柔性间隔基对于香豆素取代二乙炔LB膜聚合及手性形成的影响

设计合成了2种香豆素取代二乙炔单体,7-(10,12-二十三双炔酰氧基)-香豆素(CODA)和7-(10,12-二十三双炔酰氧乙氧基)-香豆素(CO2DA),研究了柔性间隔基对香豆素取代二乙炔单体在气-液界面的组装、单体LB膜的聚合以及聚二乙炔主链螺旋结构形成的影响.利用Langmui-Blodgett(LB)技术,以纯水为亚相,膜压在35 mN/m时沉积制备了香豆素取代二乙炔单体LB膜.尽管CODA是非手性的,但其LB膜均表现出明显的宏观手性信号.这是由于在压缩过程中香豆素基团间强烈的π-π堆积,形成了螺旋排列,显示出超分子手性.而CO2DA LB膜无明显CD信号.经254 nm紫外光辐照,CODA LB膜聚合成蓝相,聚二乙炔主链表现出明显的宏观手性.而CO2DA LB膜聚合后无明显的CD信号.薄膜中香豆素功能基团的不规则排列不利于二乙炔单体的固态聚合以及聚二乙炔主链螺旋结构的形成.     

5,12-二硫杂-7,14-二氮杂-5,7,12,14-四氢并五苯及其相关化合物二阶非线性光学性质的理论研究

在ZINDO方法基础上,按完全态求和(SOS)公式编制了计算分子二阶非线性光学系数β_ijk、β_u的程序.研究了不同取代基在5,12-二硫杂-7,14-二氮杂-5,7,12,14-四氢并五苯侧环取代衍生物及相关化合物的结构、光谱和二阶非线性光学性质。结果表明:侧环上取代推、拉电于基团对增大二阶光学非线性都有利;分子共平面,共轭作用强,对增大二阶光学非线性有利.     

2-十八烷基-7,7,8,8-四氰基对醌二甲烷和3,3′,5,5′-四甲基联苯胺电荷转移配合物LB膜的制备和表征

利用LB技术制备了2-十八烷基-7,7,8,8-四氰基对醌二甲烷(C18TCNQ)和3,3,′5,5′-四甲基联苯胺(TMB)的电荷转移配合物(CT comp lex)薄膜,即TMB.C18TCNQ LB膜.利用红外(IR)光谱、紫外-可见-近红外(UV-V is-NIR)光谱以及原子力显微镜(AFM)研究了TMB.C18TCNQ在LB膜中的分子取向、结构及表面形貌.结果表明,配合物为混合堆积类型,LB膜中电子给体TMB和电子受体C18TCNQ的环面分别垂直于固体基板表面,而且给体和受体以面对面的方式堆积.5层TMB.C18TCNQ LB膜的AFM照片显示,其表面形貌是由许多堆积在一起的六边形片状微晶组成的,微晶的宽度约为180 nm.与通过LB技术和掺杂技术制备的TMB.C18TCNQ掺杂膜比较,TMB.C18TCNQ LB膜具有明显不同的结构,其长的脂肪烃链有向垂直于基板表面方向变化的趋势,LB膜与掺杂膜的表面形貌也有明显不同.这表明不同的制备方法可以影响薄膜的结构和形貌.     

两亲性卟啉-紫精化合物LB膜的结构及光电性质研究

本文制备了两亲性卟啉-紫精化合物的LB膜材料, 用π-A等温曲线、吸收光谱、小角和低角X射线衍射以及扫描隧道电镜(STM)等方法研究了LB膜的结构。结果表明, LB膜内分子排列是二维有序的超晶格结构, 卟啉环在基片上的排列呈"站立"状态。单个分子占有面积为1.15nm^2, 单层高度为2.35nm, 相邻裂间的距离为1.07nm。这种规则有序的两亲性卟啉-紫精化合物呈现出良好的光量子收率和光电响应特性。     

