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1.
硅钼黄—乙醇体系光化学还原硅钼蓝分光光度法测定硅   总被引:2,自引:0,他引:2  
含0.8-2.0mol/L HCl的硅钼黄-乙醇溶液体系在波长小于460nm的蓝紫光或紫外照射下,能够发生使硅钼黄定量还原为硅钼蓝的光化学反应。基于这一反应,研究建立了测试样品中硅含量的光化学还原硅钼蓝分光光度法。该法与化学还原硅钼蓝法相比,避免了因加入化学还原剂引起的干扰,重显性好,准确度高,操作简便,快速,测定结果的标准偏差≤0.012%,相对标准偏差≤1%。  相似文献   

2.
磷钨酸均相光催化还原降解水中偶氮染料酸性大红3R   总被引:5,自引:0,他引:5  
以磷钨酸(H3PW12O4记为PW12)作为光催化剂,在异丙醇作为电子给体的条件下对偶氮染料酸性大红3R(记为AR3R)进行光催化均相还原脱色研究。循环伏安法、暗反应、O2竞争抑制等实验表明杂多蓝(PW12O404-)对AR3R 具有明显的还原脱色作用。实验研究了催化剂PW12用量、异丙醇浓度、染料浓度、盐浓度对PW12/异丙醇光催化还原降解酸性大红3R的影响。结果表明:AR3R的光催化脱色速率随催化剂PW12、异丙醇浓度的增加而增加,最后趋于恒定;随染料初始浓度增加,初始光解速率增大,且符合Langmuir-Hinshelwood动力学方程;随盐浓度增加,染料脱色速率减小,表现为负的盐效应。由此推测AR3R与光反应生成的杂多蓝预先进行复合,然后发生电子转移引起偶氮染料还原脱色,杂多蓝氧化复原。本研究结果表明磷钨酸/异丙醇/UV绿色光催化还原体系能够有效用于偶氮染料废水的还原脱色处理。  相似文献   

3.
Rao等曾采用硫酸肼还原、钒酸盐滴定的方法测定纯溶液中的钼。但该文末提及杂质的干扰问题。所拟条件也常使钼的还原率偏低。本工作在以硫酸肼还原高价钼时,添加8-羟基喹啉,以使还原反应达到完全;添加草酸以防止形成钼蓝,并改进了有关滴定条件,从而改善了方法的准确度。本法快速,简便,特效性高,适于含钼在5%以上的钼矿及钼铁的分析。准确度不低于钼酸铅重量法。 (一)主要试剂钼标准溶液:称光谱纯MoO_36.0014克,以1%NaOH溶液溶解,并准确稀释至  相似文献   

4.
赖宇坤  王炜 《电化学》2011,17(1):102-106
研究了以循环伏安法测定铁胺络合物还原强度的准确度及其影响因素,优化阴极电解液(包括硝酸铁、三乙醇胺、氢氧化钠、硝酸钙).实验表明,由循环伏安法测定的铁胺络合物还原强度与浸染染色法测得的比较,前者准确度好、稳定性高,而且操作方便快捷,在电化学还原染色生产和质量控制中具有重要的应用价值.  相似文献   

5.
通过水热法和光还原方法成功地制备了铌酸锰-还原氧化石墨烯复合光催化剂。这种复合光催化剂可以明显地提高光催化降解亚甲基蓝的光催化活性,降解效率在60 min内达到了78.2%,是单体铌酸锰降解效率的2倍。通过活性物质捕获实验的研究,增强的光催化性能可以归因于还原氧化石墨烯加速了光生电子-空穴的分离效率,进而解决了低光催化活性的问题。  相似文献   

6.
通过水热法和光还原方法成功地制备了铌酸锰-还原氧化石墨烯复合光催化剂。这种复合光催化剂可以明显地提高光催化降解亚甲基蓝的光催化活性,降解效率在60 min内达到了78.2%,是单体铌酸锰降解效率的2倍。通过活性物质捕获实验的研究,增强的光催化性能可以归因于还原氧化石墨烯加速了光生电子-空穴的分离效率,进而解决了低光催化活性的问题。  相似文献   

7.
菲的电解还原胡明,刘旭光,王志忠(太原工业大学,太原030024)关键词菲,有机电化学,电解还原近年来有机电解技术引入煤转化领域的研究已有过一些综述 ̄[1~6]。以多环芳烃为模型化合物,研究其在电解条件下的转化行为,从理论和实践上都将为煤及其加工产品...  相似文献   

8.
光谱电化学法研究亚甲基蓝的电还原反应   总被引:6,自引:0,他引:6  
用极谱法研究亚甲基蓝(MB)的电极吸附过程早有报道.近几年,用光谱电化学法研究其电化学行为又引起了许多人的兴趣.但在光透薄层电极上,由于光程太短,测试溶液浓度较高,导致亚甲基蓝发生聚合,影响实验结果的准确测定.为此本文利用特制的比色皿型长光程薄层光谱电化学池,在低浓度条件下研究其在SnO_2镀膜玻璃电极上的电还原反应.  相似文献   

