A novel ionic‐conduction mechanism based on polyurethane electrolyte

A series of poly(ethylene glycol)–polyurethane (PEG–PU)/sodium perchlorate (NaClO₄) solid electrolytes were prepared, and their properties were characterized with Fourier transform infrared spectroscopy, differential scanning calorimetry, complex impedance analysis, and atomic force microscopy. Results showed that the oxygen atoms of carbonyl and ether oxygen groups had different activities on cations. Both carbonyl and ether oxygen groups participated in the ionic‐transport process in PU‐based electrolytes. There existed a coordination competition between sodium cations and different oxygen atoms in soft and hard segments of PU. For the PEG–PU/NaClO₄ system investigated, amorphous regions and interfacial regions between the amorphous and microcrystalline phases were responsible for ionic conduction. A new ionic‐transport mechanism, based on the existence of conduction pathways not only in amorphous regions but also in interfacial regions of microphase‐separated PU‐based electrolytes, is sketched. Moreover, at a particular concentration of doped salt (EO/NaClO₄ 12), the PEG–PU/NaClO₄ complex revealed a phase‐transition point in the morphology and exhibited minimum apparent activation energy and maximum ionic conductivity. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1246–1254, 2001     

Rapid fabrication and formation mechanism of cyclotriphosphazene-containing polymer nanofibers

Cyclotriphosphazene-containing polymer nanofibers with uniform diameters, high aspect ratios, and high specific surface area have been synthesized rapidly at high yields under ultrasonic irradiation via a self-directing template approach. During the polymerization, triethylamine (TEA) as an acid acceptor absorbed a byproduct hydrogen chloride (HCl) to afford triethylamine hydrochloride (TEACl), acting as structure-directing template and guiding the formation of nanofibrous structures. The mechanism was confirmed by means of SEM, TEM, FTIR, XRD, TG, and N₂ adsorption method. The molecular structure of as-synthesized polymer nanofibers was characterized by solid state NMR and elemental analysis.     

Violet/deep-blue fluorescent organic light-emitting diode based on high-efficiency novel carbazole derivative with large torsion angle

A novel and highly efficient violet/deep-blue fluorescent carbazole and naphthalene-based compound (1) is designed and synthesized. The compound shows intensive violet/deep-blue fluorescence, high photoluminescence efficiency (0.72 in CH₂Cl₂, 0.65 in film) and narrow full width at half maximum (48 nm). The large torsion angles between carbazole and naphthalene guarantee the weak intermolecular interactions and suppress the π-π interactions in solid state, resulting in the highly efficient violet/deep-blue fluorescence. The maximum emission peak, luminance and external quantum efficiency for violet/deep-blue electroluminescence are 410 nm, 1326 cd/m² and ～2%, respectively.     

自由基氧净电荷对过氧化物引发剂活性的影响

采用分子力学和半经验量子化学的方法 ,计算出了数十种有机过氧化物氧氧键均裂的键离解能 ,以及过氧化物生成的自由基的氧净电荷及其校正值 .数据的多重线性回归证明 ,影响有机过氧化物引发剂活性(常用 1 0h HLT表示 )的主要因素为自由基的电性和空间效应 ,这两者可以用自由基的氧净电荷及其校正值来表征 .在同种溶剂中 ,过氧化物生成的两个自由基的氧净电荷及其校正值 ,这四个因素与其半分解温度之间有较好的相关性 .这种相关性可以用来预测过氧化物的 1 0h HLT值 .     

含功能性羟基的温敏性聚(N-异丙基丙烯酰胺)微凝胶的制备及性能研究

采用两步合成路线合成了二缩三乙二醇单甲基丙烯酸酯 (TREGMA) ,并对其结构进行了表征 ;利用无皂乳液聚合法使N 异丙基丙烯酰胺 (NIPAM)、TREGMA和N ,N 亚甲基双丙烯酰胺 (BA)交联共聚 ,制备了含有功能性羟基的温敏性微凝胶 .微凝胶的去溶胀性能研究表明 ,TREGMA的引入使得微凝胶的体积相转变温度得到提高 ,同时所制得微凝胶具有较好的温敏性 .该类微凝胶有望成为良好的生物医用材料 .     

