导电聚合物有序超薄膜合成工艺的优化

采用Langmuir-Blodgett(LB)诱导沉积方法制备了不同层数的聚(3,4-乙烯二氧噻吩)/聚苯乙烯磺酸(PEDOT-PSS)导电复合膜。首次研究了十八胺(ODA)和十八胺/硬脂酸(SA)离子化单分子膜在PEDOT-PSS纳米粒子亚相及ODA/PEDOT-PSS组装体在纯水亚相上的成膜行为。实验表明:PEDOT-PSS纳米粒子对单分子层具有包裹作用,形成了稳定的复合单分子膜;不同膜压下制备的膜表面形貌不同,较高膜压下得到颗粒紧密排列的薄膜,亚相温度23℃,PEDOT-PSS浓度1×10-4mol/L,压缩速率5 mm/min,拉膜速率为1 mm/min的条件下薄膜具有较好的成膜性能。     

Langmuir and Langmuir‐Blodgett Asphaltene Films at Heptane‐water Interface

Monolayer characteristics of subfractions and unfractionated whole asphaltenes from Athabasca oil sands bitumen were studied at heptane‐water interface. The transferred Langmuir‐Blodgett films of asphaltenes were characterised with atomic force microscopy and contact angle measurements. Monolayers prepared from the three asphaltene samples are found to behave similarly at heptane‐water interface. The high molecular weight asphaltene monolayer is the most expanded one whereas the low molecular weight asphaltene monolayer is the most condensed one. An asphaltene monolayer behaves differently at an airwater interface to a heptane‐water interface. The presence of the bulk heptane phase renders the interfacial asphaltene monolayer more flexible as compared to that at air‐water interface.     

X-ray photoelectron spectroscopy study of Langmuir–Blodgett films of N-octadecyl-8-hydroxy-2-quinoline carboxamide deposited from subphases containing metal ions

The Langmuir–Blodgett films of N-octadecyl-8-hydroxy-2-quinoline carboxamide (HOQ) deposited from subphase containing metal ions were investigated by X-ray photoelectron spectroscopy (XPS). The amphiphilic HOQ with its complexing head group in contact with the aqueous phase can form metal complexes with the metal ions present in the aqueous phase. The formation of HOQ–metal complexes leads to the appearance of new XPS peaks assigned to the metal ions. The information on stoichiometry provided by XPS indicates that a metal ion is coordinated by one HOQ molecule for transition metal ions of the fourth period, but by two HOQ molecules for the metal ions after the fourth period.     

MLS结构的物理与电性能分析

本文从器件物理角度出发，深入研究了ＭＬＳ结构的Ｃ－Ｖ、Ｉ－Ｖ、界面、体内电荷、击穿等电学性能，并研制成功了一种新型的具有优良电性能的ＭＬＳ结构场效应晶体管，所得实验结果与理论相吻合。     

两亲性聚对苯乙撑的合成及其LB膜研究

本文通过wittig反应合成出了具有两亲性的聚对苯乙撑（PPV）类衍生物,通过核磁和红外对其进行了相关鉴定,并将其铺展上水面上,制得了稳定的单分子膜,并通过计算其单分子面积,研究了其分子在空气／水界面上的取向排列。在对多层LB膜的紫外光谱研究中发现,紫外吸光强度和层数成正比,说明该聚合物的单分子膜在转移过程中膜内分子的取向、构象及堆积方式没有随层数的增加而改变。     

辅酶Q_(10)分子与几种重要生物膜分子的相互作用

用LB膜技术与原子力显微镜技术(AFM)研究辅酶Q10与磷脂酰胆碱、磷脂酰乙醇胺、胆固醇等几种重要的生物膜分子的相互作用.实验发现,PC(PE)分子膜中加入辅酶Q10后,相变均出现延缓, 证明辅酶Q10位于疏水区,碳氢链伸入膜层当中,有可能起到抑制质子漏的作用.辅酶Q10与各重要生物分子的相互作用较为明显,辅酶Q10的加入增强了膜的通透性.     

Estimation of oxygen uptake rate of tomato (Lycopersicon esculentum Mill.) fruits by artificial neural networks modelled using near-infrared spectral absorbance and fruit mass

The oxygen uptake rate of tomato fruits was estimated by an artificial neural network (ANN) model using near-infrared (NIR) spectral absorbance and fruit mass. The absorption peak apex from cytochrome c oxidase (COX) was confirmed at 841 nm for mitochondrial preparation and at 833 nm for intact fruits. The results of a proteome analysis that detected the putative COX subunit II PS17 from the mitochondrial preparation biochemically supported the presence of the absorption peak due to COX. An ANN model for estimating O₂ uptake rate was developed from the absorbance data at 11 wavelengths from 645 to 979 nm including 833 nm and fruit mass as input variables. The O₂ uptake rate was estimated by the proposed model with a correlation coefficient of 0.79 and a standard error of prediction of 0.091 mmol kg⁻¹ h⁻¹. This method may be effective for rapid estimation of shelf life and physiological activity of tomato fruits.     

The lubrication property of LB films of cadmium salt of long chain fatty acids

In this paper, the authors have systematically studied the friction characteristics of various Langmuir-Blodett (LB) films of cadmium salts of long alkyl chain fatty acids. The parameters chosen were the number of layers of LB film, the load, and the sliding velocity. The results showed that there exists a range of numbers of layers for which a kinetic friction coefficient value (uk)as low as 0.02 is obtained. On the other hand, the friction coefficient in-creased gradually as the sliding velocity increased.     

Characterisation of a thermostable family 42 β-galactosidase (BgalC) family from Thermotoga maritima showing efficient lactose hydrolysis

A β-galactosidase gene (TM_1195) of Thermotoga maritima was cloned and expressed in Escherichia coli. The recombinant β-galactosidase (BgalC), belonging to glycosyl hydrolase (GH) family 42, was purified to homogeneity with 23.4-fold purification and a recovery of 36.6%. Its molecular mass was estimated to be 78 kDa by SDS–PAGE. BgalC exhibited maximum activity at an optimal pH of 5.5 and an optimum temperature of 80 °C. The enzyme displayed important properties, such as stability over a broad pH range of 5.0–9.0 and thermostability up to 75 °C. K_m values of BgalC for p-nitrophenyl-β-galactopyranoside (pNPGal), o-nitrophenyl-β-galactopyranoside (oNPGal) and lactose were 1.21, 7.31 and 6.5 mM, respectively. BgalC was efficient in complete removal of lactose from milk. BgalC is significantly one of the few β-galactosidases from family 42 displaying significant hydrolysis of lactose. These properties make BgalC an ideal candidate for commercial use, in the production of lactose-free milk.     

单壁碳纳米管在LB培养基及生理盐水中的抗菌性研究

测定了单壁碳纳米管(SWNTs)在生理盐水及LB培养基中对革兰氏阳性菌枯草芽孢杆菌(B.subtilis)的抑菌率,探讨了SWNTs的抑菌机理及培养基对SWNTs抑菌性的影响。用扫描电镜(SEM)、透射电镜(TEM)对有无LB(Luria-Bertani)培养基的SWNTs进行了表征。结果表明:SWNTs的抑菌性受环境影响,在生理盐水及LB培养基中,抑菌性能表现迥异。