9.
利用极谱,Ⅲ利用电位阶跃研究了轻稀土离子在碱金属氯化物熔盐中的阴极还原。本文作者研究过Sm~(3 )在NaCl-KCl熔盐中的电还原。上述工作分别提出了稀土离子一步还原和分步还原的结论。本文采用线性扫描伏安法和恒电位电解,并配以扫描电子显微镜X射线能谱分析,对Nd~(3 )在Pt电极上的阴极还原过程进行了研究,利  相似文献   

10.
面包酵母用于苯乙酮的不对称还原研究   总被引:17,自引:1,他引:17  
刘湘  孙培冬  李明  许建和 《分子催化》2002,16(2):107-110
研究了面包酵母用于苯乙酮的不对称还原,分别考虑了反应温度,反应时间,底物浓度等因素对转化率和对映选择性的影响,结果表明,在合适的生物转化条件下,底物苯乙酮以中等的转化率被还原并得到较高对映体过量值的产物S-1-苯基乙醇。  相似文献   

11.
Zusammenfassung Folgende organische Farbstoffe, die entweder als Pulver oder auch als Ausfärbung oder als Druck vorlagen, gaben kennzeichnende Sublimate:Indischgelb G, Dianilgelb G, die Hansagelbsorten 10 G, 5 G, 5 G transparent, 3 G, G, G transparent, GGR extra, GR, 3 R, Litholechtgelb RN, Helioechtgelb 6 GL, Litholechtorange RN, Permanentrot R extra, Litholechtscharlach RN (Hansarot B), Litholechtscharlach B, Permanentrot FRL, Autolrot BL, Autolrot RLP, Brillant-Indigo BASF, Indanthrengelb G, Indanthrenbraun G, Indanthrenblau RSN, Indanthrenviolett FFBN, Indanthrengelb 7 GK, Indanthrenbrillantorange GR, Indanthrenbrillantorange RK.
Summary The following organic dyestuffs which were present either as powders or as dyed or printed material, gave characteristic sublimates:Indian yellow G, dianil yellow G, the 10 G, 5 G, 5 G transparent, 3 G, G, G transparent, GGR extra, GR, 3 R brands of Hansa yellow, lithol-fast yellow RN, helio-fast yellow 6 GL, lithol-fast orange RN, permanent red R extra, lithol-fast scarlet RN (Hansa red B), lithol-fast scarlet B, permanent red FRL, autol red BL, autol red RLP, brilliant indigo BASF, indanthrene yellow G, indanthrene brown G, indanthren blue RSN, indanthrene violet FFBN, indanthrene yellow 7 GK, indanthrene brilliant orange GR, indanthrene brilliant orange RK.

Résumé Les pigments organiques suivants, qui étaient à notre disposition, soit comme poudre, soit comme colorisation ou comme impression, donnèrent des sublimés caractéristiques:Indischgelb G, Dianilgelb G, les sortes de Hansagelb 10 G, 5 G, 5 G transparent, 3 G, G, G transparent, GGR extra, GR, 3 R, Litholechtgelb RN, Helioechtgelb 6 GL, Litholechtorange RN, Permanentrot R extra, Litholechtscharlach RN (Hansarot B). Litholechtscharlach B, Permanentrot FRL, Autolrot BL, Autolrot RLP, Brillant-Indigo BASF, Indanthrengelb G, Indanthrenbraun G, Indanthrenblau RSN, Indanthrenviolett FFBN, Indanthrengelb 7 GK, Indanthrenbrillantorange GR, Indanthrenbrillantorange RK.
  相似文献   

12.
For the present study, the cotton fabric and dye solution were irradiated to UV radiation for different times. Dyeing was performed using un-irradiated and irradiated cotton with un-irradiated and irradiated reactive blue dye. Different dyeing parameters such as temperature, pH and time were optimized using irradiated dye and irradiated cotton. The data of colour report were obtained from un-irradiated and irradiated cotton dyed with reactive blue dye using spectra flash (SF650). Colourfastness properties show that UV radiation of both cotton and dye powder has improved the grading of fastness from fair to good. It is found that UV irradiation has not only enhanced the strength of dye on irradiated fabric but also improved the dyeing properties.  相似文献   

13.
采用显微镜研究了预交联聚合物凝胶溶液的染色过程,结果表明由于静电作用,亚甲基蓝溶液中阳离子基团与凝胶颗粒中的阴离子基团相互作用形成一种深蓝色的缔合物;交联聚物线团也可以与亚甲基蓝分子形成深蓝色的缔合物,使交联聚合物线团显色,能够直接观测到交联聚合物线团在溶液中的形态。采用扫描电镜、动态光散射、流变仪和岩心封堵实验研究了染色后交联聚合物的线团形态尺寸和溶液的流变性、封堵特性。结果表明,染色后的交联聚合物线团仍是几百纳米左右的在水中分散的球形体,在形态和尺寸上与未染色的交联聚合物溶液没有发生较大的变化;染色后交联聚合物溶液在一定剪切速率范围内表现为胀流性和负触变性。  相似文献   

