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1.
以1,2-乙二硫醇、四溴双酚A环氧树脂和9,9-二[(2,3-环氧丙氧基)苯基]芴为原料,LiOH的甲醇溶液为催化剂,采用巯基-环氧点击化学反应制备含S和Br元素的聚合物基体;以钛酸四丁酯为前驱体,采用溶胶-凝胶法和分段热固化制备出透明高折射率TiO_2纳米杂化材料。通过红外光谱、纳米粒度仪、椭圆偏振光谱仪、透射电子显微镜和紫外-可见分光光度计等仪器对其结构、性能进行表征。结果表明:TiO_2粒子在聚合物基体中成功合成并以纳米尺度均匀分散,材料在可见光区域有很高的透光率,大多在95%左右;随着TiO2粒子杂化量的增加,在486 nm处的折射率由1.660 2提高到了1.756 5,阿贝数由21.65提高到34.63。  相似文献   

2.
利用硅烷偶联剂KH570对TiO2纳米粒子进行表面改性,然后制备塑化超高分子量聚乙烯(PE-UHMW)/TiO2复合材料,最后通过密炼-模压法制备不同含量和粒子尺寸的TiO2纳米粒子增强PE-UHMW/高密度聚乙烯(PE-HD)复合材料。通过扫描电子显微镜、透射电子显微镜、差示热扫描量热仪、万能试验机、流变仪表征测试复合材料的微观结构、结晶、力学及流变性能。结果表明,低含量的Ti O2纳米粒子(质量分数0.1%)能在聚合物基体中分散良好,使复合材料的力学性能、结晶度及流动性均有显著提升;随粒子尺寸增加,材料强度和刚度降低,断裂伸长率和熔体剪切黏度先增加后降低。然而,高含量粒子分散困难、易形成大的聚集体,导致复合材料性能下降。当TiO2纳米粒子尺寸为5~10 nm、质量分数为0.1%时,复合材料展现出优异的力学性能和加工性能,拉伸强度和拉伸屈服强度分别高达58.21 MPa和44.53 MPa,且熔体剪切黏度下降19.7%。  相似文献   

3.
以自制的端异氰酸酯基聚丁二烯(ITPB)为基体,纳米二氧化硅(SiO2)为交联固化剂,采用预聚体法制备了一系列不同纳米SiO2含量的有机-无机杂化材料。阐述了其制备机理,研究了不同固化条件对有ITPB/SiO2杂化材料力学性能的影响,并对其进行了动态力学分析和X射线衍射分析。结果表明:室温固化14 d后,110℃固化24 h,杂化材料的综合力学性能最佳。纳米SiO2的添加量越多,杂化材料的储能模量越大。添加质量分数12%的纳米SiO2杂化材料的抗湿滑性能和操控性能最好,纳米SiO2添加质量分数为8%时,杂化材料的滚动阻力最小。  相似文献   

4.
那沙沙  李卫星  邢卫红 《化工学报》2016,67(9):3730-3737
为提高海藻酸钠(SA)膜的渗透汽化分离性能,分别采用纳米氧化铝、纳米氧化锆和纳米氧化钛对SA膜进行改性,对比分析了3种不同杂化膜渗透汽化分离性能的差异,并将分离性能较好的杂化膜应用到乙酸与乙醇酯化反应脱水的体系中。系统考察了无机纳米粒子含量对SA膜渗透汽化分离性能的影响,对杂化膜进行了接触角、傅里叶红外(FTIR)、扫描电子显微镜(SEM)、热重/差示扫描量热(TG/DSC)、X射线衍射(XRD)和拉伸强度等表征与分析。结果表明,无机纳米粒子能提高SA膜的热稳定性、机械强度和渗透通量,当无机纳米粒子与SA质量比为0.3时,掺杂TiO2、ZrO2和Al2O3的杂化膜二碘甲烷的接触角依次升高,同时渗透通量也依次升高。SA-0.3Al2O3杂化膜亲水性较好,然而SA-0.3ZrO2杂化膜分离性能最优,50℃下分离水含量10%的乙醇-水溶液,膜渗透通量达到336 g·m-2·h-1,渗透侧水含量99.97%,分离因子29990。酯化反应脱水实验表明,在80℃时,酯化反应脱水实验乙酸转化率均高于无脱水实验乙酸转化率,平衡转化率不断被打破,反应12 h后,转化率由平衡时的79.3%提高到93.9%。  相似文献   

