溶胶-凝胶薄膜修饰的微结构聚合物光纤氟离子传感探头

通过对微结构聚合物光纤修饰桑色素-铝配合物掺杂的凝胶薄膜,制备了一种氟化物光纤传感探头。这种探头的结构基于微结构聚合物光纤实现,其内部具有贯穿的微孔道结构,这种微孔道结构可以作为敏感材料的载体以及微传感池。敏感层的修饰通过溶胶-凝胶过程实现,将掺有桑色素-铝的溶胶直接吸入光纤内部,可以在光纤微孔阵列中形成凝胶敏感膜。微结构光纤内部可以容纳微量液体,传感过程在微孔道内进行。基于荧光淬灭原理实现传感,氟离子对凝胶膜中桑色素-铝具有强烈的荧光淬灭作用,因此,传感探头对于不同浓度的氟离子溶液表现不同的荧光强度。在pH值为4.6的条件下,探头对于氟离子具有良好的响应,可在5～50mmol/L内传感。     

原位溶胶-凝胶法合成纳米SiO_2润滑液的摩擦学性能

采用溶胶-凝胶法在亲水性聚醚油中原位制备纳米二氧化硅微球。利用透射电镜系统考察反应条件,如氨水和水的添加量、正硅酸乙酯(TEOS)添加量、聚醚含量及水解温度对原位生成的纳米二氧化硅颗粒的直径和形貌的影响。结果表明:随着TEOS、氨水及水含量的增加,纳米二氧化硅颗粒直径逐渐增大;而随着聚醚油含量增加以及反应温度的升高,纳米二氧化硅颗粒直径逐渐减小直至出现严重团聚。使用四球摩擦磨损试验机,研究不同粒径的纳米二氧化硅微球对润滑油减摩抗磨性能的影响。结果表明,随着纳米颗粒添加量的增加其摩擦因数和磨斑直径呈现出先下降后上升的趋势;在纳米颗粒最佳添加量时,纳米颗粒直径越小其减摩抗磨效果越明显;同时,纳米二氧化硅润滑液具有优异的减摩抗磨性能,但其最佳添加量受颗粒直径影响呈非规律性变化。     

桑色素-Al掺杂的溶胶-凝胶薄膜修饰的MPOF光纤氟离子传感探头

本文通过对微结构聚合物光纤修饰桑色素-铝配合物掺杂的凝胶薄膜,制备了一种氟化物光纤传感探头。这种探头的结构基于微结构聚合物光纤实现,其内部具有贯穿的微孔道结构,这种微孔结构可以作为敏感材料的载体以及微传感池。敏感层的修饰通过溶胶-凝胶过程实现,将掺有桑色素-铝的溶胶直接吸入光纤内部,可以在光纤微孔阵列中形成凝胶敏感膜。微结构光纤内部可以容纳微量液体,传感过程在微孔道内进行。传感原理基于荧光淬灭远离实现,氟离子对凝胶膜中桑色素-铝具有强烈的荧光淬灭作用,因此传感探头对于不同浓度的氟离子溶液表现不同的荧光强度。在pH值为4.6的条件下,探头对于氟离子具有良好的响应,其传感范围为5-50mmol/L。     

溶胶-凝胶法制备铁电薄膜的研究进展

溶胶-凝胶法是制备铁电薄膜的一种重要方法。综述了溶胶-凝胶法制备铁电薄膜的原理、工艺过程、特点,以及采用此方法制备出的某些材料的铁电性能。最后指出,溶胶-凝胶法制备铁电薄膜工艺仍需优化和改进,薄膜的质量亟待提高,以适应器件的要求。     

溶胶-凝胶法制备铁电薄膜的研究进展

溶胶-凝胶法是制备铁电薄膜的一种重要方法.综述了溶胶-凝胶法制备铁电薄膜的原理、工艺过程、特点,以及采用此方法制备出的某些材料的铁电性能.最后指出,溶胶-凝胶法制备铁电薄膜工艺仍需优化和改进,薄膜的质量亟待提高,以适应器件的要求.     

