tagged蛋白具有广谱性, 并且具有较好的再生能力。     

二氧化硅复合微球的制备及其对His-tagged融合蛋白质的分离

采用水热法合成了巯基纳米二氧化硅(SiO2-SH),并在其表面修饰亚氨基二乙酸基团(-IDA)得到SiO2-SH/IDA微球.该微球从溶液中可吸附更多的Ni 2+形成SiO2-SH/IDA-Ni 2+复合微球.研究结果表明,利用该复合微球可以较好地分离以组氨酸为标签(His-tagged)的融合蛋白.     

双功能化磁性纳米修复剂对多重金属的快速、高效钝化行为

采用“一锅法”制备了四氧化三铁/半胱氨酸（Fe₃O₄/Cys）磁性纳米微球,随后对Fe₃O₄/Cys进行亚氨基二乙酸（IDA）修饰得到Fe₃O₄/Cys/IDA磁性双功能化纳米微球。研究发现Fe₃O₄/Cys中的L-Cys是通过—SH基团接枝到Fe₃O₄表面的,随后IDA分子中的羧基与Fe₃O₄/Cys中的—NH₂形成酰胺键,最终形成多支链多羧基的Fe₃O₄/Cys/IDA磁性纳米修复剂。基于修复剂表面短支链-长支链交替的多羧基结构,实现了羧基基团的高密度接枝。同时,Fe₃O₄/Cys/IDA磁性纳米微球对Pb²⁺、Cd²⁺、Cu²⁺、Co²⁺、Ni²⁺、Zn²⁺为专性吸附,而对Hg²⁺属于非专性吸附,且吸附重金属后得到的钝化产物均表现了良好的稳定性。另外,Fe₃O₄/Cys/IDA对重金属离子的吸附符合Langmuir模型,属于单层均相吸附,其吸附过程符合准二级动力学模型,最大吸附量为49.05 mg·g^-1。     

有序Au/Ag纳米碗阵列的简易制备及其表面增强拉曼散射性能

通过湿法化学合成基于SiO₂胶体晶体的大面积有序Au/Ag纳米碗(Au/AgNB)阵列。首先,在玻璃基板上组装3D SiO₂胶体晶体作为模板。然后,以Au纳米颗粒(AuNP)为种子,通过原位生长法在SiO₂模板上沉积一层Au纳米壳(AuNS)。再通过HCHO还原Ag⁺成Ag⁰,进一步在AuNS表面沉积Ag纳米壳,形成Ag/Au双纳米壳(Ag/AuNS)阵列。最后通过丙烯酸酯改性双向取向聚丙烯(BOPP)膜方便地获得了单层有序反转Ag/AuNB阵列。这种有序Au/AgNB阵列具有更佳的表面增强拉曼散射(SERS)活性,其SERS分析增强因子(AEF)可达2.23×10⁷。     

Bi2MoO6中空微球的制备及其光催化性能

基于Bi₂MoO₆与BiOI晶体结构上的相似性,以BiOI为自牺牲模板,通过原位转化法制备得到了Bi₂MoO₆中空微球。通过对时间演化中间产物以及不同温度下产物的物相和形貌进行分析,得出形成Bi₂MoO₆中空微球的最佳反应时间为8h,最佳温度为120℃。对所制备的Bi₂MoO₆中空微球物相、形貌、比表面积以及光学性能进行了研究,表明Bi₂MoO₆中空微球表面较为疏松,内部为中空结构,具有较大的比表面积,为61m²·g^-1。在可见光下,以甲基橙为降解对象,对所制备样品的光催化性能进行了评价。结果表明所制备的Bi₂MoO₆中空微球能在80min内完全降解甲基橙,性能优于不同时间下的中间产物和片状结构Bi₂MoO₆的光催化性能,具有优越的可见光光催化性能。     