5.
通过溶胶-凝胶法在金红石型纳米二氧化钛(TiO2)表面包覆二氧化硅(SiO2)薄膜,对纳米TiO2进行表面改性。通过优化聚乙烯吡咯烷酮(PVP)用量、硅钛比、氨水的用量确定最佳制备条件为:TiO2用量为0.3 g,PVP用量为0.4 g,硅钛比为2∶1,氨水用量为5 m L,获得了粒径小,SiO2包覆层薄,单分散性好的SiO2-TiO2复合纳米粒子。应用FT-IR,XRD,SEM,TEM和UV-vis等对改性前后的粒子进行表征。结果表明:红外光谱图中出现Si-O-Ti键的振动吸收峰,改性前后的纳米TiO2均为金红石型,SEM及TEM显示改性后的粒子团聚现象减弱,其表面形成了约10 nm的SiO2薄膜。经过表面改性,SiO2成功包覆在纳米TiO2表面,复合纳米粒子的光催化活性得到有效抑制,纳米TiO2作为防晒剂的安全性大大提高。...  相似文献   

6.
王晓娟  毛信表  李国华  马淳安 《化工学报》2016,67(11):4873-4877
以金红石相纳米TiO2为载体,偏钨酸铵为钨源,采用表面修饰技术制备了纳米复合材料的前体,将前体在甲烷/氢气气氛下还原碳化并采用XRD对其进行表征,研究了还原碳化温度、时间对纳米复合材料晶相组成的影响,并探讨了WC/TiO2纳米复合材料的形成机理。通过扫描电子显微镜、热重-差热分析等手段对WC/TiO2纳米复合材料的形态结构和热稳定性进行了表征。采用循环伏安法研究了纳米复合材料物相组成与电催化性能之间的关系,结果表明由WC和TiO2两相组成的WC/TiO2纳米复合材料对对硝基苯酚电还原反应的电催化性能最佳。  相似文献   

7.
分别以粉煤灰漂珠(简记为FACs)与海胆状莫来石球(简记为Mullite)为基体,采用溶胶浸渍工艺制备了TiO2/FACs与TiO2/Mullite型复合材料。通过X射线衍射(XRD)、扫描电子显微镜(SEM)以及电子能谱(EDS)对制备的材料进行了表征。研究了TiO2/FACs与TiO2/Mullite型复合材料在紫外光照射下对罗丹明B(RhB)的光催化性能。结果表明:经500℃煅烧后形成的锐钛矿型TiO2均成功负载到粉煤灰漂珠与莫来石晶体上,在粉煤灰漂珠表面覆盖了一层厚薄不均的纳米级别的TiO2薄膜,而在莫来石晶体上则出现了大量细小的TiO2颗粒;在降解染料时间为180 min,TiO2/FACs与TiO2/Mullite复合材料对罗丹明B染料的降解率分别为84.8%和96.4%,降解速率为0.01088min-1和0.02885 min-1。  相似文献   

8.
将纳米二氧化钛(TiO2)粒子与4类制膜添加剂复配处理,采用相转化法制备聚偏氟乙烯(PVDF)-TiO2复合中空纤维膜,讨论了纳米TiO2粒子对复合膜结构和性能的影响。通过扫描电子显微镜、X射线衍射、能谱分析、热重分析、拉伸试验、接触角测定和超滤实验分别表征了复合膜的微观孔结构、晶相结构和复合均匀性、热稳定性、机械性能、亲水性、超滤性能以及抗污染性能。结果表明:通过添加TiO2粒子复配添加剂,复合膜的性能得到有效改善。复配添加剂中w(TiO2)为2%(占PVDF固含量的质量分数)时,纯水通量由348 L/(m2·h)提高至377 L/(m2·h),牛血清蛋白截留率由68%提高至90%,断裂强度和抗污染性能提高,复合膜综合性能优异。  相似文献   

9.
通过水热法合成TiO2/GO复合纳米材料,在Q235碳钢表面制备了一系列TiO2/GO/EP复合涂层,并对复合材料进行结构表征,探究不同含量GO对复合涂层光电化学防腐性能的影响。结果表明:TiO2/GO纳米复合材料在紫外光和可见光区域吸收强度有明显提升;不同配比的TiO2/GO/EP复合涂层都具有光电响应和光致阴极保护效果,其中,TiO2/GO/EP-3复合涂层的光电响应最明显,光电流密度为0.003 8 A/cm2,光电压降至-681 mV。在环氧树脂中添加纳米复合粒子后涂层的耐水性、耐碱性更优,耐酸性有所改善,硬度和附着力明显增大,可对Q235碳钢基体提供良好的涂层屏蔽保护和半导体光生阴极保护作用。  相似文献   

