Asphaltene adsorption onto self-assembled monolayers of mixed aromatic and aliphatic trichlorosilanes.
نویسندگان
چکیده
The adsorption of asphaltenes onto flat solid surfaces modified with mixed self-assembled monolayers (SAMs) of aliphatic and aromatic trichlorosilanes with varying wettabilities, aromaticities, and thicknesses is tested. The mixed SAMs are characterized by means of contact angle to assess hydrophobicity and molecular and chemical uniformity, spectroscopic ellipsometry to measure the thickness of the films, and near edge X-ray absorption fine structure (NEXAFS) spectroscopy to assess chemical and molecular composition. The molecular characteristics of the adsorbed asphaltene layer and the extent of asphaltene adsorption are determined using NEXAFS and spectroscopic ellipsometry, respectively. The SAMs are formed by depositing phenyl-, phenethyl-, butyl-, and octadecyl- trichlorosilanes from toluene solutions onto silica-coated substrates; the chemical composition and the wettability of the SAM surface is tuned systematically by varying the trichlorosilane composition in the deposition solutions. The adsorption of asphaltenes on the substrates does not correlate strongly with the SAM chemical composition. Instead, the extent of asphaltene adsorption decreases with increasing SAM thickness. This observation suggests that the leading interaction governing the adsorption of asphaltenes is their interaction with the polar silica substrate and that the chemical composition of the SAM is of secondary importance.
منابع مشابه
Study of the packing density and molecular orientation of bimolecular self-assembled monolayers of aromatic and aliphatic organosilanes on silica.
Bimolecular self-assembled monolayers (SAMs) of aromatic and aliphatic chlorosilanes were self-assembled onto silica, and their characteristics were established by contact angle measurement, near-edge X-ray absorption fine structure spectroscopy, and Fourier transform infrared spectroscopy. Three aromatic constituents (phenyltrichlorosilane, benzyltrichlorosilane, and phenethyltrichlorosilane) ...
متن کاملStudy on the barrier properties and interfacial properties of self-assembled monolayers (SAMs) of aliphatic, aromatic and alkoxycyanobiphenyl thiols on gold surface prepared using a lyotropic liquid crystalline phase as an adsorbing medium
متن کامل
A Study on the Adsorption and Catalytic Oxidation of Asphaltene onto Nanoparticles
The use of nanoparticles, including metal oxide surfaces, as asphaltene adsorbents is a potential method of removing and/or upgrading asphaltenes. The adsorption of two asphaltene types, extracted from two types of Iranian crude oil, onto nanoparticles (TiO2, SiO2, and Al2O3) are assessed and the thermal behavior of the adsorbed asphaltenes is examined under an oxidizing atmosphere through ther...
متن کاملThe correlation between osteopontin adsorption and cell adhesion to mixed self-assembled monolayers of varying charges and wettability.
Osteopontin (OPN) is a key mediator of cell interactions with biomaterials. However, few studies have been dedicated to studying cell adhesion on OPN-adsorbed substrates with controlled charge and wettability. Here, amino-carboxyl (NH2/COOH) and hydroxyl-methyl (OH/CH3) mixed self-assembled monolayers (SAMs) of varying charges and wettability, respectively, were used as controllable model surfa...
متن کاملSelf-Assembled Monolayers of Symmetrical and Mixed Alkyl Fluoroalkyl Disulfides on Gold. 1. Synthesis of Disulfides and Investigation of Monolayer Properties
The synthesis of a variety of symmetrical bis(alkyl) and bis(fluoroalkyl) disulfides as well asmixed alkyl fluoroalkyl disulfides containing ester or amide groups is described. Self-assembled monolayers of these compounds on gold formed by spontaneous adsorption from solution are studied by contact angle measurementsandpolarizedgrazing incidenceFourier transforminfraredspectroscopy (FTIR). The ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Langmuir : the ACS journal of surfaces and colloids
دوره 25 11 شماره
صفحات -
تاریخ انتشار 2009