紫外光辐照有机硅氧烷水解行为的荧光探针法监测

为揭示紫外光辐照对有机硅氧烷加速水解的作用,以芘为荧光探针,分别对紫外光照及非光照条件下3种有机硅氧烷酸水解体系进行了跟踪检测。荧光光谱对比发现:紫外光辐射条件下,在具有明显疏水性取代基硅氧烷水解缩合反应前期,出现明显且不断增长的荧光探针芘的基激缔合物特征发射峰;在具有较弱疏水性取代基硅氧烷水解缩合反应前期,出现明显且不断降低的芘单体特征发射峰;而在非光照条件下,上述相应有机硅氧烷荧光特征峰变化缓慢。结果表明,紫外光辐照不仅对有机硅氧烷水解具有明显促进作用,而且也因此引起分子簇集行为明显变化,这些作用对其溶胶-凝胶过程产生影响。     

特征参量法：（I）二级反应的热动力学研究

通过对热动力学体系特征参量－冷却常数的测定，建立了等浓度和不等浓度二级反应的热动力学研究法－特征参量法，应用该法研究了环氧氯丙烷与碘化钾在磷酸盐缓冲容液中（ｐＨ为７．０２）的开环反应，苄基氯与氢氧化钠的体积分数８０％二甲亚砜－水混合溶剂中的取代反应，苯甲酸乙酯在质量分数５０％乙醇－水混合溶剂中的皂化反应，丙酸乙酯在质量分数８５％乙醇－水混合溶剂中的皂化反应的热动力学，各反应速率常数的计算结果同文献     

特征参量法

通过对热动力学体系特征参量——冷却常数的测定，建立了等浓度和不等浓度二级反应的热动力学研究法——特征参量法．应用该法研究了环氧氯丙烷与碘化钾在磷酸盐缓冲溶液中（ｐＨ为７．０２）的开环反应，苄基氯与氢氧化钠在体积分数８０％二甲亚砜－水混合溶剂中的取代反应，苯甲酸乙酯在质量分数５０％乙醇－水混合溶剂中的皂化反应，丙酸乙酯在质量分数８５％乙醇－水混合溶剂中的皂化反应的热动力学，各反应速率常数的计算结果同文献值吻合，从而验证了该方法的正确性     

酶法制取栀子红色素研究报告

栀子果实的醇提液经碱、酸处理后,将其中的藏花素沉淀出来,得到含栀子苷酸的上清液。在β-糖苷酶的作用下,京尼平酸和含氮物质(如氨基酸、蛋白质、有机铵化合物等)反应,生成栀子红色素。其最大吸收波长在528nm附近。     

己二酸二乙酯合成中的微波催化行为研究

在微波催化下,己二酸和乙醇为主要原料合成了己二酸二乙酯采用正交设计法对反应条件进行了优化,找出了最佳反应条件,并对反应时间、微波辐射强度、酸醇比等因素对产量的影响进行了讨论.     

N-Fe掺杂TiO_2催化剂的研制及其对气相丙酮的光催化消除

采用溶胶凝胶法制备了N-Fe掺杂TiO2催化剂.用X光电子能谱(XPS),紫外漫反射(DRS)等方法对其进行表征.以丙酮为催化底物,测试了N-Fe掺杂TiO2催化剂分别在可见光和紫外光照射下对丙酮光催化消除反应的反应性能.结果表明:在反应温度为66℃,0.15 g的催化剂上,在可见光照下可将初始浓度为0.76 g/m3,流速为10 mL/min的丙酮100%消除;在反应温度为50℃,紫外光照射下可将初始浓度为0.89 g/m3,流速为15 mL/min的丙酮100%消除.并研究了N-Fe掺杂TiO2催化剂紫外光催化消除丙酮反应的动力学,确认光催化反应为一级动力学反应,在反应温度范围内得光催化反应的Ea=18.17kJ/mol,相关系数R2=0.99309.     

胶束溶液中正脂肪酸乙酯的皂化反应

在２０℃和３０℃下，用热动力学面积差法（两点法）研究了极性聚合物（聚乙二醇）、ＣＡＴＢ阳离子表面活性剂及其混合胶束对乙酸乙酯皂化反应的影响；在３０℃下研究了短链醇（乙醇）与ＳＤＳ阴离子表面活性剂混合胶束对正丙酸乙酯皂化反应的影响。结果表明：单一和混合胶束对正脂肪酸乙酯的皂化反应有较强的禁阻作用。还讨论了禁阻作用的原因。     

丁二酸氧钒和己二酸氧钒的热分解反应及V_4C_3催化活性研究

研究了丁二酸氧钒和己二酸氧钒在Ar气氛下的热分解反应。求出了二酸氧钒的热分解反应表观动力学参数n-1.82,E=367.1kJ/mol,logZ=24.25;已二酸氧钒的n=1.06,E=242.9kJ/mol,logZ=15.61。在微型催化床上研究,证明热分解产物V_4C_3对N_2O和NO的热分解具有明显的催化活性。     