纳米SiO_2亲和吸附剂的制备及性能

采用水热法一步合成了巯基纳米二氧化硅(SiO_2-SH),随后在其表面修饰亚氨基二乙酸基团(-IDA)得到了SiO_2-SH/IDA,利用-SH和-IDA双官能团更多的吸附溶液中的Ni~(2+),从而得到SiO_2-SH/IDA-Ni~(2+)纳米亲和吸附剂.制备的亲和吸附剂可直接用于六聚组氨酸为标签的(His-tagged)融合蛋白的分离纯化.利用TEM、FT-IR、TG、SDS-PAGE等大型仪器表征了样品的形貌、结构及亲和分离能力.结果表明制备的SiO_2-SH/IDANi~(2+)纳米亲和吸附剂平均粒径为60nm,对His-tagged蛋白具有较好的特异性和较低的检测限(约为1.9×10~(-5)mol/L),且该吸附剂再生能力较强,再生3次后对目标蛋白仍具有较好的分离效果.     

Bi2MoO6中空微球的制备及其光催化性能

基于Bi₂MoO₆与BiOI晶体结构上的相似性,设计以BiOI为自牺牲模板,通过原位转化法制备得到了Bi₂MoO₆中空微球。通过对时间演化中间产物以及不同温度下产物的物相和形貌进行分析,得出形成Bi₂MoO₆中空微球的最佳反应时间为8 h,最佳温度为120℃。对所制备的Bi₂MoO₆中空微球物相、形貌、比表面积以及光学性能进行了研究,表明Bi₂MoO₆中空微球表面较为疏松,内部为中空结构,具有较大的比表面积,为61 m²·g^-1。在可见光下,以甲基橙为降解对象,对所制备样品的光催化性能进行了评价。结果表明所制备的Bi₂MoO₆中空微球能在80 min内完全降解甲基橙,性能优于不同时间下的中间产物和片状结构Bi₂MoO₆的光催化性能,具有优越的可见光光催化性能。     

pH值调节方式对LAB辅助合成纳米Cu2O微球的影响与组装机理

以Cu(Ac)₂为原料,两性表面活性剂月桂酰胺丙基甜菜碱(LAB)为模板,采用两种不同的调节pH值方式制备了Cu₂O纳米材料.表征结果表明两种调节pH值方式均可获得Cu₂O纳米微球,并都呈立方晶相,而且样品的红外吸收峰、固体紫外吸收峰都不同程度的发生了蓝移;第一种Cu₂O纳米微球由针状纳米粒子积聚而成,针状纳米粒子间空隙孔径主要分布在25~50 nm之间,比表面积为22 m²·g^-1,禁带宽度为2.15 eV;第二种Cu₂O纳米微球由小的纳米球状体堆积而成,球状体间孔道直径集中在25~50 nm和50~125 nm两个区域,比表面积为9 m²·g^-1,禁带宽度为2.46 eV.两种不同的调节pH值方式获得的Cu₂O纳米微球,其反应历程和自组装机理存在不同.     

Fe3+掺杂三维分级纳米Bi2WO6的合成及其光催化活性增强机理

利用水热法合成了Fe³⁺掺杂的三维分级纳米Bi₂WO₆,借助X射线衍射（XRD）、场发射扫描电镜（FE-SEM）、透射电镜（HRTEM）、能谱（EDS）、紫外可见漫反射（UV-Vis-DRS）等测试手段对所得样品的相组成、形貌和谱学特征进行了表征。选择罗丹明B为模型污染物研究所得样品在可见光下的催化活性。结果表明,Fe³⁺掺杂Bi₂WO₆为新颖的分级纳米结构,且Fe³⁺掺杂能有效提高Bi₂WO₆的光催化活性,Fe³⁺掺杂量对Bi₂WO₆活性的影响显著;实验结果还表明,所得Fe³⁺掺杂Bi₂WO₆催化剂的稳定性较好,易于回收。此外,还对Fe³⁺掺杂Bi₂WO₆的光催化活性增强机理进行了研究,缺电子的Fe³⁺作为电子捕获中心有利于促进光生电子-空穴对的分离,从而提高Bi₂WO₆的光催化活性。     

