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31.
研究对羟基偶氮苯甲酸(PHABA)的合成方法及其光响应性能。在低温盐酸条件下,完成对氨基苯甲酸与亚硝酸钠的重氮化反应,再与苯酚pH=9条件下完成偶合反应,产品收率82.6%。氯仿溶剂中,PHABA特征吸收波长为357 nm和240 nm,紫外光照射实验显示,PHABA具备动力学一级反应特征的顺反异构光致变色特性,速率常数为7.46×10-4 min-1。  相似文献   
32.
Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye reduction mechanisms was determined by investigating the reduction of Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under different conditions. Reduction rates of two azo dyes were compared in batch assays over a range of sulphide concentrations in the presence of living or inactivated anaerobic granular sludge. Biological dye reduction followed zero order kinetics and chemical dye reduction followed second-order rate kinetics as a function of sulfide and dye concentration. Chemical reduction of the dyes was greatly stimulated in the presence of autoclaved sludge: whereas chemical dye reduction was not affected by living or gamma-irradiated-sludge. Presumably redox-mediating enzyme cofactors released by cell lysis contributed to the stimulatory effect. This hypothesis was confirmed in assays evaluating the chemical reduction of AO7 utilizing riboflavin, representative of the heat stable redox-mediating moieties of common occurring flavin enzyme cofactors. Sulfate influenced dye reduction in accordance to biogenic sulfide formation from sulfate reduction. In assays lacking sulfur compounds, dye reduction only readily occurred in the presence of living granular sludge, demonstrating the importance of enzymatic mechanisms. Both chemical and biological mechanisms of dye reduction were greatly stimulated by the addition of the redox-mediating compound, anthraquinone-disulfonate. Based on an analysis of the kinetics and demonstration in lab-scale upward-flow anaerobic sludge bed reactors, the relative importance of chemical dye reduction mechanisms in high rate anaerobic bioreactors was shown to be small due to the high biomass levels in the reactors.  相似文献   
33.
Photo-induced molecular alignment behavior of azo dye derivative (sodium 4,4′-bis (4-hydroxy-3-carboxy-phenylazo) benzidine-2,2′-disulphonate: SD1) was investigated using SD1 film prepared by spin-coating method. As-prepared SD1 film was composed of an amorphous layer with smooth surface. Upon linearly polarized UV light irradiation, the film surface was roughened slightly and X-ray diffraction measurement and transmittance electron microscope observation indicated that SD1 molecules crystallized with orientation. Molecular plane of SD1 aligned parallel to the substrate surface along the normal to the polarization direction of irradiated UV light through the trans-cis and cis-trans isomerizations of the azobenzene chromophore.  相似文献   
34.
提高涂料染色摩擦牢度的新途径   总被引:2,自引:2,他引:2  
王庆淼  赵振河 《印染》1998,24(3):8-12
为克服常规涂料染色摩擦牢度低的弊病,作者提出采用以超微偶氮颜料为核,以丙烯酸酯类粘合剂为壳的新型颜料包覆体染色新的探索途径。文中阐述了颜料包覆体合成的意义,合成了大红超微颜料分散体和颜料包覆体YB-R,并对其进行染色性能和透射电镜的测试,表明大大提高了织物的摩擦牢度。本方法进一步完善可扩大涂料染色的应用范围,具有很大的理论研究和实际应用价值。  相似文献   
35.
We have developed a stroboscopic near-field optical microscope for observation of biological specimens and observed glycerinated muscles before and after muscle contraction with the developed system. In the system, the optical field distribution localized near the specimen is recorded as the surface topographic distribution of a photosensitive film surface. Our system is very useful for observing living biological specimens with high resolutions, because it is possible to get stroboscopic image by using a photosensitive film as detecting optical distributions instead of a scanning of probes. We have succeeded in observing inner structures of muscle cells with sub-wavelength resolution and achieved higher contrast than an ordinary optical microscope.  相似文献   
36.
