MODIFICATION OF SURFACE REACTIVITIES ON SILICA (1000) AS MODELS OF BIOADHESION

作为生物粘附模型的二氧化硅 (1000) 表面反应性的修饰

• 批准号: 6325824
• 负责人: EARL L SMITH
• 金额: $ 4.04万
• 依托单位: UNIVERSITY OF TEXAS EL PASO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6325824
• 关键词: X ray crystallography; adhesions; biomaterial interface interaction; chemical models; chemical reaction; gas chromatography mass spectrometry; infrared spectrometry; membrane fusion; nuclear magnetic resonance spectroscopy; organic chemicals; silicates; sulfur compounds; thioether; thiols

A study of the adhesion of organosulfur compounds at the surface of silica is proposed. This work defines a previously unknown mode of binding hydrocarbon to the surface of silica. Chemical reactions of molecules grafted on surfaces are of growing interest in surface science; these systems, characterized by IR transmission and solid state NMR, have direct relevance to bioadhesion--the physical and chemical interactions of bacteria adhering to membrane, or white blood cells adhering to bioimplants. There are four major targets: 1. New surface reactions on Silica (100012). We will react organosulfur compounds with the surface of silica heated to 1000C in high vacuum. For example, a thiol gives a thiosiloxane film containing the S-Si bond. 2.Surface Grafting of Bifunctional Molecules on Silica (1000). Bifunctional molecules, containing the organosulfur head group to react with the silica (1000) and a terminal functional group exposed at the surface will be grafted. The second functionality must either not react with the silica (1000) or be chemically protected from such reaction. For example, in a bifunctional molecule such as a halogenated alkanethiol, Cl-(CH2)nSH, both the S and the Cl could potentially interact with surface siloxanes. Trifunctional cysteine could be absorbed exclusive through its SH group by protecting the carboxylate through esterification and the amine through alkylation. 3. In-situ reactions. The goal is to prepare surface functionalities which could not be prepared directly from absorption of bifunctional molecules. Dealkylation and hydrolysis of protected groups referred to in 2 above will be the first experiments. Another examine would be preparation of an aldehyde terminated thiosiloxane film; the adsorbate precursor C=O (CH2)nSH is synthetically inaccessible. This firm may weakly coordinate /adhere metals. 4. Adsorbate-Interactions with the Modified Surfaces. Studies of the molecular environment at the interface reveal the fundamental factors affecting surface-adsorbate interactions. We will vary systematically the alkyl chain length and the chain terminus to effect steric and chemical control of the surface's absorption properties. These effects will be probed with spectroscopic studies of controlled atmosphere environments such as e.g. reversible pyridine coordination.

本文研究了有机硫化合物在二氧化硅表面的粘附性。这项工作定义了一个以前未知的模式结合碳氢化合物的表面的二氧化硅。接枝在表面上的分子的化学反应在表面科学中越来越受到关注;这些系统的特征在于IR透射和固态NMR，与生物粘附-粘附到膜上的细菌或粘附到生物植入物上的白色血细胞的物理和化学相互作用直接相关。有四个主要目标：1。二氧化硅上的新表面反应（100012）。我们将在高真空中加热到1000 ℃的二氧化硅表面与有机硫化合物反应。例如，硫醇产生含有S-Si键的硫代硅氧烷膜。2.双功能分子在二氧化硅（1000）上的表面接枝。将接枝含有与二氧化硅（1000）反应的有机硫头部基团和暴露在表面处的末端官能团的双官能分子。第二官能度必须不与二氧化硅（1000）反应或被化学保护免于这种反应。例如，在双官能分子中，如卤代烷乙氧基化物，Cl-（CH2）nSH，S和Cl都可能与表面硅氧烷相互作用。通过酯化保护羧酸酯和烷基化保护胺，三官能半胱氨酸可以通过其SH基团被单独吸收。3.原位反应。目标是制备不能直接从双功能分子的吸收制备的表面官能团。上述2中提到的被保护基团的脱烷基化和水解将是第一个实验。另一项研究将是制备醛封端的硫代硅氧烷膜;吸附物前体C = O（CH2）nSH是合成不可接近的。该公司可能会弱配位/粘附金属。4.与改性表面的吸附相互作用。界面处的分子环境的研究揭示了影响表面-吸附质相互作用的基本因素。我们将系统地改变烷基链的长度和链末端，以实现对表面吸收特性的空间和化学控制。这些影响将探测与光谱研究的受控气氛环境，如可逆吡啶配位。