掺杂和取代对红色荧光材料SrAl12O19:Mn4+发光性能的影响

SrAl₁₂O₁₉：Mn⁴⁺是一种用于高显色性白光发光二极管的候选红色荧光材料。本论文研究了Mg²⁺、Zn²⁺和Ge⁴⁺离子的掺杂效应以及Ga³⁺、Ca²⁺和Ba²⁺离子的取代效应对SrAl₁₂O₁₉：Mn⁴⁺荧光材料性能的影响。样品通过高温固相反应制备,焙烧温度在1 250~1 500 ℃之间。利用X射线衍射技术表征了材料的相纯度,用荧光激发光谱和发射光谱表征了材料的荧光性能。研究结果指出,与未进行Mg²⁺或Zn²⁺掺杂的样品相比,Mg²⁺或Zn²⁺离子对Al³⁺格位的掺杂可以使材料的发光强度提高~60%,其原因被认为是掺杂促进了激活剂Mn⁴⁺离子进入晶格,其过程可以表示为：MO+MnO₂⇔M_Al^''+M_Al^·+3O_O^×（M=Mg,Zn）,电子顺磁共振谱支持这一结果。Ge⁴⁺离子的掺杂使材料的发光性能明显下降。Ga³⁺离子可以取代Al³⁺离子形成全范围的固溶体,其中少量Ga³⁺离子的掺杂可以使材料的荧光发射强度提高~13%,而掺杂量进一步提高使材料的荧光性能下降。Ca²⁺和Ba²⁺对Sr²⁺的取代仅形成有限范围的固溶体。Ca²⁺的取代使材料的发光性能提高;而 Ba²⁺的取代使材料的发光强度下降。     

Synthesis of silica nanospheres with Ni2+-iminodiacetic acid for protein separation

Silica (SiO₂) nanospheres (NSs) with immobilized metal ligands have been prepared for the affinity separation of proteins. First, SiO₂ NSs were prepared by controlled hydrolysis of tetraethoxysilane in a basic aqueous-ethanol solution. Then through reaction of iminodiacetic acid (IDA) with 3-glycidoxypropyltrimethoxysilane and immobilization of them onto the surfaces of above SiO₂ NSs, novel affinity adsorbents with IDA chelating groups were obtained. After chelating Ni²⁺ ions, the SiO₂–IDA–Ni²⁺ NSs were applied to separate his-tagged proteins directly from the mixture of lysed cells. The SiO₂–IDA–Ni²⁺ NSs present negligible nonspecific protein adsorption and high protein binding ability (28.3 mg/g).     

Design of Silica@Au Hybrid Nanostars for Enhanced SERS and Photothermal Effect

Core-shell nanostructures of silicon oxide@noble metal have drawn a lot of interest due to their distinctive characteristics and minimal toxicity with remarkable biocompatibility. Due to the unique property of localized surface plasmon resonance (LSPR), plasmonic nanoparticles are being used as surface-enhanced Raman scattering (SERS) based detection of pollutants and photothermal (PT) agents in cancer therapy. Herein, we demonstrate the synthesis of multifunctional silica core – Au nanostars shell (SiO₂@Au NSs) nanostructures using surfactant free aqueous phase method. The SERS performance of the as-synthesized anisotropic core-shell NSs was examined using Rhodamine B (RhB) dye as a Raman probe and resulted in strong enhancement factor of 1.37×10⁶. Furthermore, SiO₂@Au NSs were also employed for PT killing of breast cancer cells and they exhibited a concentration-dependent increase in the photothermal effect. The SiO₂@Au NSs show remarkable photothermal conversion efficiency of up to 72 % which is unprecedented. As an outcome, our synthesized NIR active SiO₂@Au NSs are of pivotal importance to have their dual applications in SERS enhancement and PT effect.     