10.
姚彦虎  杨晨  张兵  吴永红  王同华 《化工学报》2021,72(8):4418-4424
以聚酰亚胺为前体,TiO2溶胶为掺杂剂,经成膜和炭化制得杂化炭膜。采用热失重、电子显微镜、X-射线衍射、红外光谱和渗透法对前体的热性能、炭膜的微观形貌、微结构、表面官能团和气体分离性进行了表征。考察了TiO2溶胶用量、渗透温度和渗透压力对炭膜的结构与性能影响。结果显示,掺杂TiO2溶胶显著提高了最终炭膜渗透性和选择性;采用TiO2溶胶量为10%前体所制备的杂化炭膜对H2、CO2、O2渗透性分别为1993.8、1555.6、266.9 Barrer,同时H2/N2、CO2/N2、O2/N2选择性分别为93.6、73.0、12.5。  相似文献   

11.
Photocatalytic decomposition of 4-nitrophenol on Ti-containing MCM-41   总被引:1,自引:0,他引:1  
A series of Ti-containing MCM-41 samples, such as Ti-MCM-41 with variable Si/Ti ratios and Cr–Ti-substituted TiO2-loaded MCM-41 having different TiO2 loading, were prepared and studied for the photocatalytic decomposition of 4-nitrophenol in UV and visible light. The samples were characterized using surface area measurement, XRD, FT-IR, and UV–vis DRS techniques. In the case of the Ti-MCM-41 samples with Si/Ti ratios higher than 20 which were found to have typical mesoporous structure, the framework incorporation of Ti into MCM-41 increased with decreasing Si/Ti ratio. On the contrary, the Ti-MCM-41 with lower Si/Ti ratio (Si/Ti = 10) shows low structural integrity and the formation of Ti-oxide species, leading to a considerable decrease in surface area. In the case of Cr–Ti-substituted TiO2-loaded MCM-41 samples, significant absorption occurs in visible light and the absorption in both UV and visible region increases with increasing TiO2 loading. However, when the amount of TiO2 loaded on Cr–Ti-MCM-41 increased above 33 wt.%, the absorption in visible light increased slightly. Thus, it seems that, at higher TiO2 loading, some TiO2 particles are not closely bound to the wall of Cr–Ti-MCM-41. The photocatalytic activities of Ti-containing MCM-41 samples were strongly influenced by the amount of Ti. Under UV illumination, the highest photocatalytic activity for photocatalytic decomposition of 4-NP was observed for the Ti-MCM-41 having Si/Ti ratio of 20. Among various Ti-containing MCM-41 materials prepared in this work, only Cr–Ti-substituted TiO2-loaded MCM-41 catalysts exhibited discernable photocatalytic activities in visible light, and their photocatalytic activities increased considerably with increasing TiO2 loading up to 33 wt.%. Further increase in TiO2 loading enhanced photocatalytic activity slightly.  相似文献   

12.
TiO2 nanocrystalline particles dispersed in SiO2 have been prepared by the sol-gel method using titanium- and silicon-alkoxides as precursors. Nano-composite thin films were formed on the glass substrates by dip-coating technique and heat treated at temperatures up to 500 °C for 1 h. The size of the TiO2 nanocrystalline particles in the TiO2–SiO2 solution ranged from 5 to 8 nm. The crystalline structure of TiO2 powders was identified as the anatase phase. As the content of SiO2 increased, the anatase phase tended to be stabilized to higher temperature. TEM results revealed the presence of spherical TiO2 particles dispersed in a disk-shaped glassy matrix. Photocatalytic activity of the TiO2–SiO2 (1:1) thin films showed decomposition of 95% of methylene blue solution in 2 h and a contact angle of 10°. The photocatalytic decomposition of methylene blue increased and the contact angle decreased with the content of TiO2 phase. TiO2–SiO2 with the molar ratio of 1:1 showed a reasonable combination of adhesion, film strength, and the photocatalytic activity.  相似文献   

