Facile Fabrication of Large Area Polystyrene Colloidal Crystal Monolayer via Surfactant-free Langmuir-Blodgett Technique

A facile and novel method for the production of a large area of well-ordered polystyrene(PS)colloidal crystal monolayer was established using the surfactant-free Langmuir-Blodgett(LB)technique.The hydrophobic property(film-forming ability)of PS spheres was improved by a thermo-rheology treatment before LB assembly,and a large film was obtained.In contrast to the traditional LB technique,no surfactant was needed in this method,which could eliminate the additional contamination of surfactants in the preparation process and provided the products with versatile applications in nanosphere lithography(NSL)for biosensor,surface plasmon resonance,and surface enhanced Raman spectroscopy.     

INVERSE OPALINE STRUCTURE TITANIA PHOTONIC CRYSTALS BY FUNCTIONALLY MODIFIED COLLOIDAL CRYSTALS TEMPLATING

Ordered macroporous titania photonic crystals （PCs） and photonic balls were fabricated by functional modified polymer colloidal crystals. The TiO2 PCs and balls formed through this method exhibit no cracks and lacunae in large areas on their surface and their inner structures.     

水热法合成多金属氧酸盐棒状超细晶体

以SrCl₂·6H₂O、(NH₄)₆P₂Mo₁₈O₆₂·nH₂O为原料，在PEG-600/H₂O微乳体系中于80～130 ℃温度下水热反应8～12 h，从而制得一种多金属氧酸盐棒状超细晶体，组成是Sr₃P₂Mo₁₈O₆₂·nH₂O。该超细晶体具有长棒状形貌、高结晶度且分散性能较好，长度范围在10.0～20.0 μm，径度在1.0～2.0 μm。对反应体系中的PEG-600/H₂O体积比(V_PEC-600∶V_H2O)、水热温度以及(NH₄)₆P₂Mo₁₈O₆₂·nH₂O/SrCl₂·6H₂O质量比(W_POMs∶W_SrCl2·6H2O)3个影响因素进行了探讨，结果表明：V_PEC-600∶V_H2O主要对棒状超细晶体的形貌、长径比以及晶体结晶度有着重要影响，体积比在范围V_PEC-600∶V_H2O=(1.50～2.00)∶1.00有利于大长径比的棒状超细晶体的形成；水热温度则优选80～130 ℃范围，过低则不发生反应，过高则发生了多金属氧酸盐与PEG-600的氧化-还原反应；W_POMs∶W_SrCl2·6H2O基本上不影响超细晶体的形成。还初步探讨了该棒状超细晶体的形成机理。     

镀金和碳纳米管修饰金电极上吸附态葡萄糖氧化酶比活性的EQCM研究

采用石英晶体微天平(EQCM)技术监测了裸金电极、镀金和碳纳米管修饰金电极上葡萄糖氧化酶(GOD)的吸附过程. 通过EQCM测量吸附固定的GOD质量, 并实时检测酶反应产物H2O2的氧化电量, 求算了各表面上吸附态GOD的比活性(ESAi). 结果表明, 各表面上均可吸附一定的GOD, 且吸附态GOD均有一定的酶活性; 修饰CNTs可增大酶吸附量和酶电极对葡萄糖的响应电流, 但ESAi随CNTs修饰量的增大而降低; Au电极上电镀金后, 酶吸附量和酶电极对葡萄糖的响应电流亦增大, 但ESAi与裸金电极上的基本一致.     

Growth and Spectral Properties of Yb^3＋-doped Ba3Gd（BO3）3 Crystal

Crystal of Yb3+-doped Ba3Gd(BO3)3 has been grown by the Czochralski method. The spectroscopic characterizations have been investigated at room temperature. The Yb3+:Ba3Gd(BO3)3 crystal exhibits broad absorption at 976nm with FWHM of 7nm and large overall spitting of 2F7/2 manifold (823cm-1). The absorption and emission cross sections are 5.09×10-21cm2 at 976nm and 0.97×10-21cm2 at 1040nm,respectively. The fluorescence lifetime is 2.84 ms.     

