新型磁性复合材料Fe_3O_4@TiO_2的制备与表征

以Fe3O4为核心,采用具有亲水性基团的碳层为连接桥梁,利用钛酸丁酯水解过程中产生的二氧化钛与亲水性基团的键合作用,制得Fe3O4@Ti O2磁性复合材料.通过改变原料的用量和反应条件,采用SEM、TEM、XRD等测试手段,对磁性复合材料的粒径大小、分散性以及改性效果进行了探究.结果表明:该磁性复合材料直径为300 nm,分散性良好,改性效果优异.     

C_3N_4-TiO_2复合光催化剂的制备及其太阳光催化性能

以TiO_2和三聚氰胺为原料,在超声搅拌作用下于水相中将两种物质进行混合,而后烘干并采用一步固相法将不同质量比的TiO_2和三聚氰胺混合物置于马弗炉中进行高温煅烧,制得C_3N_4-TiO_2复合光催化剂;对制备的复合物进行X射线衍射、荧光光致发光光谱、扫描电子显微镜、紫外-可见吸收光谱对其理化性能进行表征;以罗丹明B为目标污染物,使用氙灯模拟太阳光光源,对复合物的光催化性能进行评价。结果表明,C_3N_4的引入增强了复合光催化剂的吸附能力;TiO_2与类石墨型C_3N_4的复合,增强了光催化剂对光的吸收能力,C_3N_4-TiO_2复合光催化剂的光催化性能较纯TiO_2有明显提高,TiO_2对污染物罗丹明B的降解效率可达21%,C_3N_4-TiO_2复合光催化剂的降解效率可达99%。     

磁性二氧化硅纳米粒子的制备及性能

为了克服磁性四氧化三铁纳米粒子易团聚、易氧化、耐酸性差等缺点,提高其在催化剂、靶向药物载体、生物分离、核磁共振成像、磁热疗等领域的利用效率,采用共沉淀法合成了四氧化三铁纳米粒子,然后以其为核用Stber法制备出二氧化硅包覆四氧化三铁的复合纳米粒子. 对包覆前及包覆后的磁性纳米粒子分别进行了X射线衍射、透射电子显微镜、振动样品磁强计的表征,并研究了二氧化硅的包覆对四氧化三铁纳米粒子磁性和耐酸性的影响. 实验结果表明:磁性四氧化三铁及磁性二氧化硅纳米粒子的粒径分别为约20 nm和40 nm;磁性四氧化三铁的磁饱和强度为5.7 emu/g,磁性二氧化硅纳米粒子的磁饱和强度也达到5.1 emu/g;此外,在稍微降低磁性的条件下,表面二氧化硅的包覆显著改善了四氧化三铁纳米粒子的分散性和耐酸性.     

磁性高分子微球Fe3O4／PMMA的制备与表征

以油酸作为表面活性剂,采用化学共沉淀法制备了具有良好晶型、分散性好的纳米四氧化三铁。以甲基丙烯酸甲酯（MMA）作为反应单体,DVB为交联剂,使用水溶性引发剂KPS,采用单体聚合法制备磁性高分子微球Fe30dPMMA,该磁性高分子微球具有明显的核壳结构,粒子尺寸约为500nm。     

高效富集微囊藻毒素的Fe_3O_4@ODA@SiO_2磁性粒子的制备

通过水热合成法制备Fe_3O_4磁性粒子,并采用溶胶法在其表面修饰十八胺(ODA),制得易于富集微囊藻毒素的Fe_3O_4@ODA@SiO_2磁性粒子,通过扫描电镜、震动磁强计进行表征,并将其应用于磁性固相萃取技术对水中MC-LR和MC-RR两种藻毒素进行富集,取得了高效富集效果.     