8,10-二炔廿五碳酸LB膜的周期结构

合成了8,10-二炔廿五碳酸,在玻璃片、石英片和镀金片上沉积了它的LB膜,X-射线衍射研究了LB膜的周期结构和聚合对它的影响。在2θ=1°—15°范围内观察到了多达7个布拉格衍射峰。由此计算了等同周期和分子在基片上的倾斜角。用分子模型计算了衍射峰强度,得到了与实验结果相符合的衍射峰强度奇偶起伏现象。     

8-羟基喹啉两亲配合物的LB膜及其电致发光器件研究

制备了两亲配体N-十六烷基-8-羟基-2-喹啉甲酰胺(HL)十个配合物的LB膜。采用π-A等温线和小角X射线衍射等方法研究了这些LB膜的性质和结构。两亲配合物的单分子占有面积为(1.25±0.06)nm^2和(0.75±0.06)nm^2,分别对应于两亲分子中两个喹啉环平躺和环与环之间以一定的角度倾斜于气/水界面。LB膜内分子排列是二维有序的超晶格结构,双层高度(5.0±0.1)nm;LB膜具有导电各向异性,其平面和垂直直流电导率分别为10^-^5S.m^-^1和10^-^9S.m^-^1;LB膜的高荧光性质使之可以用作为电致发光器件的发光材料。以LaL~2(H~2O)~4Cl的LB膜为发光层的单层电致发光器件的驱动电压为9V,发光亮度330cd/m^2,为黄绿色发光。     

二维蛋白质分子印迹聚合物*

本文对二维蛋白质分子印迹进行了综述：介绍了二维蛋白分子印迹的基本概念;阐述了常见二维蛋白质分子印迹方法的基本原理,包括表位印迹法、溶胶-凝胶法、射频光电等离子沉积法和Langmuir单层法等;根据二维蛋白分子印迹材料的不同形式,详细叙述了二维蛋白质分子印迹薄膜、核-壳微球、纳米线、Langmuir脂质体单层的制备过程、结合能力、选择识别性能;分析了目前二维蛋白质分子印迹技术存在的一些不足和进一步研究的方向。     

由组分可控的LB膜前驱物法制备Y2O3稳定立方相ZrO2的超薄陶瓷膜

由有机LB膜技术发展了一种制备组分、厚度可控的无机超薄陶瓷膜的方法.以Zr、 Y的β-二酮络合物的作为"表面离子"代替传统的亚相离子,沉积它们与花生酸的混合LB膜.并将它作为前驱物,经臭氧处理和热处理,成功制得了Y2O3稳定的立方相ZrO2超薄膜(YSZ).用X射线衍射(XRD)、 X射线光电子能谱(XPS)等手段研究了YSZ薄膜的相结构和其组成.结果表明,超薄陶瓷膜中Zr与Y的含量比率控制得很好,且形成Y2O3稳定的立方相ZrO2.说明这种方法可以成功地用来制备组分和膜厚均可控的纳米陶瓷膜.     

一新种型含肉桂酸的Bola型两亲分子在LB膜中的分子排列和分子识别

制备了一种含肉桂酸基团的Bola型两亲分子HDC(4-(10-羟基癸氧基)-10-羟基癸氧基肉桂酸酯). 该分子在空气/水界面形成多分子层Langmuir膜结构. 紫外光照可使膜中HDC分子发生光致二聚，也可使HDC与1,16-十六碳二醇形成的混和膜中HDC分子发生二聚. 光照前后膜中分子倾角分别为58.8°和53.2°. 从实验结果推测了分子排列模型，认为HDC分子在LB膜中有序排列，这来源于分子间π-π相互作用和疏水亚甲基链的Z型构象堆积.     

