Photoinduced electron transfer from electron donor to bis-carbocyanine dye in excited triplet state

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Localized hydrogels based on cellulose nanofibers and wood pulp for rapid removal of methylene blue

Access to clean water has become increasingly difficult, motivating the need for materials that can efficiently remove pollutants. Hydrogels have been explored for remediation, but they often require long times to reach high levels of adsorption. To overcome this limitation, we developed a rapid, locally formed hydrogel that adsorbs dye during gelation. These hydrogels are derived from cellulose—a renewable, nontoxic, and biodegradable resource. More specifically, we found that sulfated cellulose nanofibers or sulfated wood pulps, when mixed with a water-soluble, cationic cellulose derivative, efficiently remove methylene blue (a cationic dye) within seconds. The maximum adsorption capacity was found to be 340 ± 40 mg methylene blue/g cellulose. As such, these localized hydrogels (and structural analogues) may be useful for remediating other pollutants.     

Conjugated polymer with rigid donor poly(para‐divinylphenylamino) backbone and pendant cyanoacetic acid acceptor for dye sensitized solar cells

A donor backbone [poly(para‐divinylphenylamino)]‐acceptor (cyanoacetic acid side group) type conjugated polymer ( P2 ) has been synthesized and used as the active material for dye‐sensitized solar cells. DFT calculation shows that the insertion of vinyl link in the polymer backbone leads to a planar structure in P2 and changes the excited state significantly. Photoelectrochemical cells based on the DSSC format were fabricated using the polymers as sensitizers. The cell constructed using P2 exhibits a considerably high peak IPCE and J‐V response, with an overall power conversion efficiency of 3.67%. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2958–2965     

Use of metal composite MOF‐5‐Ag2O‐NPs as an adsorbent for the removal of Auramine O dye under ultrasound energy conditions

In this work, MOF‐5 composited with Ag₂O nanoparticles was prepared and characterized via X‐ray diffraction, field emission‐scanning electron microscopy, energy‐dispersive spectroscopy and FT‐IR analysis. This new material was subsequently employed for removing basic yellow dye [Auramine O (AO)] from aqueous solution under ultrasound irradiation. Several experiments were designed by central composite design in which operational parameters such as such as pH, MOF‐5‐Ag₂O mass and initial concentration of AO involved in the process were optimized. The significance of individual parameters and their possible interactions were investigated using analysis of variance (anova ). The optimum values of 6, 0.025 g and 6 mg l^?1 were obtained for the pH, MOF‐5‐Ag₂O‐NPs mass and the initial concentrations of AO, respectively, with desirability of 1.0. At such conditions, the efficiency for the removal of AO was found to be 89.45%. Various isotherm models for fitting the experimental equilibrium data were studied, and it was found that the Langmuir model has the highest efficiency for correlation of experimental equilibrium data, so that the monolayer adsorption capacity of MOF‐5‐Ag₂O for successful removal of AO was 260.70 mg g^?1 at optimal conditions.     

A Carboxyl-Functionalized Covalent Organic Framework Synthesized in a Deep Eutectic Solvent for Dye Adsorption

Instead of using organic solvents, a deep eutectic solvent (DES) composed of tetrabutylammonium bromide and imidazole (Bu₄NBr/Im) was employed as a solvent for the first time to synthesize covalent organic frameworks (COFs). Due to the low vapor pressure of the Bu₄NBr/Im-based DES, a new carboxyl-functionalized COF (TpPa-COOH) was synthesized under environmental pressure. The as-synthesized TpPa-COOH has open channels, and the DES can be removed completely from the pores. The dye adsorption performance of TpPa-COOH was examined for three organic dyes with similar molecular sizes: one anionic dye (eosin B, EB) and two cationic dyes (methylene blue, MB and safranine T, ST). TpPa-COOH showed an excellent selective adsorption effect on MB and ST. The electronegative keto form in TpPa-COOH might help to form electrostatic and π–π interactions between the π-stacking frameworks of TpPa-COOH and the positive plane MB and ST molecules. The adsorption isotherms of MB and ST on TpPa-COOH were further investigated in detail, and the equilibrium adsorption was well modeled by using a Langmuir isotherm model. Together with hydrogen bonding, TpPa-COOH showed higher adsorption capacity for ST than for MB (1135 vs. 410 mg g⁻¹). These results could provide a guidance for the green synthesis of adsorbents in removing organic dyes from wastewater.     

气相色谱-质谱法同时测定氧化型染发剂中的17种染料

建立了氧化型染发剂中17种染料中间体(包括苯二胺类、氨基酚类、苯二酚类、萘酚和氨基吡啶类等)的气相色谱-质谱检测方法. 采用体积分数为50%的乙醇超声提取染发剂中的染料中间体, 加入还原剂连二亚硫酸钠防止待测物变质, 选择DB\|WAX毛细管柱实现了在25 min内同时分离17种水溶性和醇溶性染料. 结果表明, 本方法对所测物质的检出限(LOD)为2～380 mg/kg, 定量限(LOQ)为7.5～1267.5 mg/kg. 在1, 2, 10, 20或100倍LOQ 4个添加水平下的平均回收率在81.1％～103.7％之间, 相对标准偏差(n=6)在0.67%～3.73%之间.     

基于LR305的平面荧光太阳能聚光波导研制

光伏发电是目前太阳能最佳的利用方式之一,但发电成本高。利用聚光结构提高光的转换和收集效率,是提高太阳能电池效率、减少电池用量、降低光伏发电系统成本的重要途径。以Lumogen F Red 305 (LR305) 染料作为荧光材料,将其掺杂到PMMA中,通过本体聚合法制作出尺寸为50 mm×50 mm×5 mm的PMMA平面荧光太阳能聚光波导,对其光学特性进行表征,同时将太阳能电池粘贴到聚光波导的输出端面,通过测试平面荧光太阳聚光波导对太阳能电池性能的影响研究了荧光太阳能聚光波导的聚光特性。     

半菁染料作为染料敏化太阳能电池吸光材料的理论研究

采用第一性原理研究了半菁-二氧化钛团簇形成的配合物(hemicyanine-(TiO₂)_n)的光电子转移过程, 这里n分别取5, 9, 15. 配合物基态构型采用密度泛函理论方法进行优化, 而激发态采用含时密度泛函理论进行计算. 采用长程相关校正的密度泛函CAM-B3LYP和ωB97X-D计算的激发能与实验值吻合得很好. 依据广义Mulliken-Hush (GMH)公式, 基于密度泛函理论得到的波函数被用来计算电荷转移积分, 进而可根据Marcus理论计算出电荷分离速率常数(k_CS)和电荷回传速率常数(k_CR). 计算结果表明电子从染料到(TiO₂)_n团簇的传递有多条通道, 这使得k_CS具有更大值, 相反, 只具有单通道的电荷回传降低了k_CR值, 与k_CS相比甚至可以忽略, 这表明在所研究的体系中电荷回传是不利的.     

发光光弹性涂层荧光信号强度的影响因素

为提高发光光弹性涂层方法中涂层的荧光信号强度,以液态E-44型环氧树脂为光弹性材料、罗丹明B为荧光染料,制作了新、旧两种不同结构的发光光弹性涂层.通过对新、旧两种结构发光光弹性涂层受465nm光波激发时荧光发射光谱的比较,说明新的发光光弹性涂层结构比原有发光光弹性涂层在提高测量信号强度方面的优势,测量结果还表明:发光光弹性涂层测量信号的强度提高还与合理选择涂层中荧光染料浓度、荧光信号发射波长有直接关系.