磁性纳米二氧化硅的制备与性能研究

纳米二氧化硅(nSiO2)微球因其比表面积大、表面吸附力强、其表面富含可供改性的化学官能团,并且稳定性高,目前已经广泛用于模板化包药、药物运载、药物缓释等领域.以磁性Fe3O4为核,采用共沉淀法制备出有核壳结构的磁性纳米二氧化硅(nMSiO2)微球,在药物传输以及荧光标记诊断方面可以实现磁导向,具有潜在的应用价值.在nMSiO2微球上接枝可以发荧光的异硫氰酸(FITC),可以实现磁引导的同时示踪.获得的nMSiO2微球利用磁性测试、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和红外光谱(FTIR)进行结构和性能的表征,结果表明,nSiO2微球包裹了磁性Fe3O4后,nMSiO2微球具备磁性,且其性能与纯nSiO2有了本质的差异,接枝异硫氰酸且能够发出荧光.     

Bi_2O_3/TiO_2复合光催化剂对甲基橙的光催化作用

以溶胶-凝胶法制备了Bi2O3/TiO2复合光催化剂,用TEM、HRTEM、XRD、Raman、FTIR、PL、UV-Vis DRS等对其结构、性质进行表征,并以甲基橙为有机污染物对Bi2O3/TiO2复合光催化剂活性进行研究。结果表明:复合少量Bi2O3可抑制TiO2由锐钛矿相到金红石相相变及其颗粒的生长。n(Bi)∶n(Ti)=0.017 5配比的Bi2O3/TiO2复合光催化剂活性最好,当用量为2.5g/L时,25mg/L的甲基橙溶液在500 W氙灯下照射5h后,脱色率达到99.4%,2.1倍于Degussa P25TiO2。     

熔喷非织造布用磁性Fe3O4@SiO2/PLA共混材料的性能分析

采用溶剂热法制备磁性四氧化三铁(Fe₃O₄)纳米粒子,随后利用改进的溶胶-凝胶法制备四氧化三铁与二氧化硅复合纳米粒子(Fe₃O₄@SiO₂),再以聚乳酸(PLA)为基体,通过熔融共混工艺制备Fe₃O₄@SiO₂/PLA共混材料。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)、万能拉伸试验机、熔体流动速率仪(MFR)和振动样品磁强计(VSM)等对共混材料的形貌、结晶结构、热性能、力学性能、熔体流动速率和磁性能进行表征分析。结果表明：添加量为1%(以质量分数计)的Fe₃O₄@SiO₂纳米粒子可在PLA基体中均匀分散,与基体有良好的界面相容性。相比于纯PLA,Fe₃O₄@SiO₂/PLA共混材料的热性能变化不大,当Fe₃O_4<...     

Fe_3O_4/AuNPs磁性复合粒子的制备与表征

通过溶剂热法合成了较大粒径的磁性Fe3O4纳米粒子,使用3-氨丙基三乙氧基硅烷(APTES)在乙醇/异丙醇体系中将其表面功能化一层氨基,随后将金纳米粒子(Au NPs)自组装于Fe3O4粒子表面,得到了Fe3O4/Au NPs纳米粒子;采用透射电子显微镜(TEM)、X-射线衍射(XRD)、振动样品磁强计(VSM)和紫外-可见光吸收光谱仪(UV-Vis)对复合粒子的形态、结构及性质进行表征.结果表明:所制备的Fe3O4磁纳米粒子粒径均一,平均粒径约为250 nm,形状几乎都呈球形,磁性Fe3O4/Au NPs复合粒子包覆均匀、具有良好的的分散性和磁化率,同时兼有磁性和金纳米粒子的特性.     

Fe_3O_4@NiSiO_3磁性纳米粒子对刚果红的吸附性能研究

研究了Fe3O4@NiSiO3磁性纳米粒子对染料刚果红的吸附,吸附动力学结果表明磁性Fe3O4@NiSiO3吸附剂对染料刚果红的吸附等温线符合Freundlich模型,吸附过程符合拟二级动力学方程.吸附热力学结果表明反应是自发吸热过程,反应以物理吸附为主.     

Preparation of TiO2 photocatalyst loaded with V2O5 for O2 evolution

TiO₂ photocatalysts loaded with V₂O₅ were prepared via a modified hydrolysis process, and characterized by X-ray diffraction, transmission electron microscopy, Raman spectra and diffuse reflectance UV-Vis spectra measurements. The photocatalytic activity of V₂O₅/TiO₂ was investigated by employing splitting of water for O₂ evolution. The results indicate that V₂O₅ loading can pronouncedly improve the photocatalytic activity of TiO₂ with Fe³⁺ as an electron acceptor under UV or visible light irradiation. The optimum mass fraction of the loaded V₂O₅ is 8%, and the largest speed of O₂ evolution for 8%V₂O₅ (mass fraction) loaded TiO₂ catalyst is 118.2 μmol/(L·h) under UV irradiation, and 83.7 μmol/(L·h) under visible light irradiation.     

