新型六芳基双咪唑光引发剂的合成和应用

合成了2,2’-二(2-溴-5-甲氧基苯基)-4,4’-5,5’-四苯基-二咪唑(M-HABI)光引发剂。与邻氯代六芳基双咪唑(BCIM)相比,其紫外吸收光谱发生红移,365nm摩尔消光系数比BCIM高1.8倍,光引发效率也比BCIM高,用它制作的感光干膜的感光灵敏度比BCIM低30%。     

Antimicrobial and Antioxidative Activity of Newly Synthesized Peptides Absorbed into Bacterial Cellulose Carrier against Acne vulgaris

The ongoing search for effective treatment of Acne vulgaris is concentrated, i.a., on natural peptides with antimicrobial properties. The aim of this work was the development of new amino acid derivatives with potential activity on dermal infections against selected microorganisms, including the facultative anaerobe C. acne. The peptides P1–P6 were synthesized via Fmoc solid phase peptide synthesis using Rink amide AM resin, analyzed by RP-HPLC-MS, FTIR, DPPH radical scavenging activity, and evaluated against C. acne and S. aureus, both deposited and non-deposited in BC. Peptides P1–P6 presented a lack of cytotoxicity, antimicrobial activity, or antioxidative properties correlated with selected structural properties. P2 and P4–P6 sorption in BC resulted in variable data, i.a., confirming the prospective topical application of these peptides in a BC carrier.     

改进型四碱光电阴极的结构研究

本文给出用新技术制作[Cs.Rb]Na_2KSb 结构的光电阴极,具有灵敏度高、热发射低和重复性好等优点,特别是改善了光电器件的性能。并提出了四碱光电阴极的复合表面能带结构模型,对上述的实验结果给予了满意的解释。     

Demonstration of a Broadband Photodetector Based on a Two-Dimensional Metal–Organic Framework

Metal–organic frameworks (MOFs) are emerging as an appealing class of highly tailorable electrically conducting materials with potential applications in optoelectronics. Yet, the realization of their proof-of-concept devices remains a daunting challenge, attributed to their poor electrical properties. Following recent work on a semiconducting Fe₃(THT)₂(NH₄)₃ (THT: 2,3,6,7,10,11-triphenylenehexathiol) 2D MOF with record-high mobility and band-like charge transport, here, an Fe₃(THT)₂(NH₄)₃ MOF-based photodetector operating in photoconductive mode capable of detecting a broad wavelength range from UV to NIR (400–1575 nm) is demonstrated. The narrow IR bandgap of the active layer (≈0.45 eV) constrains the performance of the photodetector at room temperature by band-to-band thermal excitation of charge carriers. At 77 K, the device performance is significantly improved; two orders of magnitude higher voltage responsivity, lower noise equivalent power, and higher specific detectivity of 7 × 10⁸ cm Hz^1/2 W⁻¹ are achieved under 785 nm excitation. These figures of merit are retained over the analyzed spectral region (400–1575 nm) and are commensurate to those obtained with the first demonstrations of graphene- and black-phosphorus-based photodetectors. This work demonstrates the feasibility of integrating conjugated MOFs as an active element into broadband photodetectors, thus bridging the gap between materials' synthesis and technological applications.     

光敏性类交替共聚物自组装及其应用

合成了光敏单体——对氯亚甲基苯乙烯与4-甲基-7-羟基香豆素的醚化产物(SC),并以SC为共聚单体与苯乙烯(St)和马来酸酐(MA)通过自由基共聚合成了双亲性类交替共聚物P(St/SC-alt-MA),再利用酸酐基元与2-氨基吡啶的胺解反应获得离子化的P(St/SC-alt-MA)(P(St/SC-alt-MAA))。用凝胶渗透色谱和核磁共振氢谱对P(St/SC-alt-MAA)的结构进行了表征;用激光粒度分析仪和透射电子显微镜表征了P(St/SC-alt-MAA)在选择性溶剂中自组装形成的胶束的结构;用紫外-可见分光光度计研究了不同辐照时间下P(St/SC-alt-MAA)胶束在特征紫外光波长处吸光度的变化。实验结果表明,P(St/SC-alt-MAA)胶束在365nm紫外光照射下发生光交联反应,在254nm紫外光照射下发生光解交联反应,说明P(St/SC-alt-MAA)胶束具备一定的光可逆特性。激光粒度分析仪和Zeta电位仪等测试结果显示,P(St/SC-alt-MAA)在选择性溶剂中形成了pH敏感的胶束,该胶束具有一定的乳化性能。     