尼龙1010的远红外光谱研究

本文研究了结晶程度不同的尼龙1010远红外光谱的差异,对其谱带进行了经验归属。用分峰方法详细地研究了尼龙1010结晶程度的变化对其远红外谱带的位置、宽度和强度的影响。并对由不同退火方式得到的结晶样品的远红外光谱作了比较,由此证明了两者的结晶结构有所差异。     

脐橙香料、色素的提取及光谱研究

本文分别用水蒸气蒸馏法和溶剂浸出法从干脐橙皮中提取脐橙香料及脐橙色素与香料的混合物，测定了它们的紫外可见光吸收光谱、红外光谱。采用电感耦合等离子体原子发射光谱测定了该混合物中矿物质的含量。     

QSRR Study of GC Retention Indices of Volatile Compounds Emitted from Mosla chinensis Maxim by Multiple Linear Regression

The volatile compounds emitted from Mosla chinensis Maxim were analyzed by headspace solid‐phase microextraction (HS‐SPME) and headspace liquid‐phase microextraction (HS‐LPME) combined with gas chromatography‐mass spectrometry (GC‐MS). The main volatiles from Mosla chinensis Maxim were studied in this paper. It can be seen that 61 compounds were separated and identified. Forty‐nine volatile compounds were identified by SPME method, mainly including myrcene, α‐terpinene, p‐cymene, (E)‐ocimene, thymol, thymol acetate and (E)‐β‐farnesene. Forty‐five major volatile compounds were identified by LPME method, including α‐thujene, α‐pinene, camphene, butanoic acid, 2‐methylpropyl ester, myrcene, butanoic acid, butyl ester, α‐terpinene, p‐cymene, (E)‐ocimene, butane, 1,1‐dibutoxy‐, thymol, thymol acetate and (E)‐β‐farnesene. After analyzing the volatile compounds, multiple linear regression (MLR) method was used for building the regression model. Then the quantitative structure‐retention relationship (QSRR) model was validated by predictive‐ability test. The prediction results were in good agreement with the experimental values. The results demonstrated that headspace SPME‐GC‐MS and LPME‐GC‐MS are the simple, rapid and easy sample enrichment technique suitable for analysis of volatile compounds. This investigation provided an effective method for predicting the retention indices of new compounds even in the absence of the standard candidates.     

基于电化学安培法的中药降血糖活性成分筛选

为建立一种简单高效的中药活性成分的提取分离、定性鉴定、含量测定以及降血糖活性研究的新方法,采用绿色无毒的水提酸沉法提取了黄芩的活性成分-黄芩苷,通过薄层色谱法做定性鉴定和紫外分光光度法测定其含量,构建一个高效的电化学葡萄糖传感器,并建立一种基于电化学安培法的降血糖活性研究新方法。 以临床降糖药阿卡波糖论证了电化学安培法检测葡萄糖淀粉酶抑制活性的可靠性和稳定性,并成功应用于黄芩苷的降血糖活性研究。 结果表明,黄芩苷具有较好的葡萄糖淀粉酶抑制活性,其半数抑制浓度(IC₅₀)为0.056 g/L。 本研究为从天然药物中提取分离降血糖活性成分提供了一种新颖的研究方法。     

基于纯声子辐射模型的超薄绝缘夹层结构

在复合材料结构中起绝热、增韧作用的绝缘夹层,其加工厚度现在已达到纳米量级,原有的傅立叶热传导定律已无法描述其热能的传递行为,需从分子动力学、量子力学从发,针对不同研究对象建立相应的热传导模型．针对超薄绝缘夹层结构,将纯声子辐射模型和傅立叶热传导模型相结合数值求解热冲击条件下的温度场,并作为热载荷,用于求解结构上表面应力和夹层裂纹驱动力,其结果与只采用傅立叶热传导模型计算的结果相比较, 分析了物理参数对温度、应力和裂纹驱动力的影响．结果表明：与只采用傅立叶热传导模型计算的结果相比,按EPRT计算的热传导明显变慢,其表面剥离应力偏大,而夹层裂纹驱动力偏小．同时随着松弛时间增大和声子速度的降低,热传导减缓,表面横向剥离应力增大,超薄绝缘夹层内裂纹尖端驱动力减小．