Preparation, characterization and photocatalytic behavior of WO3-TiO2/Nb2O5 catalysts

TiO2/Nb2O5 photocatalyst loaded with WO3 (WO3-TiO2/Nb2O5) was prepared by a modified hydrolysis process, and characterized by X-ray diffractometry, transmission electron microscopy, Raman spectra and UV-Vis diffuse refraction spectroscopy. The photocatalytic activity of WO3-TiO2/Nb2O5 was investigated by employing splitting of water for O2 evolution. The results indicate that WO3 loading can pronouncedly improve the photocatalytic activity of TiO2/Nb2O5 by using Fe3 as an electron acceptor under UV irradiation. The optimum molar fraction of the loaded WO3 is 2%, and the largest speed of O2 evolution for 2% WO3-TiO2/Nb2O5 catalyst is 151.8 μmol/(L·h).     

Fe3O4-10-HCPT及Fe3O4-HCPT@SiO2核壳纳米粒子的制备

为有效控制磁性四氧化三铁纳米粒子在水介质中的分散,防止其聚集.通过控制Na Cl溶液的物质的量浓度,对比研究磁性四氧化三铁纳米粒子在超声前和超声后在盐中的分散情况.实验结果表明,磁性四氧化三铁纳米粒子在0.4 mol/L的氯化钠中分散性最好,聚集度较小;进一步为了制备粒径均匀的复合磁性纳米载药粒子,通过调节10-羟基喜树碱溶液的p H,将10-羟基喜树碱和磁性纳米粒子制备成复合纳米粒子,并将其用二氧化硅包覆制备了复合载药纳米粒子,其复合纳米粒子的粒径大约为120 nm,结果显示通过该方法成功制备了理想的磁性纳米载药粒子.     

Characteristics of magnetic Fe3O4 nanoparticles encapsulated with human serum albumin

Magnetic nanoparticles （Fe304） were prepared by chemical precipitation method using Fe^2＋ and Fe^3＋ salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin（HSA） for magnetic resonance imaging as contrast agent. Characteristics of magnetic particles coated or uncoated were carried out using scanning electron microscopy and X-ray diffraction. Zeta potentials, package effects and distributions of colloid particles were measured to confirm the attachment of HSA on magnetic particles. Effects of Fe3O4 nanoparticles coated with HSA on magnetic resonance imaging were investigated with rats. The experimental results show that the adsorption of HSA on magnetic particles is very favorable to dispersing of magnetic Fe3O4 particles, while the sizes of Fe3O4 particles coated are related to the molar ratio of Fe3O4 to HSA. The diameters of the majority of particles coated are less than 100 nm. Fe3O4 nanoparticle coated with HSA has a good biocompatibility and low toxicity. This new contrast agent has some effects on the nuclear magnetic resonance imaging of liver and the lowest dosage is 20μmol/kg for the demands of diagnosis.     

采用水热法制备磁性Fe_3O_4纳米棒

以FeCl3·6H2O、2-氨基-2-甲基-1-丙醇、水合肼为主要反应物,水热法制备Fe3O4纳米棒。通过扫描电子显微镜(SEM)、X射线衍射分析仪(XRD)和振动磁强计(VSM)等表征手段进行表征,并对Fe3O4纳米棒的形成机理进行探讨。结果表明,制得的Fe3O4纳米棒,具有较高的饱和磁化强度。     

p-n异质结TiO_2/NiO光催化剂的制备及其性能研究

采用溶胶凝胶和浸渍煅烧相结合的方法,制备出了具有p-n异质结结构的球形二氧化钛表面负载氧化镍颗粒的复合光催化剂.利用XRD、TEM、UV-Vis和PL等方法对催化剂的晶相组成、微观结构、吸光性能和光致发光性能等进行了表征.结果表明氧化镍晶粒与二氧化钛晶粒紧密接触形成p-n异质结.氧化镍颗粒的负载使复合光催化剂的吸收带边发生了明显的红移,并进入了可见光区.形成的p-n异质结促进了二氧化钛光生电子和空穴的分离,从而降低了其本征发光光强度.通过在可见光条件下对亚甲基蓝的降解研究了其光催化性能,结果表明,氧化镍颗粒的负载使二氧化钛的光催化效果在可见光区有了显著地提高,并在一定范围内随着氧化镍含量的增加光催化效果也随之提高.     

