添加剂对有机颜料光催化降解的影响

本文研究了添加(NH4)2S2O8,H2O2以及表面活性剂十二烷基苯磺酸钠(DBS)时,对TiO2光催化降解颜料艳红6B的影响。(NH4)2S2O8的加入可提高水溶性差的颜料艳红6B的降解速度,以酸性及中性条件较适宜。H2O2的加入可提高6B的降解速度,并且TiO2／UV／H2O2要比TiO2／UV或者H2O2／UV体系有效得多,可提高TiO2的重复使用次数及H2O2的利用率。阴离子型表面活性剂DBS的加入降低了6B的降解速度,但在酸性和碱性条件下,6B的降解较中性条件快;DBS的降解在中性条件下较好;二者存在密切的共降解关系。随着表面活性剂DBS浓度的增加,颜料艳红6B和DBS的降解速率均减慢     

TiO_2协同K_2S_2O_8光催化降解碱性橙的研究

以TiO_2/K2S2O8为催化剂,以碱性橙为目标降解物,研究TiO_2协同K2S2O8的紫外光催化降解反应,通过对比TiO_2/K2S2O8和纯TiO_2在紫外灯光照下碱性橙的降解效果,来探究TiO_2协同K2S2O8光催化降解碱性橙的可行性。重点考察了K2S2O8的浓度、碱性橙的不同初始浓度、p H值和光照时间等因素从而确定碱性橙的最佳降解条件。实验结果表明:当碱性橙的初始浓度为10 mg/L,TiO_2的用量为1.0 g/L,K2S2O8的用量为0.5 g/L,p H为6.7,紫外灯光照降解碱性橙溶液50min的条件下,碱性橙的降解率可达95.71%。通过比较得出,在最佳条件下TiO_2/K2S2O8对碱性橙的降解率明显高于纯TiO_2。     

TiO2悬浮体系光催化降解染料动力学研究

在TiO2悬浮体系中,以高压汞灯为光源,研究了活性艳红X-3B光催化脱色反应动力学.考察了X-3B初始质量浓度、pH值、光强、催化剂投加量以及共存无机阴离子和有机物对光解速率的影响.结果表明,该反应可用Langmuir-Hinshelwood(L-H)动力学方程来描述,在较低质量浓度(≤50 mg/L)下光催化降解过程为准一级反应;在本实验条件下,一级反应速率常数k′与初始质量浓度ρ0近似成负一级反应关系,与光强I的根方近似成正比;催化剂的投加量有一适宜值(4 g/L);在偏酸性和碱性条件下光催化降解X-3B脱色较快,且在酸性条件下比在碱性条件下效果更好;除PO43-对反应有促进作用外,大部分无机阴离子(Cl-、SO42-)和有机物(DBS、PVA)对降解均有抑制作用.     

UV/TiO_2光催化氧化处理鲁奇废水生化出水的试验研究

采用UV/TiO_2反应体系对鲁奇废水生化出水进行了光催化氧化试验,考察了pH、TiO_2投加量、反应时间和外加H_2O_2对COD_(Cr)去除率的影响。结果表明:中性及酸性条件下更有利于UV/TiO_2光催化降解鲁奇废水生化出水中的COD_(Cr);在pH值=7和1.0 g/L TiO_2投加量条件下,反应4 h后,COD_(Cr)去除率为61.17%。UV/TiO_2反应体系外加一定量H_2O_2是否会提高其COD_(Cr)去除率与具体的反应体系有关。     

TiO2悬浮体系光催化降解染料动力学研究

在TiO2悬浮体系中，以高压汞灯为光源，研究了活性艳红X－3B光催化脱色反应动力学，考察了X－3B初始质量浓度，pH值，光强，催化剂投加量以及共存无机阴离子和有机物对光解速率的影响，结果表明，庐反应可用Langmuir-Hinshelwood(L-H)动力学方程来描述，在较低质量浓度（≤50mg/L）下光催化降解过程为准一级反应；在本实验条件下，一级反应速率常数k‘与初始质量浓度ρ0近似成负一级反应关系，与光强I的根方近似成正比；催化剂的投加量有一适宜值（4g/L)；在偏酸性和碱性条件下光催化降解X－3B脱色较快，且在酸性条件下比在碱性条件下效果更好，除PO4^3-对反应有促进作用外，大部分无机阴离子（Cl^-,SO4^2-）和有机物（DBS，PVA）对降解均有抑制作用。     

