聚丙烯酸酯-TiO2杂化材料的制备及其光催化性能的研究

以甲基丙烯酸甲酯(MMA)、丙烯酸正丁酯(BA)、丙烯酸(AA)、钛酸丁酯(TBOT)为主要原料,采用溶液共混法制备了聚丙烯酸酯-TiO2杂化涂层.采用FT-IR、TEM、UV等方法对杂化涂层进行了测试,并对杂化涂层的光催化性能进行了研究,结果表明:在杂化涂层中聚丙烯酸酯与TiO2通过COO-Ti键发生了化学结合;杂化涂层是较为理想的纳米复合材料,在杂化涂层巾TiO2粒子的粒径分布窄,粒径在3 nm左右;杂化涂层对紫外线的吸收性能明显优于聚丙烯酸酯,杂化涂层对紫外线的吸收发生了红移;与TiO2粉末相比,杂化涂层的光催化速率慢,但光催化得较彻底,随着AA与TiO2物质的量比的增加,杂化涂层对亚甲基蓝的降解率先是增加,然后又减少,降解率可达97%,杂化涂层的重复使用性能良好,便于回收,在污水处理领域具有广泛的实际应用价值.     

聚丙烯酸酯/TiO_2杂化全息记录涂层的研究

采用原位溶胶-凝胶法制备了聚丙烯酸酯(PAEs)/TiO_2杂化激光全息记录涂层,通过激光全息模压制得聚丙烯酸酯(PAEs)/TiO_2杂化涂层激光全息记录材料.对杂化涂层进行了红外、X-衍射结构表征,结果表明:TiO_2以无定形结构均匀分散在PAEs中.杂化涂层具有优异的性能,其玻璃化温度随纳米TiO_2含量的增加而提高,可达到8℃,耐热性得到提高;光泽度有一定程度的提高;激光全息记录材料光栅衍射效率均在1.5以上。     

溶胶-凝胶法制备聚丙烯酸酯/纳米TiO2有机-无机杂化材料的研究

以丙烯酸酯单体为原料,采用常规溶液聚合法制备了聚丙烯酸酯溶液,以钛酸正丁酯为前驱体,水解制备纳米二氧化钛溶胶,两者在常温高剪切力下共混,制得聚丙烯酸酯/纳米TiO2有机-无机杂化材料。分别用透射电子显微镜(TEM),原子力显微镜(AFM),双光束紫外-可见分光光度计UV-VIS,热重分析(TGA),拉伸测试研究了纳米溶胶以及杂化材料的性能。结果表明:TiO2在溶胶和杂化材料中都呈纳米级均匀分散,而且杂化材料的光学,热学,力学性能都比纯聚丙烯酸酯有显著的提高。     

聚丙烯酸酯/TiO2-SiO2纳米杂化材料性能的研究

采用具有核-壳结构的纳米TiO2-SjO2与热固性聚丙烯酸酯原位复合，通过溶胶-凝胶法制得了有机-无机纳米杂化材料，并对材料的结构和性能进行了表征。结果表明：聚丙烯酸酯基纳米SiO2包覆TiO2的有机-无机纳米杂化材料在无机组分质量分数低于8％时是透明的；随着TiO2-SiO2用量的增加，纳米杂化材料的附着力是先增后降，而热稳定性则是逐渐增加；拉伸强度和冲击强度随TiO2-SiO2用量的增加都是先增后降，当TiO2-SiO2质量分数为5．10％时，拉伸强度达到最大值，提高了25％；当TiO2-SiO2质量分数为3．45％时，无缺口冲击强度达到最大值，提高了27％。     

聚丙烯酸酯/ TiO2-SiO2纳米杂化材料的制备与性能研究

用原位复合、溶胶-凝胶法成功制得热固性聚丙烯酸酯基纳米SiO2包覆TiO2的有机-无机纳米杂化材料,通过红外光谱(FT-IR)、透射电镜(TEM)、扫描电镜(SEM)、紫外-可见光谱(UV-Vis)及热失重和差示扫描量热法(TG-DSC)等对材料的结构和性能进行了表征.实验证明了聚丙烯酸酯/TiO2-SiO2纳米杂化材料对紫外线有很好的屏蔽效果及更好的热稳定性.     