14.
Reactive dyeings were carried out by exhaust method on 100% cotton knits. A trichromatic combination was chosen with only change in blue component. Colorimetric data were produced under controlled dyeing conditions by comparing the color difference between the target shade and resulting shades. Giving a change in liquor ratio and nature of salt the colorimetric data were regenerated again produced the shades. The data will be helpful to predict the low-sensitivity reactive dye recipe, which lead to the concept of right-first-time dyeing. The aim of this research is to help a dyer to select the right recipe. A set of the dye recipes was applied by dyeing with reactive dyes on cotton. Sodium chloride shows best results in terms of dye sensitivity as compared to Glauber's salt at low liquor ratio that is 1:10. Blue BRF in combination with yellow and red shows best result as compared to navy blue BF.  相似文献   

15.
建立了快磺素的可见-紫外定量测定方法。蓝色盐VB转变成快磺素再测定。在波长265nm或427nm处,样品浓度5~40mg·L-1时,浓度与吸光度呈线性,可用于工业分析。  相似文献   

16.
S-Transfer Reactions with Bis(imidazolo)sulfane and Silylated Sulfur-Nitrogen Compounds: Synthesis of Functionally Thiosulfurdiimides Sulfinimideamides Rs(NSiMe3)N(SiMe3)2 ( 1 ) (R = t-Bu or Ph) react with bis(imidazolo)sulfane via SIVII-? redox transimination”? yielding thiosulfurdiimides RSN ? S ? NSiMe3 ( 2 ), which reacts with further bis(imidazolo)sulfane to give dithiosulfur-dimides RSN ? NSR ( 3 ). Solvolysis of 2 with MeOH gives the corresponding NH-compounds RSN ? S ? NH ( 4 ).  相似文献   

17.
Physical adsorption is a common method to solve the contamination of methylene blue in dyeing wastewater. As a kind of adsorption material, cellulose aerogels with high porosity and surface areas have great potential application in methylene blue removal. However, the week hydrogen bonding between cellulose nanofibers making the cellulose aerogels with the poor mechanical properties and can be easily destroyed during adsorption. Hence, the preparation of cellulose aerogels with high mechanical strength is still a great challenge. Here, we report a robust super-assembly strategy to fabricate cellulose aerogels by combining cellulose nanofibers with PVA and M-K10. The resulting cellulose aerogels not only has a robust chemically cross-linked network, but also has strong H-bonds, which greatly enhance the mechanical properties. The resulting cellulose aerogels possess a low density of 19.32 mg/cm3.Furthermore, the cellulose aerogel shows 93% shape recovery under 60% strain(9.5 k Pa under 60% strain)after 100 cycles, showing excellent mechanical property. The adsorption capacity of cellulose aerogel to methylene blue solution of 20 mg/L is 2.28 mg/g and the adsorption kinetics and adsorption isotherms have also been studied. Pseudo-second-order kinetic model and Freundlich isotherm model are more acceptable for indicating the adsorption process of methylene blue on the cellulose aerogel. Thus, this compressible and durable cellulose aerogel is a very prospective material for dyeing wastewater cleanup.  相似文献   

18.
Using 1-alkenes as solvent, catalytic reduction of alkynes in the presence of Lindlar's catalyst is achieved without risking over-reduction of terminal unsaturation.  相似文献   

19.
Novel acid mono azo and mordent acid mono azo dyes were synthesized by the coupling of diazonium salt solution of different aromatic amines with 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid. The resulting dyes were characterized by spectral techniques like elemental analysis, IR, 1H-NMR and UV visible spectroscopy. The dyeing performance of all the dyes was evaluated on wool and silk fabrics. The dyeing of chrome pre-treated wool and silk fabrics showed better hues on mordented fabrics. Dyeing of wool and silk fabrics resulted in pinkish blue to red shades with very good depth and levelness. The dyed fabrics showed excellent to very good light, washing, perspiration, sublimation and rubbing fastness.  相似文献   

20.
多组份聚丙烯共混物的微观结构及共混纤维的染色性能   总被引:3,自引:0,他引:3  
研究了PP GPET、PP GPET EVA、PP GPET EVA PS共混物的结构和性能 .研究表明 ,PP GPET体系属于非相容共混体系 ,共混物呈典型海岛型两相结构 ,EVA的加入可以改善体系相容性 ;共混物的结晶度比纯聚丙烯低 ,PS有增大共混物晶粒尺寸的作用 ;改性聚丙烯纤维的染色性有明显提高 ,用分散染料E EX可染成深蓝色  相似文献   

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