掺铁的锐钛矿相TiO_2在可见光下催化降解酸性红B的研究

对用水热技术制备的掺铁TiO_2粉体进行X射线衍射(XRD)和傅立叶交换红外光谱(FT-IR)表征,以酸性红B模拟废水的降解率,研究自制的掺铁TiO_2粉体的光催化性能。XRD表征显示自制样品为纯锐钛型TiO_2即A-TiO_2;FT-IR结果可知自制样品的晶体结构中存在大量的羟基(OH);光催化结果表明:掺铁能显著提高自制的A-TiO_2光催化效率。当铁的摩尔掺杂量为1.6%时,其光催化活性最好,光照15min与纯TiO_2相比,酸性红B的光催化降解率提高了52.48%;在最佳条件下(酸性红B初始质量浓度为40mg/L、pH为2、摩尔掺铁量为1.6%、催化剂质量浓度为1.5g/L,可见光源40 W白炽灯、光照15min),对酸性红B的降解率达到87.1%。     

Cu掺杂TiO_2光催化剂降解有机染料的研究

采用溶胶-凝胶法制备Cu/TiO_2光催化剂,在汞灯下光催化降解酸性品红溶液。探讨了金属掺杂量,煅烧温度、煅烧时间、催化剂的用量以及溶液初始浓度对光催化降解效率的影响。结果表明,Cu掺杂量为1.5%(摩尔分数)、煅烧温度600℃,煅烧时间2h的制备条件下,催化剂的最佳用量为0.1%(g/mL)对酸性品红染料初始浓度为10mg/L的降解率较高,光照60min后品红降解率可达74.3%;掺杂1.5%(摩尔分数)的Cu/TiO_2催化剂的光催化活性高于TiO_2,其光催化降解率较TiO_2提高了21%。Cu的掺杂可以显著提高TiO_2的光催化效率。     

臭氧/过一硫酸盐在磷酸盐缓冲液中降解阿特拉津实验研究

在磷酸盐缓冲液中考察不同条件下臭氧/过一硫酸盐(O_3/PMS)降解阿特拉津(ATZ)的效果并对其降解机理进行探讨。结果表明,在p H为8的磷酸盐缓冲液中,反应体系温度为20℃,PMS、O_3的浓度分别为10、20μmol/L时,O_3/PMS体系5 min即可将2.5μmol/L的ATZ全部降解完毕。O_3/PMS降解ATZ过程中,磷酸盐是一种优质的缓冲剂,对PMS有激发作用,且表现为酸性条件下激发效果优于碱性条件。无论在酸性还是碱性条件下,O_3/PMS降解ATZ过程中都以自由基氧化降解为主,O_3直接氧化降解比例为6%~7%,酸性条件下以SO_4~(·-)氧化降解占主导地位,中性条件下以HO~·和SO_4~(·-)共同氧化降解且以HO·氧化降解为主,碱性条件下以HO~·和SO_4~(·-)共同氧化降解,且HO·和SO_4~(·-)氧化降解比例接近1:1。     

Cu掺杂TiO_2光催化剂降解有机染料的研究

采用溶胶-凝胶法制备Cu/TiO_2光催化剂,在汞灯下光催化降解酸性品红溶液。探讨了金属掺杂量,煅烧温度、煅烧时间、催化剂的用量以及溶液初始浓度对光催化降解效率的影响。结果表明,Cu掺杂量为1.5%(摩尔分数)、煅烧温度600℃,煅烧时间2h的制备条件下,催化剂的最佳用量为0.1%(g/mL)对酸性品红染料初始浓度为10mg/L的降解率较高,光照60min后品红降解率可达74.3%;掺杂1.5%(摩尔分数)的Cu/TiO_2催化剂的光催化活性高于TiO_2,其光催化降解率较TiO_2提高了21%。Cu的掺杂可以显著提高TiO_2的光催化效率。     

Ti/IrO_2-RuO_2涂层电极对2,4,6-三氯苯酚的氧化降解

采用Ti/IrO_2-RuO_2涂层电极对2,4,6-三氯苯酚(TCP)溶液进行电化学氧化降解研究。结果表明:TCP降解效率与溶液初始p H、溶液初始浓度、电解时间,外加电压、及溶液中电解质的量相关,在外加电压为7 V、p H=3、Na_2SO_410 g/L的条件下,Ti/IrO_2-RuO_2涂层电极对初始浓度为0.025 g/L的TCP溶液处理150 min后,TCP降解效率达到99%以上。通过探讨TCP在酸性条件和碱性条件下降解的中间产物及降解规律,表明在酸性条件下TCP的降解主要是通过·OH自由基氧化和在阳极表面直接氧化的共同作用实现的,而碱性条件下起主要反应的是·OH自由基的氧化作用。     