Thiol-functionalized Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/SiO<Subscript>2</Subscript> microspheres with superparamagnetism and their adsorption properties for Au(III) ion separation

Thiol-functionalized Fe₃O₄/SiO₂ microspheres (Fe₃O₄/SiO₂-SH) with high saturation magnetization (69.3 emu g^–1), superparamagnetism, and good dispersibility have been prepared by an ethylene glycol reduction method in combination with a modified Stöber method. The as-prepared composite magnetic spheres are characterized with fourier transform infrared spectroscopy (FT-IR), zeta potential, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and superconducting quantum interference magnetometer, and tested in separation of Au(III) ions from aqueous solutions. The data for Au(III) adsorption on Fe₃O₄/SiO₂-SH are analyzed with the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models, and the pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetics models. The adsorption behaviors of Au(III) on Fe₃O₄/SiO₂-SH follow the Langmuir isotherm model, and the adsorption process conforms to the pseudo-second-order kinetic model. The maximum adsorption capacity of Au(III) on Fe₃O₄/SiO₂-SH is 43.7 mg g^–1. Acetate anions play an important role yet Cu(II) ions have little interference in the adsorption of Au(III) on the adsorbent. A satisfactory recovery percentage of 89.5% is acquired by using an eluent with 1 M thiourea and 5% HCl, although thiols have a high affinity to Au(III) ions based on the hard-soft acid-base (HSAB) theory by Pearson.     

The flow-through silica as the matrix to immobilize gold nanoparticles for HPLC applications

In the present study, the flow-through silica, featured with hierarchical pores, i.e., tunable mesopores and penetrable macropores, was attempted as the chromatographic stationary phase matrix to immobilize gold nanoparticles (AuNPs). It was first modified by mercapto groups (named as SiO₂-SH), and then by AuNPs (named as SiO₂-S-Au). Thanks to the characteristic macropores, the column backpressure of SiO₂-S-Au was comparable to SiO₂-SH, which effectively overcame the difficulty of high column backpressure upon the nanoparticles were introduced to the chromatographic matrix. Both the reversed-phase and hydrophilic interaction liquid chromatographic performance were observed on these two columns but with different selectivities. Hydrophobic, hydrophilic, hydrogen bond and electrostatic interactions between the SiO₂-S-Au stationary phase and analytes could contribute to the retention. The SiO₂-S-Au column showed excellent aqueous compatibility by “Stop-flow” test with the relative standard deviations (RSD) of analyte’s k (capacity factor) values from 0.59% to 2.88%. The reproducibility of SiO₂-S-Au was acceptable with RSDs of analyte’s k values in the range of 3.13%-5.03%. In addition, compared with the SiO₂-SH column, the SiO₂-S-Au column had better separation performance and selectivity. The results demonstrated that the flow-through silica was a promising matrix for nanoparticles with low backpressure and different selectivities.     

ADSORPTION OF UO2 2+ BY POLYETHYLENE HOLLOW FIBER MEMBRANE WITH AMIDOXIME GROUP

The polyethylene (PE) membrane was prepared by the radiation-induced grafting of acrylonitrile (AN) onto PE hollow fiber and by the subsequent amidoximation of cyano groups in poly-AN graft chains. The adsorption characteristics of the chelating hollow fiber membrane was examined as the solution of UO₂ ²⁺ permeated across the chelating hollow fiber membrane. The inner and outer diameter increased with an increasing grafting yield, whereas, the pure water flux and pore diameter decreased with an increasing grafting yield. The adsorption of UO₂ ²⁺ by the chelating hollow fiber membranes increased with an increasing amidoxime group. The adsorbed amount of UO₂ ²⁺ in the uranyl acetate solution was higher than that in the uranyl nitrate solution. The adsorbed amount of UO₂ ²⁺ is higher than that of Cu²⁺ when the solution of UO₂ ²⁺ and Cu²⁺ permeated across the chelating membrane, respectively. The adsorption characteristics of UO₂ ²⁺ by the amidoxime group-chelating fiber membrane in the presence of Na¹⁺ and Ca²⁺ showed a high selectivity for UO₂ ²⁺ even though there was a high concen-tration of Na¹⁺ and Ca²⁺ in the inlet solution.     