溶胶-凝胶法制备纳米SiO2超细粉体

利用阴、阳离子交换法制备了能长期稳定存在的、粒径可控的、高浓度的硅溶胶，并通过溶胶-凝胶法制备了纳米SiO2超细粉体。通过在凝胶过程中滴加稳定剂的方法成功地解决了SiO2颗粒的团聚问题，为下一步制备高聚物/无机物纳米复合涂层创造了条件。     

乙二胺四乙酸络合溶胶-凝胶法制备CuFeMnO_4尖晶石复合金属氧化物

采用乙二胺四乙酸(EDTA)络合溶胶一凝胶法制备了CuFeMnO4尖晶石复合金属氧化物,用TG-DTA、IR、XRD、SEM等仪器对其干凝胶的热分解过程、产物物相结构、微观形貌和太阳光吸收率等进行了分析表征.结果表明:制备的干凝胶在442℃以上已基本分解完全;经600℃煅烧晶化后形成CuFeMnO4尖晶石复合金属氧化物,平均晶粒尺寸在14 nm左右,但纳米颗粒已严重团聚,形成大的颗粒;所获得的复合金属氧化物粉体对200～2 500 nm波长范围的太阳光吸收率约为85.435%.     

铁-镍纳米粉末的制备及其表征

通过差热分析、透射电镜和X射线衍射分析等方法，对以硝酸铁和硝酸镍为主要原料，采用溶胶-凝胶法和化学共还原法制取的镍质量分数分别为10％和20％的铁-镍纳米粉末进行了表征，同时比较聚乙二醇和柠檬酸在制备凝胶时的分散效果。结果表明：以柠檬酸为分散剂，制备的铁-镍纳米粉末的粒径在：30nm左右，成分为(Fe，Ni)和少量(Ni，Fe)Fe2O4的混合物，无其他杂质。     

溶胶-凝胶法制备YBCO超导材料

采用胶溶法、缓释反应法和Pechini工艺等三种不同的溶胶 凝胶方法制备YBCO超导材料,观测了合成物的结构以及超导性能等。结果表明:Pechini工艺制备的粉体纯度高,颗粒细小、均匀,经960℃长时间烧结后,可获得高纯度的YBCO超导材料,超导临界转变温度Tc=92K,跃迁宽度ΔT<1K。     

溶胶-凝胶法制备三氧化钼电致变色薄膜的研究

以钼的异丙醇盐为前驱体,用溶胶—凝胶法制备了MoO3电致变色膜。在不同温度下对样品进行热处理。用扫描电镜和X-射线衍射对热处理后的薄膜进行表面形貌和微观结构分析,结果显示薄膜在150°C退火为非结晶态,250°C退火部分结晶。对非晶态薄膜的光学性质研究表明,非晶态MoO3薄膜在可见光区具有较好的变色特性,550nm处透过率ΔT为33%。     

疏水SiO2宽频增透膜的制备与研究

采用溶胶-凝胶浸渍提拉工艺在玻璃表面制备了双层增透膜,该薄膜由折射率分别为1.12和1.33的两层膜构成。薄膜在380~1 100nm和1 100~2 500nm范围内平均透过率较空白玻璃分别提高了7.68%和4.39%。薄膜接触角大约141°,且表层膜在2个月内能保持较高的疏水效果。双层增透膜制备方法简单,在宽光谱耐环境减反射领域有一定的应用潜力。     

TiO2薄膜电极光电转换性能的影响因素

采用溶胶-凝胶法在玻璃基体表面制备了不同粒径的TiO2薄膜和纳米SnO2/TiO2复合薄膜,将它们与不同对电极进行了光电转换性能测试.结果表明:氧化物薄膜电极经染料敏化、薄膜颗粒细化及薄膜复合化都有利于提高电极的光电转换性能.用汞溴红敏化后,粒径为25 nm的TiO2薄膜的光电转换性能提高了847倍;粒径为25 nm的TiO2薄膜的光电转换性能是粒径为136 nm的TiO2薄膜的5倍;粒径为25 nm的TiO2薄膜经粒径为27 nm的SnO2薄膜复合后,其光电转换性能提高了7.7%.     

