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: 6159105
• 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: 1999
• 资助国家: 美国
• 起止时间: 1999-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6159105
• 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.

提出了有机硫化合物在二氧化硅表面粘附的研究。这项工作定义了一种以前未知的将碳氢化合物结合到二氧化硅表面的模式。接枝在表面上的分子的化学反应在表面科学中引起了越来越多的兴趣。这些系统以红外传输和固态核磁共振为特征，与生物粘附直接相关——粘附在膜上的细菌或粘附在生物植入物上的白细胞的物理和化学相互作用。有四个主要目标： 1. 二氧化硅 (100012) 上的新表面反应。我们将在高真空中将有机硫化合物与加热至 1000°C 的二氧化硅表面进行反应。例如，硫醇产生含有S-Si键的硫代硅氧烷膜。 2.二氧化硅(1000)上双功能分子的表面接枝。双官能分子，含有与二氧化硅（1000）反应的有机硫头基和暴露在表面的末端官能团将被接枝。第二个官能团必须不与二氧化硅（1000）反应，或者受到化学保护以防止发生此类反应。例如，在双功能分子（例如卤代烷硫醇 Cl-(CH2)nSH）中，S 和 Cl 都可能与表面硅氧烷相互作用。三官能半胱氨酸可以通过其SH基团通过酯化保护羧酸盐和通过烷基化保护胺而被吸收。 3.原位反应。目标是制备无法直接通过吸收双功能分子制备的表面功能。上述2中提到的保护基团的脱烷基和水解将是第一个实验。另一项研究是醛封端的硫硅氧烷薄膜的制备；吸附物前体 C=O (CH2)nSH 在合成上是无法获得的。该公司可能会弱协调/粘附金属。 4. 吸附物与改性表面的相互作用。对界面分子环境的研究揭示了影响表面-吸附物相互作用的基本因素。我们将系统地改变烷基链长度和链末端，以实现表面吸收特性的空间和化学控制。这些影响将通过受控大气环境（例如，大气环境）的光谱研究来探讨。可逆吡啶配位。