羰基硫的光氧化反应研究

以熔凝紫外灯作为光源，利用FT—IR、怀特池、GC—MS、XPS等技术考察了COS与O2混合体系中COS的光氧化反应情况．结果表明，在紫外光照射下，COS能迅速光氧化分解，主要产物有CO2和SO2，光化学反应产生的部分SO2进一步氧化，以SO4^2-的形式大量存在．COS在紫外光光照下的光氧化反应遵循一级反应动力学规律，反应表观速率常数达10^-4～10^-3s^-1.O2的分压对COS光氧化速率有影响，随着氧量的增加，COS光氧化速率的增长逐渐趋于平缓．这为在光的作用下，大气中COS通过光化学反应形成SO2，形成硫酸盐气溶胶提供了实验依据．     

微波辐射合成己二酸二乙酯

推荐一个基础有机化学实验一微波辐射合成己二酸二乙酯,即利用微波辐射技术,在常压下以己二酸和无水乙醇为原料快速合成己二酸二乙酯;考察了微波辐射功率、辐射时间、催化剂用量及反应物料比对反应产率的影响。结果表明：用微波替代传统加热后,能显著缩短酯化反应时间,提高合成效率。学生实验最佳方案为：以0．3mL浓硫酸为催化剂、微波辐射功率700W、反应时间10min、酸醇比为1：8时,己二酸二乙酯的产率为90．2％。     

Crocin Synthesis Mechanism in Crocus sativus

Saffron （Crocus sativus） cells can synthesize crocin, crocetin digentiobiosyl ester, in suspension cultures. The crocin family biosynthesis mechanism was studied using high pressure liquid chromatography （HPLC） to determinate the glucosyltransferase activity and to develop a method for synthesizing medicine from saffron cells. Previous studies indicated that two glucosyltransferases might be involved in the formation of crocetin glucosyl- and gentiobiosyl-esters. GTasel formed an ester bond between crocetin carboxyl groups and glucose moieties while GTase2 catalyzed the formation of glucosidic bonds with glucosyl ester groups at both ends of the molecule. These enzymes can catalyze the formation of crocetin glucosides in vitro. GTasel activity is higher during the first four days of crocin glucosides biosynthesis, but decreases after four days. The formation and accumulation of crocin increase during the first six days and stabilized on the eighth day.     

TiO_2悬浆体系光催化降解苯酚的研究

以高压汞灯为光源,研究了TiO2悬浆体系光催化降解苯酚的动力学规律,并考察了苯酚初 始质量浓度、催化剂投加量、溶液pH值、光强等对苯酚光解速率的影响.研究结果表明:该反应过 程可以用Langmuir-Hinshelwood(L-H)动力学方程描述;在一定条件下,催化剂的投加量、溶液 pH值均存在一最佳值;各因素对光催化降解苯酚反应影响的重要性排列顺序是,光照时间>pH 值>光照强度>TiO2投加量.     

Preparation and photocatalytic properties of ilmenite NiTiO<Subscript>3</Subscript> powders for degradation of humic acid in water

The powders of ilmenite structure NiTiO₃ were prepared by a modified Pechini process using tetrabutyl titanate and nickel acetate as raw materials, and using citric acid and ethanol as a chelating agent and a solvent respectively. The powder samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA) and X-ray diffraction (XRD). The photocatalytic activity of NiTiO₃ under the irradiation of ultraviolet rays (UV) light was evaluated by degrading humic acid (HA) in water as a probe reaction. The possible photodegradation mechanism was studied by the examination of active species ·OH, ·O₂⁻, and holes (h⁺) through adding scavengers. The TG-DTA and XRD results indicated that the good crystal structure of ilmenite phase NiTiO₃ could be obtained when the Ni-Ti citrate complex was calcined at 600°C. The photocatalytic activity experiments indicated that NiTiO₃ had favourable photocatalytic activity under the irradiation of UV light, and the photocatalytic degradation rate of HA reached 95.3% after a 2.5 h reaction with the photocatalyst calcined at 600°C and a photocatalyst dosage of 0.4 g/L. The possible photocatalytic mechanism was deduced that holes (h⁺) and ·OH radicals are the major reactive active species in the photocatalytic reaction, and dissolved oxygen plays a weak role in the degradation of HA.     

一种新型环氧磷酸酯的合成和表征

以氯磷酸二乙酯、3-环己烯-1-甲醇为原料,首先合成3-环己烯-1-甲酯缩磷酸二乙酯(CDP),然后在CDP的基础上合成3-氧化环己烯-1-甲酯缩磷酸二乙酯(OCDP).通过正交实验找出两步反应的较优条件.当反应温度为80℃,n(氯磷酸二乙酯)∶n(3-环己烯-1-甲醇)∶n(三乙胺)=1∶1.5∶1,反应时间为36h时,CDP收率可达80.6%.当反应温度为80℃,n(CDP)∶n(过氧单磺酸钾)∶n(四丁基溴化铵)=1∶2∶1,反应时间为36h时,最终产物OCDP的收率为87.6%.通过红外光谱以及核磁共振分别对两步产物的结构进行表征.     