甲基丙烯酸甲酯共聚物作为LIGA抗蚀剂的研究

设计合成具有头－头结构的甲基丙烯酸甲酯共聚物以及含大空间侧其的甲基丙烯酸甲酯共聚物,研究了它们为LIGA技术用抗蚀剂的光敏性能,结果表明适当大小空间侧基的引入,有助于改善烯酸甲酯抗蚀剂的光敏性。     

光纤光敏性的研究

研究和分析了用于制作光纤光栅的掺锗石英光纤的紫外光致折射率变化规律。在实验中利用248nm的脉冲准分子激光，对标准单模通信光纤，在不同曝光时间下进行紫外曝光，然后测量它们的径向折射率分布。实验结果表明：紫外光照射光纤的初始阶段，纤芯折射率直线上升，可用色心理论解释；紫外曝光的中间阶段，温度擦除效应对折射率变化的阻碍作用与色心形成改变折射率的作用相互竞争，折射率变化曲线出现起伏；实验的最后阶段，折射率变化再次呈上升趋势，可用紧缩／致密模型解释。光纤经过紫外光照射后折射率变化在10^-4数量级；曝光时间与光致折射率改变之闻存在非线性关系，并伴有饱和现象发生，样品的紫外光敏性、光致折射率的改变与紫外辐射时间有很大关系。     

Longitudinal Electrooptic Effects and Photosensitivities of Lead Zirconate Titanate Thin Films

The feasibility of storing and reading high-density optical information in lead zirconate titanate (PZT) and in lead lanthanum zirconate titanate (PLZT) thin films depends on both the longitudinal electrooptic coefficients and the photosensitivities of the films. This paper describes the methods used to measure the longitudinal electrooptic effects and the photosensitivities of the films. The results of these measurements were used to evaluate a longitudinal quadratic electrooptic R coefficient, a longitudinal linear electrooptic r_c coefficient, and the wavelength dependence of the photosensitivity of a composition of PZT polycrystalline thin film. The longitudinal electrooptic R and r_c coefficients are about an order of magnitude less than the transverse R and r_c coefficients of bulk ceramics of similar compositions. This is attributed to clamping of the film by the rigid substrate. The large birefringence of the films after poling (>10⁻²) suggests that the optic axes of the films are preferentially oriented normal to the film surface. The techniques used in this paper for evaluating the photosensitivities of thin films are based on measuring the photocurrent generated rather than the reduction in coercive voltage (as in bulk ceramics) when the film is exposed to light. The thin film photosensitivities appear to be significantly higher than those of bulk ceramics of similar compositions. The high photosensitivities coupled with the substantial longitudinal electrooptic coefficients combine to establish the feasibility of using PZT or PLZT thin films for optical information storage applications.     

基于氧化钨纳米纤维的紫外探测器

在本文中,我们通过在薄膜上收集多晶氧化钨(WO3)纳米线得到了高灵敏度的光电探测材料,并用X射线衍射,扫描电子显微镜和透射电子显微镜分别表征了材料的结构性能。紫外可见吸收光谱计算的结果显示纳米纤维在紫外区域有很强的吸收。在WO3纳米纤维中,我们观察到了高光敏特性。一种简易的组装方法被用于制备WO3纳米线器件。我们的研究结果显示WO3可以被用于紫外光探测器。 关键词：光探测器,纳米纤维,多晶,光敏性