In this paper, photoresponsive behavior of multi-bilayered films having precisely controlled layer thickness prepared by stacking an azo-functionalized polymer liquid crystal, PMAzXAc, and polyvinyl alcohol alternatively, PVA, is described. The multi-bilayered films were found to reflect a light of specific wavelength depending on the layer thickness and refractive index, and showed the reversible change in the reflection intensity by irradiation with visible and UV lights. The change in the reflection intensity was brought about by change in the molecular orientation of PMAzXAc between an out-of-plane orientation and a photo-induced isotropic state, and was strongly dependent on the number of methylene spacer of PMAzXAc linking the azobenzene side group with the acrylate polymer main chain. PMAz6Ac with hexa-methylene spacer showed the largest change in the reflection intensity, while smaller change in the reflection intensity was observed for PMAzXAc having shorter or longer methylene spacer than 6. The effect of the methylene spacers on the photochemical change in the molecular orientation of azobenzene chromophores in the multi-bilayered films will be discussed.  相似文献   
37.
In the present work removal of an azo dye (Reactive Black 5) was investigated from aqueous solution by adsorption onto scallop as a low-cost and widely available adsorbent. The effect of various operational parameters, such as contact time, pH, initial dye concentration and adsorbent dosage on the removal efficiency of dye was studied. Removal efficiency declined with the increase in solution pH and initial dye concentration but with the decrease in adsorbent dosage. Experimental equilibrium and kinetics data were fitted by Langmuir and Freundlich isotherms and pseudo-first-order and pseudo-second-order kinetic models, respectively.  相似文献   
38.
Electrochemical advanced oxidation processes (EAOPs) are used to chemically burn non biodegradable complex organic compounds that are present in polluted effluents. A common approach involves the use of TiO2 semiconductor substrates as either photocatalytic or photoelectrocatalytic materials in reactors that produce a powerful oxidant (hydroxyl radical) that reacts with pollutant species. In this context, the purpose of this work is to develop a new TiO2 based photoanode using an optic fiber support. The novel arrangement of a TiO2 layer positioned on top of a surface modified optical fiber substrate, allowed the construction of a photoelectrochemical reactor that works on the basis of an internally illuminated approach. In this way, a semi-conductive optical fiber modified surface was prepared using 30 μm thickness SnO2:Sb films on which the photoactive TiO2 layer was electrophoretically deposited. UV light transmission experiments were conducted to evaluate the transmittance along the optical fiber covered with SnO2:Sb and TiO2 showing that 43% of UV light reached the optical fiber tip. With different illumination configurations (external or internal), it was possible to get an increase in the amount of photo-generated H2O2 close to 50% as compared to different types of TiO2 films. Finally, the electro-Fenton photoelectrocatalytic Oxidation process studied in this work was able to achieve total color removal of Azo orange II dye (15 mg L−1) and a 57% removal of total organic carbon (TOC) within 60 min of degradation time.  相似文献   
39.
Decolouration of industrial azo dyes by crude laccase from Trametes hirsuta   总被引:1,自引:0,他引:1  
The decolouration of several azo dyes, commonly used in the leather industry, by crude laccase obtained from Trametes hirsuta cultivation was assessed. Among the six dyes studied four showed a decolouration percentage higher than 50% in 4h, whereas the other two showed more resistance to degradation. These results show the ability of laccase towards different dye structures as well as its enormous potential for the decolouration of recalcitrant azo dyes.  相似文献   
40.
In the present study, an Enterococcus gallinarum strain was isolated from effluent treatment plant of a textile industry based on its ability to decolourize C.I. Direct Black 38 (DB38), a benzidine-based azo dye. Effects of dye concentration and medium composition on dye decolourization were studied. The strain was found to decolourize DB38 even under aerobic conditions. Kinetics of DB38 decolourization was also examined, and V(max) and K(s) of decolourization were found to be higher in Luria broth (12.8 mg l(-1)h(-1) and 490.6 mg l(-1)) than in minimal medium (4.09 mg l(-1)h(-1) and 161.84 mg l(-1)). However, decolourization rate/biomass was found to be higher in minimal medium than in Luria broth, indicating greater decolourization efficiency of biomass in the former. The study also revealed biodegradation of DB38 to benzidine and its further deamination to 4-aminobiphenyl (4-ABP) by the culture. Ammonia released during this process was used as nitrogen source for growth of the culture.  相似文献   
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