Growth, Band Structure and Optical Properties of LiSrBO3 Crystal

The bulk crystal of LiSrBO3 (8.39 g) with a size of 21mm×20mm×15mm was grown by high temperature solution growth method. The relationship between growth habit and crystal structure was discussed. The transmission spectrum shows an UV absorption edge at about 300 nm. The melting temperature of this crystal was determined to be 942 ℃ by DTA-TG measurement. The band structure of the LiSrBO3 crystal was studied by means of the first principle method. An indirect band gap was found to be about 4.0 eV,and a low dielectric constant was estimated to be about 1.9 in terms of theoretical results.     

2,4,6-三氯酚分子印迹光子晶体水凝胶传感器的研究

以SiO2三维光子晶体为模板,2,4,6-三氯酚为印迹分子,甲醇为溶剂,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸甲酯为交联剂,通过紫外光引发聚合,在2%氢氟酸溶液中去除光子晶体模板,0.015 mol/L NaOH溶液中洗脱印迹分子,制得2,4,6-三氯酚检测用分子印迹光子晶体水凝胶传感器。结果表明,传感器对2,4,6-三氯酚具有良好的响应与识别能力,在2,4,6-三氯酚浓度由0增加到6×10-4 mol/L过程中,吸收峰红移31 nm;浓度继续增加,吸收峰开始发生蓝移;当浓度增加到1×10-3 mol/L时,吸收峰蓝移56 nm,响应时间仅需要30 min。2,4,6-三氯酚分子印迹光子晶体水凝胶传感器具有高灵敏、高选择、易操作等优点,可实现对2,4,6-三氯酚的裸眼检测。     

多重网络增强的层状光子晶体水凝胶及应力变色响应

基于PDGI/PAAm (PDGI/SN)层状光子晶体水凝胶,制备了多重网络PDGI/PAAm-PAMPS-PAAm(PDGI/TN)水凝胶,将水凝胶浸入6 : 4(V/V)乙醇水溶液中去溶胀,记为凝胶PDGI/TN-0.6。结果表明,引入多重网络之后,PDGI/TN凝胶的溶胀率从PDGI/SN的850% ± 45%提高到1070% ± 50%,颜色从蓝色(λ_max=450 nm)变为透明,去溶胀后Bragg衍射峰为670 nm,实现凝胶的Bragg衍射峰在450－670 nm间调控。拉伸和压缩实验说明,PDGI/TN-0.6力学性能优异,拉伸强度和压缩强度分别达到0.99和37.0 MPa。同时,PDGI/TN-0.6具有优异应力变色响应性,压缩应变(ε_c)从0增加到0.5,Bragg衍射峰发生蓝移,响应范围覆盖可见光;当撤去应力后,立即恢复初始状态,可重复多次。利用扫描电镜(SEM)进一步研究了层状光子晶体水凝胶层微观结构。     

ZnSe:Mn/ZnSe纳米晶体中的Mn~(2+)离子扩散

以ZnSe:Mn/ZnSe纳米晶体为基础,分析了Mn~(2+)离子在纳米晶体中的扩散行为.通过电子顺磁共振(EPR)谱参数确定Mn~(2+)离子处在纳米晶体内部.考虑到合成过程,确定Mn~(2+)离子处于纳米晶体的核壳界面.通过荧光光谱来揭示不同退火温度和退火时间下的纳米晶体的光学性质.不同退火条件情况下纳米晶体中各元素的含量由电感耦合等离子体(ICP)发射光谱得到.随着退火温度的增加和退火时间的延长,相同物质的量的纳米晶体中Mn元素含量逐渐变小直到为零,Zn和Se的含量几乎不变.相同退火温度不同退火时间下的电子透射显微镜照片说明退火对纳米晶体的形貌和粒径几乎没有影响.