三丁基氯化锡紫外光催化降解的初步研究

本文报导了三丁基氯化锡的紫外光催化降解反应。降解过程是一个一级动力学反应。反应速率受催化剂用量、光照度、反应ｐＨ值及反应液中的溶解氧含量等因素的影响。其中，催化剂用量和光照度是主要的影响因素。三丁基氯化锡的光催化降解产物为二丁基锡及无机锡。     

光降解法制备聚苯胺纳米棒的研究

采用高聚物聚乙烯醇(PVA)存在下的现场聚合法制备了可溶性的聚苯胺(PANI),并利用高压静电纺丝手段获得了PANI-PVA/TiO2的微米纤维毯.使用电子扫描电镜(SEM)、紫外-可见光谱、红外光谱等手段对样品进行了表征.以TiO2为催化剂,研究了PANI-PVA/TiO2微米纤维毯在254 nm光照射下的催化降解过程,同时探讨并给出了可能的光催化降解PVA的反应机理.结果表明,经过64 h的紫外光照射,PANI-PVA/TiO2中的PVA已基本分解,最终获得了PANI的纳米棒.     

Photocatalytic degradation of metronidazole in aqueous solution by niobate K<Subscript>6</Subscript>Nb<Subscript>10.8</Subscript>O<Subscript>30</Subscript>

The photocatalytic degradation of antibiotic metroni-dazole in aqueous solution by niobate K6Nb10.8O30 photocatalyst that was prepared using a soft-chemical method was studied by Fourier transform infrared spectroscopy and UV-Vis absorption spectrum. Metronidazole is very stable and is difficult to degrade under UV irradiation. K6Nb10.8O30 photocatalyst cannot degrade metronidazole without UV irradiation and shows very high photo-catalytic activity for the degradation of metronidazole under UV irradiation. The photocatalytic degradation rate of metronidazole increased with increasing the dosage of K6Nb10.8O30 photocatalyst. The photocatalytic degradation reaction of metronidazole by nio-bate K6Nb10.8O30 follows the first-order kinetic equation.     

Template/surfactant free and UV light irradiation assisted fabrication of Mn-Co oxides composite nanorings: Structure and synthesis mechanism

A facile, green, cost effective, and template or surfactant free strategy via a two-step route i.e. UV irradiation followed by dissolution-growth for the controlled synthesis of Mn-Co composite nanorings at room temperature was proposed. The nanorings structures and the process were systematically studied via TEM, HRTEM, EDX and XRD. Bir-MnO_2 nanosheets first formed through the direct photolysis of KMnO_4 under UV light irradiation. This was followed by a dissolution-growth process via the dissolution of Bir-MnO_2 nanosheets by the generated H~+ from the redox reaction between the added Co(NO_3)_2 and residual KMnO_4, as well as the accompanied formation of CoOOH, and Mn-Co composite nanorings. It was found that a balance between the dissolution and growth rate was needed. Suitable pH, KMnO_4 presence and the starting nanosheets like Bir-MnO_2 were the key factors for the formation of nanorings. The obtained Mn-Co nanorings/TiO_2 showed enhanced efficiency for the catalytic oxidation of HCHO. Based on the above understandings, it is believed that the developed dissolution-growth method can be adopted for the designing and preparation of other Mn-Co composite nanostructures which can be further applied for environmental pollution remediation.     

强化光催化氧化苯甲酸研究

 研究了不同浓度TiO2、O3、H2O2光催化氧化苯甲酸的过程．结果表明：苯甲酸在光催化臭氧-过氧化氢氧化（UV/TiO2/O3/H2O2）和光催化臭氧氧化（UV/TiO2/O3）过程的浓度去除率比单独光氧化（UV）、光催化氧化（UV/TiO2）、光催化过氧化氢氧化（UV/H2O2）过程明显增高．TiO2的最佳投加量为4.0 g/L，苯甲酸降解速度随着O3浓度增加而增大，低浓度的H2O2能促进苯甲酸氧化．动力学研究表明，苯甲酸降解过程遵循一级反应，苯甲酸在UV/TiO2/O3/H2O2作用下降解的速率常数是UV/TiO2/O3过程的1.47～6.29倍，是UV/TiO2过程的3.39～5.21倍．     

花岗石的致色原因与褪变色机理

通过对花岗石材进行加热、阳光照射、紫外线和6 0 Co辐照等实验 ,研究了它们的褪变色规律 .根据能带理论 ,结合实验结果探讨了花岗石的褪变色机理 ,提出花岗石褪变色现象的利用与防护建议 .