TS单晶体及其聚合物PTS的介电和动态力学行为

<正> 聚丁二炔类宏观单晶体以其极大的尺寸,完整性和立体规整的共轭主链,为我们提供了一个准一维体系模型化合物。它们的电性能,非线性光学性能及形成聚合LB膜的能力等具有潜在的应用前景,近年来研究工作非常活跃。丁二炔类化合物中最能培养咸大晶体,从而研究得最多的是双(对甲苯磺酸)-2,4-己二炔-1,6-二醇酯(TS)及其聚合物PTS。我们先后测量过它们的热电势率、电导、膨胀系数、介电性能、光声效     

纳米二氧化硅粒子对聚氯乙烯膜的表面结构及浸润性能的调控作用

报道了一种简便的调控聚合物材料表面结构及浸润性能的方法.利用流延成膜和纳米二氧化硅粒子的印迹修饰作用,制备出3种具有不同表面结构的聚氯乙烯(PVC)膜,膜的浸润性能表现为与水的接触角从103°的疏水性变为65°的亲水性,再改变至130°的疏水性.扫描电镜结果表明印迹修饰后的PVC膜具有纳米和微米尺寸的凹凸表面结构.通过对比实验证实了溶剂氯仿和NaOH溶液并不影响膜表面的疏水性能.     

Preparation and properties of alkoxy(methyl)silsesquioxanes as coating agents

Polysilsesquioxanes were prepared through the acid‐catalyzed hydrolytic polycondensation of triethoxy(methyl)silane, triisopropoxy(methyl)silane, or triisobutoxy(methyl)silane and subjected to dip coating to form coating films. The film formation depended on the polarity and crystallinity of the substrate, and a correlation was found between the substrate and polysilsesquioxane solubility parameters. When the coating film was heated, thermal condensation occurred at about 500 °C between hydroxy groups or between hydroxy and alkoxy groups. The methyl group attached to silicon decomposed, and siloxane bonding formed at about 800 °C. The adhesion and hardness of the coating films were evaluated with the Japanese Industrial Standard K5400 protocol, and they increased with increases in the heating time and heat‐treatment temperature. The refractive index of the coating films decreased when the heat‐treatment temperature was increased to 500 °C because of the combustion of organic groups. In contrast, the surface electric resistance increased with the heat‐treatment temperature up to 500 °C. The dielectric constant was 2.6–2.8 and decreased with an increases in the molecular weight and the degree of crosslinking of the polysilsesquioxanes. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3676–3684, 2004     

表面接枝含氟苯乙烯共聚物的聚酯薄膜制备与表征

利用表面引发原子转移自由基聚合(SI-ATRP)在聚对苯二甲酸乙二醇酯(PET)薄膜表面接枝苯乙烯和4-氟苯乙烯的共聚物.研究不同反应时间和不同配比下接枝共聚物对聚酯薄膜表面组成、结构和性能的影响.通过傅利叶变换红外光谱仪(ATR/FTIR),X-射线光电子能谱仪(XPS),凝胶渗透色谱(GPC)和扫描电子显微镜(SEM)对接枝改性前后PET薄膜的表面组成,结构和形貌进行分析;利用接触角测试和表面能计算对比研究接枝改性前后PET薄膜的表面性能.结果表明反应时间和单体百分含量对接枝百分率及接触角有一定的影响,随着反应时间的增长,聚酯薄膜表面接枝百分率增大,接触角增加,表面自由能下降.     

聚酰亚胺LB膜热解制备SiC薄膜的XPS研究

用XPS对沉积在硅基片上的聚酰亚胺LB膜以及由它真空热解制备的SiC薄膜进行了研究 ,并对其形成过程进行了跟踪分析 .XPS结果显示聚酰亚胺LB膜结构均匀 ,质量良好 ;真空热解时 ,约在 6 70℃时LB膜中的C与衬底Si反应形成SiC ;Ar离子溅射深度俄歇谱表明所制备的SiC膜中Si和C浓度成梯度分布 ,说明SiC是由Si和C相互扩散反应形成的     