Immobilization of proteins on self-assembled monolayers

The immobilization of protein molecules on self-assembled monolayers (SAM) by physical interactions and chemical bonding has been studied using atomic force microscopy (AFM). The proteins used for our investigation are bovine serum albumin (BSA), lysozyme (LYZ), and normal rabbit immunoglobulin G (IgG). The surfaces are methyl-, hydroxyl-, carboxylic acid- and aldehyde-terminated SAMs. We found that BSA and LYZ can be readily immobilized on SAMs at their isoelectric point (IEP). The detailed surface morphology of adsorbed proteins varies with the functionality of the SAMs. The strong hydrophobic interaction at the IEP is attributed to immobilization. If the solution pH is deviated from the IEP, proteins may be attached onto the surface via electrostatic interactions. Covalent binding between the aldehyde-terminated SAM and the H2N-groups in the protein results in immobilization of all three proteins. The individual proteins and their orientations on SAMs are clearly resolved from high-resolution AFM images. The stability and bioactivity of these immobilized proteins are also studied.     

Nanomechanics of biomolecules: focus on DNA

Nano-mechanical measurements and manipulations at the single-cell and single-molecular levels using the atomic force microscope (AFM) and optical tweezers are presenting fascinating opportunities to the researchers in bioscience and biotechnology. Single molecule biophysics technologies, due to their capability to detect transient states of molecules and biomolecular complexes, are the methods of choice for studies in DNA structure and dynamics, DNA-DNA and DNA-protein interactions, and viral DNA packaging. The aim of this review is to describe the recent developments of scientific tools and the knowledge gained in single molecule DNA mechanics such as DNA elasticity, electrostatics, condensation and interactions of DNA with surrounding fluids during its hydrodynamic flow. This paper was presented at the 9^th Asian International Conference on Fluid Machinery (AICFM9), Jeju, Korea, October 16–19, 2007.recommended for publication in revised form by Associate Editor In-Ha Sung Y. Eugene Pak is currently serving as the Director of Research Planning Team at the Advanced Institute of Convergence Technology in Seoul National University. He received B.S. degree in Mechanical Engineering from the State University of New York at Buffalo in 1980, and M.S. and Ph.D. degrees in Mechanical Engineering from Stanford University in 1982 and 1985, respectively. After obtaining the Ph.D. degree, he worked as Senior Research Scientist at Northrup-Grumman Corporate Research Center. He joined the Samsung Advanced Institute of Technology (SAIT) in 1995 and has since been leading and expanding research programs in MEMS, Nano and Biotechnology. Sanghyo Kim received B.S. degree in Polymer Science and Engineering from Pusan National University in 1986. He then went on to receive his M.S. and Ph.D. degrees from POSTECH in 1992 and1996, respectively. After the Ph.D. degree, he worked as Senior Researcher at University of Sheffield, UK and University of Cincinnati, USA. He joined the Samsung Electronics Ltd. as a principal researcher in 2002. Dr. Kim is currently an Assistant Professor at the College of Bionano Technology, Kyungwon University in Gyeonggi, Korea. His research interest is in the area of pervasive healthcare information technology including ubiquitous healthcare system and cell/tissue based lab-on-a-chip. Mohana Marimuthu received her Bachelor degree in Pharmacy from The TamilNadu Dr. M.G.R Medical University, India, in 2007. She worked as a clinical study coordinator in phase III clinical trials (Asthma and Chronic Obstructive Pulmonary Disease) at pulmonary department in Sri Ramakrishna Hospital and Institute of Health science, India until February 2008. She is currently doing final year M.S degree in Bionanotechnology at Kyungwon University, Korea. Her research interests extend into microfluidics, tissue engineering and drug delivery.     