静电纺丝法制备Y掺杂ZnO纳米材料及其光催化性能

通过调节前驱液组分,使用电纺丝法和焙烧工艺,制备Y掺杂ZnO纳米颗粒,采用透射电子显微镜、X射线衍射、光致发光光谱、N_2吸附-脱附和XPS等进行表征。结果表明,Y掺杂ZnO材料具有明显的球形结构,与纯ZnO相比,纳米粒径更小,结构更疏松,具有较大的比表面积,晶体材料的禁带宽度相应变窄。光催化污染物降解实验表明,Y掺杂ZnO能够提高ZnO材料的光催化性能,Y掺杂物质的量分数为0.25%时,光催化降解性能最好,表明Y掺杂是一种有效提高ZnO材料光催化性能的改性手段。     

化学复合镀法制备多孔光催化材料及其光催化性能

以多孔泡沫镍为载体,采用化学复合镀法制备了性能优良的多孔光催化材料,以产品对水中罗丹明B的降解性能为评价指标,对产品的光催化性能进行评价. 产品对水中罗丹明B的光催化降解反应严格符合零级动力学规律. 化学复合镀制备多孔光催化材料的最佳工艺条件为：镀液中硫酸镍浓度20 g/L,次亚磷酸钠浓度20 g/L,施镀过程中纳米TiO2投加量0.28 g/L,镀液温度90℃,镀液pH值4.6. 各因素影响产品性能的顺序为硫酸镍浓度>次亚磷酸钠浓度>镀液温度>镀液pH值>纳米TiO2投加量. 纳米Bi2O3复合使产品的光催化性能下降,随着纳米Bi2O3复合量增加,产品的光催化性能提高. ZnO复合使产品的光催化性能有明显改善,随着纳米ZnO复合量的增加,产品的光催化性能提高. Ag修饰导致Bi2O3复合光催化材料的光催化性能下降、ZnO复合光催化材料的光催化性能提高.     

ZnO纳米阵列的制备及其压电效应对丁基钾黄药光降解的促进

采用低温溶液法,以硝酸锌和氨水为原料,在不锈钢网基体上生长ZnO纳米阵列。通过SEM、XRD、UV-Vis DRS和IR等对光催化材料的结构和性能进行测试分析,进一步探讨压电效应对光催化降解丁基钾黄药的促进作用。结果表明,ZnO纳米阵列围绕不锈钢网紧密排列,形貌规整,具有平滑表面,直径(1~2)μm。制备的光催化材料在光照和超声条件下,90 min内对50 mg·L^(-1)丁基钾黄药溶液的降解率可以达到96.36%,降解反应速率常数k为0.0710×10^(-2)min^(-1),是光照条件的2.19倍。机理分析表明,ZnO在紫外线照射下产生光生电子和空穴,同时在超声作用下ZnO纳米棒发生变形产生压电场,压电效应能够促进光生电子和空穴的分离,从而提高ZnO纳米阵列对丁基钾黄药的降解效率。该研究为尾矿废水中黄药的去除提供了一种新的思路,在光催化处理有机污染方面有巨大的应用潜力。     

两种形貌纳米ZnO的制备及其光催化性能测试

在超声辅助下,以醋酸锌、柠檬酸、乙醇和氢氧化钠为原料利用水热合成法成功一步合成纳米氧化锌,通过控制乙醇和柠檬酸的用量来控制纳米ZnO的形貌,得到了球形和花状两种纳米ZnO材料。表征发现:材料具有很好的形貌,XRD图谱分析认为,材料均具有极好的结晶度;并同时从机理方面探讨了不同形貌形成的原因;最后,利用酸性品红在高压汞灯的照射下测试了不同材料的光催化性能。结果表明:该法制备的材料性能稳定,质地均匀,拥有良好的光催化能力。球状的纳米ZnO材料略优于花状纳米ZnO材料的光催化性能,对20mg/L酸性品红溶液的降解率可达93.9%。     