Oxidation Behaviour of PACVD-(Ti,Al)N Wear Resistance Layers

 Sputtered (Ti,Al)N hard coatings are successfully used for dry high speed cutting. These films show a lower oxidation rate than TiN or TiC coatings. In our work (Ti,Al)N films were deposited on WC-6%Co substrates at a temperature of 490°C by plasma-assisted chemical vapour deposition (PACVD) using a gas mixture of TiCl₄/AlCl₃/N₂/Ar/H₂. Investigation of microstructure, crystalline structure and chemical composition was carried out using SEM, WDXS, TEM, AES and XRD techniques. The chemical composition of the deposited films showed a Al to Ti ratio of 1.33. The film thickness was 5.5 μm. Films showed a fine crystalline size, the metastable fcc crystal structure and a columnar growth. The film surface was under low compressive stress up to several 100 MPa. For (Ti,Al)N/WC-Co compounds the oxidation behaviour up to 1100°C (high temperature range) was studied. Therefore, samples were annealed or rapidly heated in air and under high vacuum condition using the laser shock method. The results show decomposition of the (Ti,Al)N structure to the TiN and the AlN phases at temperature values above 900°C. Heating in air causes growing of a thin aluminum oxide layer at the film surface, which is a barrier for further oxygen diffusion to the alumina-film boundary. Additionally, at temperatures above 900°C oxidation of the WC-6%Co substrate surface was obtained in regions of opened cracks and film delamination.     

聚氧化丙烯醚对SiO2减反膜性质的影响

采用溶胶-凝胶制备的SiO2减反膜具有优良的光学特性和高损伤阈值,可以用做高反膜和减反膜的低折射率匹配层.在高功率激光领域具有十分诱人的应用前景.     

Residual stress and optical properties of fully rod-like poly(p-phenylene pyromellitimide) in thin films: Effects of soft-bake and thermal imidization history

A soluble poly(amic acid) precursor solution of fully rod-like poly(p-phenylene pyromellitimide) (PMDA-PDA) was spin cast on silicon substrates, followed by soft bake at 80–185°C and subsequent thermal imidization at various conditions over 185–400°C in nitrogen atmosphere to be converted to the polyimide in films. Residual stress generated at the interface was measured in situ during imidization. In addition, the imidized films were characterized in the aspect of polymer chain orientation and ordering by prism coupling and X-ray diffraction. The soft-baked precursor film revealed a residual stress of 16–28 MPa at room temperature, depending on the soft bake condition: higher temperature and longer time in the soft bake gave higher residual stress. The stress variation in the soft-baked precursor film was not significantly reflected in the final stress in the resultant polyimide film. However, the residual stress in the polyimide film varied sensitively with variations in imidization process parameters, such as imidization temperature, imidization steps, heating rate, and film thickness. The polyimide film exhibited a wide range of residual stress, −7 MPa to 8 MPa at room temperature, depending on the imidization condition. Both rapid imidization and low-temperature imidization generated high stress in the tension mode in the polyimide film, whereas slow imidization as well as high temperature imidization gave high stress in the compression mode. Thus, a moderate imidization condition, a single- or two-step imidization at 300°C for 2 h with a heating rate of < 10 K/min was proposed to give a relatively low stress in the polyimide film of < 10 μm thickness. However, once a precursor film was thermally imidized at a chosen process condition, the residual stress–temperature profile was insensitive to variations in the cooling process. All the films imidized were optically anisotropic, regardless of the imidization history, indicating that rod-like PMDA-PDA polyimide chains were preferentially aligned in the film plane. However, its degree of in-plane chain orientation varied on the imidization history. It is directly correlated to the residual stress in the film, which is an in-plane characteristic. For films with residual stress in the tension mode, higher stress films exhibited lower out-of-plane birefringence, that is, lower in-plane chain orienta-tion. In contrast, in the compression mode, higher stress films showed higher in-plane chain orientation. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1261–1273, 1998     