Quantitative interrogation of micropatterned biomolecules by surface force microscopy

Synthetic biomaterials are widely used in medical implants with success in improving and extending quality of life. However, these materials were not originally designed to interact with cells through specific signaling pathways. As a result, the interaction with the body is mediated through passive adsorption of a disorganized protein monolayer. Next generation biomaterials have been proposed to be active in modifying the biological response of the host through the incorporation of specific biorecognition moieties. An important tool in the development of these novel active biomaterials is the scanning force microscope (SFM). The SFM allows for interrogation of bioactive biomaterials in mapping or spectroscopic modes. In this work, micropatterned protein surfaces were prepared using biomolecules implicated in wound healing. The surfaces were imaged via SFM and the specific binding forces between surface associated biomolecules and antibody functionalized tips were quantified.     

Resolving the geometry of biomolecules imaged by cryo electron tomography

In this paper, we describe two methods for computerized analysis of cryo electron tomography reconstructions of biomolecules. Both methods aim at quantifying the degree of structural flexibility of macromolecules and eventually resolving the inner dynamics through automatized protocols. The first method performs a Brownian dynamics evolution of a simplified molecular model into a fictitious force field generated by the tomograms. This procedure enables us to dock the simplified model into the experimental profiles. The second uses a fuzzy framework to delineate the subparts of the proteins and subsequently determine their interdomain relations. The two methods are discussed and their complementarities highlighted with reference to the case of the immonoglobulin antibody. Both artificial maps, constructed from immunoglobulin G entries in the Protein Data Bank and real tomograms are analyzed. Robustness issues and agreement with previously reported measurements are discussed.     

锑掺杂纳米SnO2透明导电薄膜的制备与性能研究

采用溶胶-凝胶法在Si片、已镀SiO2的钠钙硅玻璃和普通钠钙硅玻璃上镀Sb掺杂摩尔分数为8%的SnO2薄膜(ATO),在450℃热处理温度下对薄膜结构,电学、光学性能进行表征。结果表明:薄膜以四方金红石结构存在,结晶完全;方阻值随镀膜层数的增加而明显降低,12层时薄膜最低方阻值为129Ω/□,可见光平均透过率在75%以上。随着波长的增大,红外波段的反射率逐渐增大,从15%增加到55%左右。     

AFM characterization of biomolecules in physiological environment by an advanced nanofabricated probe

Many relevant questions in biology and medicine require both topography and chemical information with high spatial resolution. Several biological events that occur at the nanometer scale level need to be investigated in physiological conditions. In this regard Atomic Force Microscopy (AFM) is one of the most powerful tools for label‐free nanoscale characterization of biological samples in liquid environment. Recently, the coupling of Raman spectroscopy to scanning probe microscopies has opened new perspectives on this subject; however, the coupling of quality AFM spectroscopy with Raman spectroscopy in the same probe is not trivial. In this work we report about the AFM capabilities of an advanced high‐resolution probe that has been previously nanofabricated by our group for coupling with Raman spectroscopy applications. We investigate its use for liquid AFM measurements on biological model samples like lipid bilayers, amyloid fibrils, and titin proteins. We demonstrate topography resolution down to nanometer level, force measurement and stable imaging capability. We also discuss about its potential as nanoscale chemical probe in liquid phase. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.     

基于摩擦学带沟槽滑块的摩擦系数试验研究

根据摩擦学原理,针对往复式滑块运动特点,设计了一种带沟槽滑块,并进行了理论计算,得出了油膜厚度方程和油膜压力方程。通过对其摩擦系数试验研究,表明该结构能够使滑块在运动过程中得到良好的润滑,在一定程度上解决了摩擦副之间的摩擦、磨损问题。