Hydrolytic and Thermal Stability of Organic Mono layers on Various Inorganic Substrates
Hydrolytic and Thermal Stability of Organic Mono layers on Various Inorganic Substrates
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DOI：
10.1021/la500533f
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发表时间：
2014-05-27
期刊：
影响因子：
3.9
通讯作者：
Zuilhof, Han
中科院分区：
文献类型：
--
作者：
Bhairamadgi, Nagendra S.;Pujari, Sidharam P.;Zuilhof, Han
对比研究了24种不同单层膜在Si（111）、Si（100）、SiC、SiN、SiO2、CrN、ITO、PAO、Au和不锈钢表面的水解和热稳定性。这些表面被适当的有机化合物修饰，这些有机化合物具有恒定的烷基链长（C-18），但具有不同的表面活性基团，如1-十八烯、1-十八环、1-十八烷基三氯硅烷、1-十八烷基硫醇、1-十八烷基胺和1-十八烷基膦酸。在室温下连续流动的水介质中，分别在酸性（pH 3）、碱性（pH 11）、磷酸盐缓冲盐水（PBS）和去离子水（中性条件）中，系统地研究了所获得的单分子膜的水解稳定性，时间分别为1天、7天和30天，得到了水解稳定性的1152个数据点。通过静态接触角测量和x射线光电子能谱（XPS）监测其水解稳定性。在酸性和中性条件下，Si（I I 1）、Si（100）和SiC上共价结合的炔单分子膜是最稳定的单分子膜。此外，利用XPS研究了14种不同单层膜在高温（25-600℃）下的热稳定性。与水解稳定性类似，Si（111）、Si（100）和SiC上的共价键结合的炔和烯单分子膜在温度高于260℃时开始降解，而在氧化物表面（例如PAO）上的膦酸盐单分子膜甚至显示出高达500℃的热稳定性。
A comparative study is presented of the hydrolytic and thermal stability of 24 different kinds of monolayers on Si(111), Si(100), SiC, SiN, SiO2 CrN, ITO, PAO, Au, and stainless steel surfaces. These surfaces were modified utilizing appropriate organic compounds having a constant alkyl chain length (C-18), but with different surface-reactive groups, such as 1-octadecene, 1-octadecyne, I-octadecyltrichlorosilane, I-octadecanethiol, I-octadecylamine and 1-octadecylphosphonic acid. The hydrolytic stability of obtained monolayers was systematically investigated in triplicate in constantly flowing aqueous media at room temperature in acidic (pH 3), basic (pH 11), phosphate buffer saline (PBS) and deionized water (neutral conditions), for a period of 1 day, 7 days, and 30 days, yielding 1152 data points for the hydrolytic stability. The hydrolytic stability was monitored by static contact angle measurements and X-ray photoelectron spectroscopy (XPS). The covalently bound alkyne monolayers on Si( I I 1), Si(100), and SiC were shown to be among the most stable monolayers under acidic and neutral conditions. Additionally, the thermal stability of 14 different monolayers was studied in vacuum using XPS at elevated temperatures (25-600 degrees C). Similar to the hydrolytic stability, the covalently bound both alkyne and alkene monolayers on Si(111), Si(100) and SiC started to degrade from temperatures above 260 degrees C, whereas on oxide surfaces (e.g., PAO) phosphonate monolayers even displayed thermal stability up to similar to 500 degrees C.