13.
Nanosized TiO2 particles were prepared by hydrothermal method of the amorphous powders which were precipitated in an aqueous peroxotitanate solution using different amine group-containing organics. The physical properties of prepared nanosized TiO2 particles were investigated. We also examined the activity of TiO2 particles as a photocatalyst for the decomposition of orange II. The TiO2 particles calcined at 400 °C were shown to have a stable anatase phase which has no organic compounds. The particles size of titania particles decreased from 15 to 10 nm as the carbon chain length increased. The titania nanoparticles were shown to have a polygonal shape prepared using NH4OH and tetramethylammonium hydroxide (TMAOH) as additives, however, the micrographs showed the spherical and narrow size distribution prepared using tetraethyl-ammonium hydroxide (TEAOH) and tetrabutylammonium hydroxide (TBAOH). The titania particles prepared using TEAOH as an amine group-containing organic showed the highest activity on the photocatalytic decomposition of orange II. In addition, the titania particles calcined at 500 °C showed the highest activity on the photocatalytic decomposition of orange II.  相似文献   

14.
夏振国  朱颖颖  陈耿  卢宇  王家锋 《化工进展》2021,40(7):3837-3846
二氧化钛(TiO2)在光照下可以产生具有强氧化性能的活性基团,活性炭(AC)具有良好的吸附性能。将TiO2负载在AC上制备的TiO2/AC复合材料可以有效去除大部分难降解的有机污染物,因此在环境净化领域具有良好的应用前景。本文综述了TiO2/AC复合材料的研究现状,介绍了目前TiO2/AC复合材料的三种主要制备工艺:溶胶-凝胶法、溶剂热法和微波合成法。其中溶胶-凝胶法所制备的材料稳定性好、溶剂热法制备条件温和、微波合成法制备周期短。针对TiO2/AC复合材料可见光吸收率低和量子利用率低等问题,介绍了离子掺杂、半导体复合、贵金属沉积等现有的TiO2/AC复合材料改性方法。之后,概述了所制备的TiO2/AC复合材料在去除难降解有机污染物(染料废水、药物类、酚类、挥发性有机物)中的应用。最后展望了TiO2/AC复合材料在改性研究与实际应用过程中存在的挑战性问题及可行的解决方法,为TiO2/AC复合材料深入研究和大规模工业生产应用提供参考。  相似文献   

15.
Mesoporous TiO2 film photocatalysts supported on stainless steel substrates were prepared using the sol–gel method with Ti(OC4H9)4 as a precursor and poly ethylene glycol (PEG) as a structure-directing agent. Mesoporous TiO2 film with a pore diameter of about 15 nm was obtained with the addition of PEG (molecular WEIGHT =400). The pore diameter of TiO2film was varied with molecular weight of PEG additive. The structure-directing process was also discussed. Mesoscopically ordered inorganic/polymer composites were believed to form during the process. Compared to conventional TiO2 film photocatalyst, the mesoporous TiO2 film showed a good performance for the photo degradation of rhodamine B (RB) solution irradiated with UV light of 365 nm. The photo degradation constant of rhodamine B for mesoporous TiO2 film photocatalyst can arrive at 22 times of that for conventional TiO2 film photocatalyst. Also an excellent performance for the degradation of gaseous formaldehyde with mesoporous film photocatalyst was obtained. The photo degradation rate of gaseous formaldehyde for mesoporous TiO2 film photocatalyst can arrive at six times of that for conventional TiO2 film photocatalyst.  相似文献   

16.
胆红素是一种内源性毒素,当人体肝脏系统受损或代谢受阻时,则在体内累积,引起高胆红素血症,其具有神经毒性,严重时甚至会危及生命。无机纳米材料作为胆红素吸附剂越来越受到关注,但也存在因团聚而吸附效率降低、因颗粒过小而容易泄漏的问题。以聚偏氟乙烯(PVDF)为基膜原料,掺杂纳米TiO2颗粒,DMAc为溶剂、PVP为致孔剂,通过干湿相转化法,制得TiO2/PVDF共混微滤膜。当铸膜液中PVDF浓度为10%(质量)、TiO2含量为1%(质量)、PVP含量为6%(质量)时,制备的TiO2/PVDF共混微滤膜的胆红素特异性吸附显著。电镜照片及EDX能谱发现,该膜内部及孔隙中均匀分布TiO2颗粒,颗粒无团聚现象。实验还考察了胆红素初始浓度、吸附时间、吸附温度、pH等吸附条件的影响。  相似文献   