纳米氧化锌的制备方法及其光催化性能

纳米氧化锌（ZnO）作为一种高功能材料,被广泛应用于气体传感、催化、能源、光电材料等领域,在紫外光照射下,可产生光致电子-空穴对,表现出良好的光催化特性,可以提高氧化还原反应的速率,氧化难降解有机物用于污染治理,具有无毒、高效、低成本等优点。综述了近年来纳米氧化锌的制备方法及原理,介绍了其光催化性能的机理和表征方法。提出今后需加强对掺杂纳米ZnO的理论和制备技术研究,加大纳米ZnO薄膜光催化性能的研究,对纳米ZnO进行改性,提高光催化活性,进一步拓宽工业化应用领域。     

ZnO nanocrystallites/cellulose hybrid nanofibers fabricated by electrospinning and solvothermal techniques and their photocatalytic activity

ZnO nanocrystallites have been in situ embedded in cellulose nanofibers by a novel method that combines electrospinning and solvothermal techniques. Zn(OAc)₂/cellulose acetate (CA) precursor hybrid nanofibers with diameter in the range of 160–330 nm were first fabricated via the electrospinning technique using zinc acetate as precursor, CA as the carrier, and dimethylformamide (DMF)/acetone(2 : 1) mixture as cosolvent. The precursor nanofibers were transformed into ZnO/cellulose hybrid fibers by hydrolysis in 0.1 mol/L NaOH aqueous solution. Subsequently, these hybrid fibers were further solvothermally treated in 180°C glycerol oil bath to improve the crystallite structure of the ZnO nanoparticles containing in the nanofibers. The structure and morphology of nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction. It was found that hexagonal structured ZnO nanocrystallites with the size of ～ 30 nm were dispersed on the nanofiber surfaces and within the nanofibers with diameter of about 80 nm. The photocatalytic property of the ZnO/cellulose hybrid nanofibers toward Rhodamine (RhB) was tested under the irradiation of visible light. As a catalyst, it inherits not only the photocatalytic ability of nano‐ZnO, but also the thermal stability, good mechanical property, and solvent‐resistibility of cellulose nanofibers. The key advantages of this hybrid nanofiber over neat ZnO nanoparticles are its elasticity, dimensional stability, durability, and easy recyclability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

热蒸发法制备ZnO微／纳米材料的光催化性能研究

采用简单的热蒸发法,调控温度与催化剂制备了ZnO微／纳米材料,通过扫描电子显微镜（SEM）和X-射线衍射（xRD）对产物的结构和形貌进行了表征,并以甲基橙溶液为光催化反应模型降解物,考察了样品的光催化活性。结果显示,ZnO微／纳米材料为六角纤锌矿结构,Ni（NO3）2催化剂的存在对不同温度下生成的ZnO光催化效率有较显著影响。     

The structure and photocatalytic performances of mechanically synthesized poly(3′,4′‐ethylenedioxy‐2,2′:5′,2″‐Terthiophene)/Zno composites