γ射线辐射作用下硫醚的去除特性研究

随着环保要求的不断提高,对各类燃油中硫化物含量所制定的限制标准将越来越严格。常规的加氢脱硫方法存在工艺复杂、运行成本高等问题,因而探索了利用Y射线辐射去除油品中硫醚硫的新方法。以丁硫醚．十二烷为对象,考察了影响硫醚去除的主要参数。结果表明,丁硫醚的去除率随辐射剂量的增加而上升,去除反应符合一级动力学;在总辐射剂量相同的情况下,使用低剂量率进行辐照可得到较高的去除率,所对应的能量利用率或G因子也较高。另外,氧气对丁硫醚的去除有明显促进作用,当辐照剂量为290kGy时,通入空气时硫醚去除率接近80％,比相同剂量下的静态辐照和通氮气辐照分别提高了近30％及50％。在有氧气的情况下硫醚的辐照产物主要为极性较强的亚砜,很容易从油品中分离。而烷烃在辐射过程中去除量很少,油品的辐射损失不大。此外,还对硫醚的辐射转化机制进行了初步探讨。     

半导体光催化降解十二烷基苯磺酸钠的研究

本文以正业级锐钛矿型TiO2(C-1）、自制纳米锐钛矿型TiO2(C-2）、掺铁TiO2(C-3）及TiO2-SnO2复合催化剂（C-4）对十二烷基苯磺酸钠（DBS）模拟有机废水进行了光催化降解研究，结果表明，改性TiO2催化剂(C-2、C-3、C-4）对DBS的光降解有不同程度的改善，其中以C-2与C-3效果最好。在该实验条件下，反应60min后DBS去除率达90%以上，CODCr去除率也将近70%。此外，以C-1为催化剂，考察了pH值及外加H2O2对DBS光解的影响。     

Facile one-pot preparation of Bi6O6(OH)3(NO3)3•1.5H2O-Bi2WO6 heterostructure with superior photocatalytic activity

Basic bismuth nitrate Bi₆O₆(OH)₃(NO₃)₃•1.5H₂O (BBN) modified Bi₂WO₆ heterostructures was facilely synthesized by one-pot hydrothermal strategy. The modification of BBN effectively improves the photocatalytic activity of Bi₂WO₆ for degradation and mineralization of Rhodamine B. The enhanced photocatalytic performance is attributed to the increased surface area and effective separation of photogenerated carriers induced by the potential difference at BBN/Bi₂WO₆ interface. Furthermore, the micro-scaled heterostructure is easily recycled with excellent circulating stability. The work provides some new insights for the rational design and synthesis of basic salt modified Bi-system photocatalyst with high efficiency.     

以十二烷基苯磺酸钠为模型反应物的Y2O3／TiO2复合催化剂的制备及光降解催化性能

采用浸渍法制备了Y2O3/TiO2复合氧化物催化剂，并用紫外可见光谱、SEM、BET等手段对其进行了表征，以水相十二烷苯苯磺酸钠（DBS）溶液的光催化降解反应为实验模型，考察了TiO2掺杂Y2O3后的光催化氧化活性，并探讨了Y2O3掺杂量、吸附性、焙烧温度及时间对Y2O3/TiO2复合氧化物催化剂光催化活性的影响，实验结果表明：复合氧化物催化剂Y2O3/TiO2存在某一最佳组分比值，当两者重量比为1：200时，其催化活性是同样条件下前体催化剂TiO2的2.4倍。     

聚丙烯透明改性剂的合成及分离纯化研究

利用正交试验法对DBS的合成及纯化条件进行了优化,得出了优惠工艺条件:原料中苯甲醛与山梨醇摩尔比2.2∶1.0,环己烷与甲醇体积比为 70∶30,搅拌速率和反应时间分别是450 rpm和5 h,在此条件下合成DBS,并用环己烷/丙酮混合溶剂提纯,可以得到99%DBS,其收率达到82.9%。     

Effect of synthesis parameters in polyaniline: influence on yield and thermal behavior

Summary Influence of chemical polymerization conditions on the yield and thermal behavior of PANI doped Dodecylbenzensulfonic (DBS) was studied by means of a 2⁴ factorial experimental design. These conditions included temperature, concentration of dopant, concentration of oxidant and stirring rate. It was found that the thermogravimetric behavior was not sensitive to any of the conditions tested. By contrast, the yield was dependent on three of the variables studied. For 10 mmol of aniline, the maximum yield was obtained when temperature, concentration of dopant, concentration of oxidant and stirring rate were 25 °C, 27 mmol, 11.5 mmol and 500 rpm, respectively. The most important effects on the yield are the main effect of oxidant (APS), the interaction dopant concentration-stirring rate and the three-factor interaction effect of dopant concentration-oxidant concentration-stirring rate. The prediction equation is: Mass PANI (g) = 1,5920 + 0,0477 DBS + 0,3496 APS + 0,1080 rpm + 0,0533 DBS*APS + 0,2504 DBS*rpm + 0,0959 APS*rpm + 0,2333 DBS*APS*rpm     