Optimization of the operating conditions in a TiO2/Fe3O4-SiO2 photocatalytic reactor for the treatment of industrial wastewater containing Procion Red MX-5B

According to the design principle of the central composite experimental,the method of response surface analysis with three factors and three levels was adopted based on one factor test.A second-order quadratic equation for photocatalysis of Procion Red MX-5B was built.Response surface and contour were graphed with the decoloration rate of Procion Red MX-5B as the response value.Based on the analysis of the response surface plots and their corresponding contour plots,effects of pH value,irradiation time and catalyst loading were explored.By using this new method,the optimum decoloration condition was obtained as follows:pH value,1.3;irradiation time,49.9 min;catalyst loading,0.57 g/L.In the optimization,R-Squared and Adj R-Squared correlation coefficients for quadratic model were evaluated quite satisfactorily as 0.9310 and 0.8620,respectively.Under the optimum conditions established,the performance of 99.47% for color removal was experimentally reached.It was found that all factors considered have an important effect on the decolorization efficiency of Procion Red MX-5B.By the ANOVA analysis and model confirmation the optimal solution obtained using RSM was experimentally validated and credible with preferable instructional ability for experiments.     

Structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass

Bi_2O_3-ZnO-B_2O_3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi_2O_3-ZnO-B_2O_3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B_2O_3 content, the transition temperature Tg and softening temperature T_f of Bi_2O_3-ZnO-B_2O_3 system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi-O bond from [BO_3] pyramidal and [BiO_6] octahedral units and B-O from [BO_3] and [BO_4] units. With the decrease of B_2O_3 content, the crystallization tendency of the glass increases. In glass samples B_1 and B_2, crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi-(24)B_2O_(39) phases.     

SnO2及SnO2／Fe2O3复合微米材料的合成及表征

本文首先以SnCl2·2H2O为主要原料,无水乙醇为溶剂,利用溶剂热法于180℃反应24h得到了SnO2微球;再以所制备的SnO2微球为前驱体,FeCl3·6H2O为主要原料,通过水热法得到SnO2／Fe2O3复合材料．利用X射线粉末衍射仪（XRD）和扫描电子显微镜（SEM）对所得产物进行了表征．结果表明：所得的SnO2为四方锡石型,形貌为微球,平均直径约为2．0μm;复合后得到的SnO2／Fe2O3微球平均直径约为2．5μm．其中,Fe2O3为六方赤铁矿型,在复合物的表面以小颗粒的形式存在,尺寸约为200nm．另外,也对SnO3与SnO2／Fe2O3微球的形成过程进行了讨论．     

Ag3PO4/Fe3O4/GO复合催化剂的制备及其可见光催化性能

以氧化石墨烯（GO）为基底,利用共沉淀及离子交换两步法制备Ag₃PO₄/Fe₃O₄/GO 复合光催化剂．通过X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电镜（TEM）、热重（TGA）、振动样品磁强计（VSM）及紫外-可见光谱（UV-Vis DRS, UV-4100,带积分球）对样品的特征基团、微观形貌及磁性质、光学性质等进行了鉴定和表征．光催化脱色实验结果表明：Ag₃PO₄/Fe₃O₄/GO 化剂20 min内对10 mg/L罗丹明B模拟水样的脱色率可达97.6%,高于Ag₃PO₄（73.4%）;Ag₃PO₄/Fe₃O₄/GO 系中引入过硫酸钠可以起到强化光催化性能的作用;另外,Ag₃PO₄/Fe₃O₄/GO 剂表现出良好的活性稳定性、热稳定性及结构稳定性。