17.
张崇淼  温银梅  高敏  高倩 《化工进展》2018,37(11):4343-4348
氧化物具有化学性质稳定、原材料丰富易得的优点,其作为抗菌材料日益受到关注。对氧化物的抗菌性能及影响因素开展深入研究,能够为新型抗菌材料的开发提供科学依据。通过溶胶-凝胶法制备出了TiO2/ZnO复合粉体,并将其与TiO2、ZnO进行对比,分别对它们的晶相结构、微观形貌和粒径进行了表征。利用大肠杆菌ATCC25922作为受试菌株,通过抑菌环试验和菌液接触试验对3种氧化物粉体材料的抗菌性能进行测试。考察了钛锌比、光照等条件对抗菌效果的影响。结果表明,所使用的TiO2主要由锐钛矿相和金红石相组成,ZnO主要为六方纤锌矿相,制备出的TiO2/ZnO则主要是锐钛矿型TiO2在六方纤锌矿型ZnO的孔隙间沉积而成,这3种粉体材料的粒径由大到小分别为TiO2/ZnO、TiO2和ZnO。从抑菌环和菌液接触试验的结果可以看出,ZnO粉体材料的抗菌效果明显优于TiO2粉体材料,ZnO和TiO2/ZnO在黑暗条件下仍有良好的抗菌性能,但在可见光照射条件下抗菌效果更佳。ZnO含量是TiO2/ZnO复合材料抗菌性能的关键因素。制备TiO2/ZnO粉体材料时的煅烧温度对其抗菌性能没有明显影响。  相似文献   

18.
N-doped TiO2 nanoparticle photocatalysts were prepared through a sol-gel procedure using NH4C1 as the nitrogen source and followed by calcination at certain temperature. Systematic studies for the preparation parameters and their impact on the structure and photocatalytic activity under ultraviolet (UV) and visible light irra-diation were carried out. Multiple techniques (XRD, TEM, DRIF, DSC, and XPS) were commanded to characterize the crystal structures and chemical binding of N-doped TiO2. Its photocatalytic activity was examined by the deg- radation of organic compounds. The catalytic activity of the prepared N-doped TiO2 nanoparticles under visible light (λ〉400nm) irradiation is evidenced by the decomposition of 4-chlorophenol, showing that nitrogen atoms in the N-doped TiO2 nanoparticle catalyst are responsible for the visible light catalytic activity. The N-doped TiO2 nanoparticle catalyst prepared with this modified route exhibits higher catalytic activity under UV irradiation in contrast to TiO2 without N-doping. It is suggested that the doped nitrogen here is located at the interstitial site of TiO2 lattice.  相似文献   

19.
The application of metal ion-implantation method has been made to improve the electronic properties of the TiO2 photocatalyst to realize the utilization of visible light. The photocatalytic properties of these unique TiO2 photocatalysts for the purification of water have been investigated. By the metal ion-implantation method, metal ions (Fe+, Mn+, V+, etc.) are accelerated enough to have the high kinetic energy (150 keV) and can be implanted into the bulk of TiO2. TiO2 photocatalysts which can absorb visible light and work as a photocatalyst efficiently under visible light irradiation were successfully prepared using this advanced technique. The UV-Vis absorption spectra of these metal ion-implanted TiO2 photocatalysts were found to shift toward visible light regions depending on the amount and the kind of metal ions implanted. They were found to exhibit an effective photocatalytic reactivity for the liquid-phase degradation of 2-propanol diluted in water at 295 K under visible light (λ>450 nm) irradiation. The investigation using XAFS analysis suggested that the substitution of Ti ions in TiO2 lattice with implanted metal ions is important to modify TiO2 to be able to adsorb visible light.  相似文献   

20.
李静  张启俭  齐平  韩丽  邵超 《工业催化》2017,25(6):19-23
二甲醚是一种理想的氢载体,可用于解决氢的储存和运输。以Pt/TiO_2为部分氧化催化剂,结合Ni/Al_2O_3重整催化剂,考察钛前驱体和焙烧温度对二甲醚部分氧化重整制氢反应的影响。结果表明,以Ti(C4H9O)4为原料制备的TiO_2为金红石相,Ti(SO4)2或Ti O(OH)2为原料制备的TiO_2为锐钛矿相;以Ti(C4H9O)4为原料制备的Pt/TiO_2-E催化剂催化性能略好,转化率接近100%,H2收率约90%,表明金红石相TiO_2负载的Pt催化剂略佳;以Ti(SO4)2为原料制备的Pt/TiO_2-S催化剂500℃焙烧可获得金红石相TiO_2。与Pt/Al_2O_3催化剂相比,Pt/TiO_2催化剂具有更好的催化性能,H2收率超过90%,而Pt/Al_2O_3催化剂H2收率约80%。  相似文献   

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