Hierarchical Porous ZnMn2O4 Hollow Nanotubes with Enhanced Lithium Storage toward Lithium‐Ion Batteries

We have purposefully developed a smart template‐engaged methodology to efficiently fabricate well‐defined ternary spinel ZnMn₂O₄ hollow nanotubes (NTs). The procedure involves coating carbon nanotubes (CNTs) with ZnMn₂O₄ nanosheets (NSs), followed by heating at high temperature in air to oxidize the CNT template. Physicochemical characterization demonstrated that the formed ZnMn₂O₄ NTs with a diameter of approximately 100 nm were composed of assembled NSs and/or nanoparticles (NPs) as building blocks and possessed numerous nanopores of several nanometers in the sidewall of the NTs. In favor of the intrinsic structural advantages, the resulting ZnMn₂O₄ NTs exhibited superior electrochemical lithium‐storage performance with a large capacity, good rate behavior, and excellent cyclability when evaluated as promising anodes for lithium‐ion batteries (LIBs). The remarkable electrochemical performance was rationally ascribed to the appealing one‐dimensional (1D) porous hollow tubular architecture with nanoscale subunits and mesopores in the sidewalls, which decreased the diffusion length for the Li⁺ ions, improved the kinetic process, and enhanced the structural integrity with sufficient void space to tolerate the volume variation during Li⁺‐ion insertion/extraction. These results highlight the promising application of 1D ZnMn₂O₄ NTs as anodes for high‐performance LIBs.     

Graphene-supported cobalt nanoparticles used to activate SiO2-based anode for lithium-ion batteries

Although SiO₂-based anode is a strong competitor to supersede graphite anode for lithium-ion batteries, it still has problems such as low electrochemical activity, enormous loss of active lithium, and serious volume expansion. In order to solve these problems, we used a graphene network loaded with cobalt metal nanoparticles (rGO–Co) to coat SiO₂ porous hollow spheres (SiO₂@rGO–Co). The construction of porous hollow structure and graphene network can shorten the lithium-ion (Li⁺) diffusion distance and enhance the conductivity of the composite, which improves the electrochemical activity of SiO₂ effectively. They also alleviate the volume expansion of the anode in the cycling process. Moreover, nano-scale cobalt metal particles dispersed on graphene catalyze the conversion reaction of SiO₂ and activate the locked Li⁺ in Li₂O through a reversible reaction, which improves the charge and discharge capacity of the anode. The capacity of SiO₂@rGO–Co reaches 370.4 mAh/g after 100 cycles at 0.1 A/g, which is 6.19 times the capacity of pure SiO₂ (59.8 mAh/g) under the same circumstance. What is more, its structure also exhibits excellent cycle stability, with a volume expansion rate of only 13.0% after 100 cycles at a current density of 0.1 A/g.     

Sol–Gel Chemistry for Ba2+ Sensors to Allow Oil Production Engineered Nanometrically

Work on the development of a Ba^{2 +}-sensitive sol–gel based optical fiber (OF) for use in oil wells is described. The optical fiber (OF) has on its surface a Ba^{2 +} chelating ligand (L) immobilized at a 2–16 wt% loading immobilized in a porous SiO₂ sol–gel host. The authors report sol–gel routes to these SiO₂ and L/SiO₂ nanocomposites and describe their characterization by XPS, fluorescence, NMR, UV-vis and BET methods. They also report on the sol–gel coating and its selectivity to Ba^{2 +}_(aq).     

锌离子掺杂的二氧化钛介孔空心微球的制备及光催化性能

以二氧化硅为模板,钛酸四丁酯(TBOT)为钛源,硝酸锌为锌源,采用溶胶凝胶法制备了锌离子掺杂的介孔二氧化钛空心微球。采用X射线衍射(XRD)、比表面积(BET)、透射电镜(TEM)、扫描电镜(SEM)和X射线光电子能谱(XPS)等技术对样品进行表征,以亚甲基蓝(MB)的光催化降解为目标反应评价其光催化活性。结果表明,去核之后的复合微球为空心微球,壁厚为20 nm左右。钛酸四丁酯溶液的滴加时间对微球的形貌影响较大,当滴加时间大于15 min时,可以得到结构清晰的空心微球。用氢氧化钠溶液去除二氧化硅核,反应90 min,二氧化硅可以被完全去除。X射线衍射表明,实验得到的掺杂锌离子的空心微球和没有掺杂锌离子的空心微球都是锐钛矿。当锌离子的摩尔分数为0.3%时,二氧化钛空心微球的晶粒尺寸最小,比表面积最大,催化亚甲基蓝降解的效率最高。