Poly(3′,4′‐ethylenedioxy‐2,2′:5′,2″‐terthiophene)/ZnO(poly(TET)/ZnO) composites with the ratio of poly(TET) and nano‐ZnO from 3:1 to 1:3 were synthesized by hand grinding and ball milling methods, respectively. The photocatalytic activities of the composites were examined through the degradation processes of methylene blue (MB) solution under UV light irradiation, and the possible mechanism for the photocatalytic activity enhancement by synergetic effects between nano‐ZnO and poly(TET) was proposed. The results showed that the strong interactions between the poly(TET) and nano‐ZnO occurred in the case of ball milling method. The results also proved that the crystallinity of ZnO was not disturbed in both of methods, and the nano‐ZnO was uniformly distributed in polymer matrix in the case of ball milling method. The comparative studies showed that the addition of the nano‐ZnO could enhance the photocatalytic activities of the composites. The highest degradation efficiency (100%) at 3 h under UV light irradiation occurred in the case of poly(TET)/ZnO(1:1) synthesized by ball milling method. Furthermore, the nanocompsosite displayed higher photocatalytic activity than nano‐ZnO, which was due to the holes (h⁺) transferring from the valence band of ZnO to the polymer backbone and the adsorption of MB molecules in polymer matrix via π–π conjugation between MB and aromatic regions of the poly(TET). POLYM. COMPOS., 36:1597–1605, 2015. © 2014 Society of Plastics Engineers     

多壁碳纳米管/硫化铅纳米杂化材料

在经强酸氧化处理的多壁碳纳米管(MWCNT)上修饰以苯环为核心的聚(酰胺-胺)树枝状大分子,然后以树枝状大分子修饰的碳纳米管为模板,在碳纳米管表面原位沉积PbS纳米粒子。用XRD、SEM、TEM和TGA等手段对所得MWCNT/PbS纳米杂化材料进行表征。结果表明,利用这个方法能够使PbS纳米粒子均匀修饰在碳纳米管上,纳米粒子的平均尺寸为6.5 nm。采用开口z扫描技术研究MWCNT/PbS纳米杂化材料在1 064 nm处的非线性光学性质。MWCNT/PbS纳米杂化材料在1 064 nm处的光限幅性能优于未经修饰的碳纳米管。     

Reducing the Photocatalytic Activity of Zinc Oxide Quantum Dots by Surface Modification

The use of zinc oxide (ZnO) nanoparticles as ultraviolet (UV) absorbers for many organic substrates is limited because of the high photocatalytic activity of ZnO. In this study, a facile and efficient technique for the preparation of a hybrid material of silica-coated ZnO nanoparticles was used to reduce the photocatalytic activity of ZnO. Monodispersed ZnO nanopartcles were prepared by wet chemistry and the particle surface was modified by tetraethylorthosilicate to form a silica coating via the Stöber method. ZnO samples, both before and after the coating process, were investigated by transmission electron microscopy, X-ray diffraction, dynamic light scanning, infrared, and UV-Vis absorption spectroscopy. The effect of the surface modification on the photocatalytic activity of ZnO was studied by monitoring the degradation of Rhodamine B caused by photo-generated free radicals. The results implied that the photo-generation of free-radicals was strongly quenched by the presence of silica on the particle surface.     

ZnO纳米晶的光催化还原性能研究

用直接沉淀法合成粒径小于20 nm的氧化锌颗粒,采用XRD和TEM等技术对其进行表征.在其悬浮体系中对CO32-进行光催化还原实验,以光谱分析法测定还原产物甲酸、甲醛和甲醇的含量,研究催化剂的浓度、CO32-浓度、pH值等因素对还原产物产率的影响.结果表明,纳米氧化锌具有较强的光催化还原活性,光激发生成的电子可将CO2转化为甲酸、甲醛及甲醇等基本有机原料.     

Preparation and characterization of bipolar membranes modified using photocatalyst nano‐TiO2 and nano‐ZnO