Chemopreventive Efficacy of Atorvastatin against Nitrosamine-Induced Rat Bladder Cancer: Antioxidant, Anti-Proliferative and Anti-Inflammatory Properties

To investigate the anti-carcinogenic effects of Atorvastatin (Atorva) on a rat bladder carcinogenesis model with N-butyl-N-(4-hydroxibutil)nitrosamine (BBN), four male Wistar rat groups were studied: (1) Control: vehicle; (2) Atorva: 3 mg/kg bw/day; (3) Carcinogen: BBN (0.05%); (4) Preventive Atorva: 3 mg/kg bw/day Atorva + BBN. A two phase protocol was used, in which the drug and the carcinogen were given between week 1 and 8 and tumor development or chemoprevention were expressed between week 9 and 20, when the bladders were collected for macroscopic, histological and immunohistochemical (p53, ki67, CD31) evaluation. Serum was assessed for markers of inflammation, proliferation and redox status. The incidence of bladder carcinoma was: control 0/8 (0%); Atorva 0/8 (0%); BBN 13/20 (65%) and Atorva + BBN 1/8 (12.5%). The number and volume of tumors were significantly lower in the Atorva + BBN group, with a marked reduction in hyperplasia, dysplasia and carcinoma in situ lesions. An anti-proliferative, anti-inflammatory and antioxidant profile was also observed in the preventive Atorva group. p53 and ki67 immunostaining were significantly increased in the BBN-treated rats, which was prevented in the Atorva + BBN group. No differences were found for CD31 expression. In conclusion, Atorvastatin had a clear inhibitory effect on bladder cancer development, probably due to its antioxidant, anti-proliferative and anti-inflammatory properties.     

Conducting polymer blends prepared from polyaniline with n-dodecylbenzenesulfonic acid zinc salt as the secondary dopant

A red-shift of the UV–vis spectra of n-dodecylbenzenesulfonic acid doped polyaniline (PANI (DBSA)_0.5), resulting from the secondary doping of polyaniline backbones, was found in the presence of n-dodecylbenzenesulfonic acid zinc salt (Zn(DBS)₂). It is proved to behave as steric hindrance spacers to induce the extension of the conjugation length through the straightening effect on the polyaniline backbones and the obtained mixtures (PANI(DBSA)_0.5 plus Zn(DBS)₂) can be used as master batch materials (MB-13) for blending with regular polypropylene polymer (PP). The thermal degradation accompanied with loss of conductivity for MB-13 can be delayed to over 250°C when enough Zn(DBS)₂ was secondarily doped on PANI(DBSA)_0.5., which allow the performance of its blending with other nonconducting/regular polymers possible. Below 80 rpm, increasing shear rates would induce higher viscosity difference between the MB-13 and PP matrix, resulting in elongation of MB-13 in the PP matrix and higher conductivities of the polyblends. The deviation from the Taylor equation, which is used to estimate the degree of elongation for a polyblend, started when shear rate is over 80 rpm. The leakage of Zn(DBS)₂ out of MB-13 can be confirmed by comparing the DSC thermograms and X-ray diffraction patterns with that of neat PP. Gradual deformation for the conductive fillers (MB-13) and a well-defined and expanded layered structure can be found when processing time is below 15 min with 60 rpm shear rate. The layers started to shrink back after 15 min of procession with the loss of the Zn(DBS)₂ from MB-13 in the PP matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of nucleating agent addition on crystallization of isotactic polypropylene

The isothermal and nonisothermal crystallization kinetics of nonnucleated and nucleated isotactic polypropylene (iPP) were investigated by DSC and a polarized light microscope with a hot stage. Dibenzylidene sorbitol (DBS) was used as a nucleating agent. It was found that the crystallization rate increased with the addition of DBS. The influence of DBS on fold surface energy, σ_e, was examined by the Hoffman and Lauritzen nucleation theory. It showed that σ_e decreased with the addition of DBS, suggesting that DBS is an effective nucleating agent for iPP. Ozawa's theory was used to study the nonisothermal crystallization. It was found that the crystallization temperature for the nucleated iPP was higher than that for nonnucleated iPP. The addition of DBS reduced the Ozawa exponent, suggesting a change in spherulite morphology. The cooling crystallization function has a negative exponent on the crystallization temperature. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2089–2095, 1998