Evaluation of poly(4‐methyl‐1‐pentene) as a dielectric capacitor film for high‐temperature energy storage applications

Poly(4‐methyl‐1‐pentene) (P4MP) was characterized to evaluate its viability as a high‐temperature dielectric film for capacitors. Detailed investigation of thermal, mechanical, rheological, and dielectric properties was carried out to assess its high‐temperature performance and processability. P4MP was melt‐processable below 270 °C without degradation and application temperatures as high as 160–190 °C can be achieved. The dielectric constant and loss of melt‐processed P4MP films was comparable to biaxially oriented polypropylene (BOPP) capacitor films, although the dielectric strength was lower. Enhancements in dielectric strength up to 250–300% were achieved via solution‐processing P4MP films, which could be easily scaled up on a roll‐to‐roll platform to yield isotropic, free‐standing films as thin as 3–5 μm. The influence of crystal structure, crystallinity, and surface morphology of these films on the dielectric properties was examined. The dielectric strength was further increased by 450% through biaxial stretching of solution‐cast films, and a Weibull breakdown field of 514 V/μm was obtained. The dielectric constant was very stable as a function of frequency and temperature and the dielectric loss was restricted to <1–2%. Overall, these results suggest that BOP4MP is a promising candidate to obtain similar energy density as a BOPP capacitor film but at much higher operating temperatures. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1497–1515     

Synthesis and characterization of (hydroxypropyl)cellulose/TiO2 nanocomposite films

A new method of synthesis of TiO₂ nanoparticles as well as preparation of the organic–inorganic hybrid nanocomposite films of (hydroxypropyl)cellulose (HPC)/TiO₂ is presented. At the first stage, the oxotitanium hydrogel phase was obtained by the mineralization of (tetra‐isopropyl)orthotitanate (TIPT) modified by the methacrylic acid (MAA) in 15 wt% solution of H₂O₂ at room temperature and subsequent annealing at the temperature of 85°C. The crystallization of the nanoparticles of TiO₂ was conducted at the oxotitanium hydrogel phase at temperatures around 120°C in the closed vessel. Nanocomposite hybrid films were prepared by the casting method from a solution of HPC and TiO₂ nanoparticles in the water. The films of nanocomposite with 10 µm thickness are transparent to visible light and have a lower glass transition temperature compared with HPC in the bulk. This shift of the glass transition is interpreted in terms of packing density of HPC in the interface of HPC nanocomposite with TiO₂. The X‐ray diffraction pattern of the nanocomposite film suggests a lower amount of mesomorphic phase of HPC in the composite compared with HPC in the bulk. Copyright © 2007 John Wiley & Sons, Ltd.     

Amorphous silicon carbonitride thin‐film coatings produced by remote nitrogen microwave plasma chemical vapour deposition using organosilicon precursor

Amorphous silicon carbonitride (a‐SiCN) films were produced by remote nitrogen plasma chemical vapour deposition (RP‐CVD) from bis(dimethylamino)methylsilane precursor. The effect of substrate temperature (T _S) on the kinetics of RP‐CVD, chemical structure, surface morphology and some properties of the resulting films is reported. The T _S dependence of film growth rate implies that RP‐CVD is an adsorption‐controlled process. Fourier transform infrared spectroscopic examination revealed that an increase in T _S from 30 to 400°C involves the elimination of organic moieties from the film and the formation of Si─C and Si─N network structure. The films were characterized in terms of their surface roughness and basic physical and optical properties, such as density and refractive index, respectively. Reasonably good relationships between the structural parameters represented by relative integrated intensity of infrared absorption bands from the Si─C and Si─N bonds (controlled by T _S) and the film properties are determined. Due to their small surface roughness, high density and high refractive index, the a‐SiCN films produced at T _S ≥ 350°C would seem to be useful protective coatings for metals and optical devices.