The nano‐ZnO and nano‐TiO₂ were added into chitosan (CS) anion layer to prepare polyvinyl alcohol (PVA) ‐ sodium alginate (SA)/ TiO₂‐ZnO‐CS (here, PVA:polyvinyl alcohol; SA:sodium alginate) bipolar membrane (BPM), which was characterized using scanning electron microscopy, atomic force microscopy (AFM), thermogravimetric analysis (TG), electric universal testing machine, contact angle measurer, and so on. Experimental results showed that nano‐TiO₂‐ZnO exhibited better photocatalytic property for water splitting at the interlayer of BPM than nano‐TiO₂ or nano‐ZnO. The membrane impedance and voltage drop (IR drop) of the BPM were obviously decreased under the irradiation of high‐pressure mercury lamps. At a current density of 60 mA/cm², the cell voltage of PVA‐SA/TiO₂‐ZnO‐CS BPM‐equipped cell decreased by 1.0 V. And the cell voltages of PVA‐SA/TiO₂‐CS BPM‐equipped cell and PVA‐SA/ZnO‐CS BPM‐equipped cell were only reduced by 0.7 and 0.6 V, respectively. Furthermore, the hydrophilicity, thermal stability, and mechanical properties of the modified BPM were increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

金属氧化物掺杂高岭土纳米 二氧化钛光催化复合材料研究

以高岭石为载体,以钛酸四丁酯为前驱体,采用溶胶-凝胶法制备金属氧化物掺杂高岭土纳米二氧化钛光催化复合材料。采用X射线衍射（XRD）、红外光谱（FT-IR）和拉曼光谱（Raman）对复合材料进行表征,并通过在紫外光下降解云母珠光工业废水来考察其光催化性能。研究了不同金属氧化物掺杂浓度对复合材料光催化活性的影响。实验结果表明：金属氧化物三氧化二铁、氧化锌掺杂使锐钛矿二氧化钛晶相特征衍射峰宽化,掺杂生成钛铁矿、红锌矿新相,影响锐钛矿二氧化钛结晶度。在紫外光下降解6 h,掺杂质量分数为0.5%的三氧化二铁对废水降解率为98.8%,掺杂质量分数为1.5%的氧化锌对其降解率为91.4%。     

High performing photocatalytic ZnO hollow sub-micro-spheres fabricated by microwave induced self-assembly approach

The development of high-performing photocatalytic materials is highly sought after, but challenging, especially for environmental applications. Herein, we report on a microwave induced self-assembly approach for the fabrication of uniform submicron ZnO hollow spheres (ZOHS) with shell walls of nano diameter. This approach is more efficient, greener and swifter than methods that have been previously reported on. The microwave induced self-assembly method is an interesting approach to produce well-defined and uniform ZnO hollow-structured spheres as revealed by TEM, SEM, XRD, IR, TGA and BET analysis. Of particular interest is the practical relevance of the photocatalytic performance of the obtained hollow-structured ZnO was explored through the photodegradation of Rhodamin B (RhB). The ZOHS exhibited higher photocatalytic performance when compared with its solid counterparts (at room temperature) as revealed by UV–Vis analysis.     

Fabrication and properties of nano‐ZnO/glass‐fiber‐reinforced polypropylene composites

Polypropylene (PP) is widely used in many fields, such as automobiles, medical devices, office equipment, pipe, and architecture. However, its high brittle transformation temperature, low mechanical strength, dyeing properties, antistatic properties, and poor impact resistance, considerably limit its further applications. Nano‐ZnO treated by KH550 coupling agent and glass fibers (GFs) were introduced in order to improve the mechanical performance and flowability of PP in this research. The crystallization behavior and microstructure of nano‐ZnO/GFs/PP hybrid composites were analyzed by differential scanning calorimetry, transmission electron microscopy, and scanning electron microscopy. The effect of crystallization behavior on the mechanical properties of the nanocomposites was investigated and analyzed. The results indicated that nano‐ZnO surface‐coupled by KH550 could be uniformly dispersed in the PP matrix. The incorporation of nano‐ZnO and GFs resulted in increases of the crystallization temperature and crystallization rate of PP and a decrease of the crystallization degree. The introduction of nano‐ZnO and GFs also enhanced the tensile strength and impact toughness of the hybrid composites and improved their fluidity. Composites containing 2% of nano‐ZnO and 40% of GFs possessed the optimum mechanical properties. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers