Microwave assisted formation of monoreactive perfluoroalkylsilane-based self-assembled monolayers

Abstract

We demonstrate the use of microwave radiation as a tool to accelerate the formation of perfluoroalkylsilane based self-assembled monolayers (SAMs) on silicon oxide surfaces. Surface coverage of these SAMs of monoreactive perfluoroalkylsilanes increased in proportion to the duration over which the solutions were heated by microwave radiation.

Rapid Covalent Modification of Silicon Oxide Surfaces through Microwave-Assisted Reactions with Alcohols

“…Soxhlet extraction of the monolayer-modified SiO x surfaces was performed to evaluate the extent to which these surfaces were covalently modified with the aliphatic alcohols. The extraction process should remove 1-octanol that is only weakly interacting with the substrates. , The relative change in WCA following extraction continued to decrease with an increasing duration of microwave radiation (Figure ). In other words, the hydrophobicity of the monolayer-covered surfaces remained consistent after prolonged extraction with hot toluene when the monolayers were prepared with a longer (e.g., 30 min) duration of microwave treatment.…”

“…[37][38] Recently, processes have been demonstrated that utilize microwave radiation to assist the formation of monolayers of alkanethiolates on gold, 39 alkenes on silicon carbide, 40 and alkylsilanes on glass slides, 41 cotton fabrics, 42 and silicon chips with thermally grown oxides. 43 The use of microwave radiation has been demonstrated for the reaction of alcohols on hydrogen terminated silicon [44][45] but has not been extended to the condensation reactions between alcohols and silicon oxides.…”

“…Microwave radiation is an attractive alternative means of providing the required thermal energy for the formation SAMs from alcohols. Microwaves can heat a reaction faster and more effectively than convective heating, and microwaves have been widely utilized to initiate reactions in organic synthesis − and materials science. , Recently, processes have been demonstrated that utilize microwave radiation to assist the formation of monolayers of alkanethiolates on gold, alkenes on silicon carbide, and alkylsilanes on glass slides, cotton fabrics, and silicon chips with thermally grown oxides . The use of microwave radiation has been demonstrated for the reaction of alcohols on hydrogen-terminated silicon , but has not been extended to the condensation reactions between alcohols and silicon oxides.…”

Tuning Oleophobicity of Silicon Oxide Surfaces with Mixed Monolayers of Aliphatic and Fluorinated Alcohols

“…Silicon oxide surfaces with a fine-tuned oleophobicity were prepared using microwave-assisted reactions with mixtures of fluorinated and aliphatic alcohols. Fluorinated or partially fluorinated surfaces have been previously investigated for their ability to tailor the physical properties of surfaces, such as friction and wettability, electronic properties, or resistance to biomolecules, − for usage in applications that include antiwetting, oil–water separation, electronic devices, − and biomaterials. − In particular, silicon oxide surfaces modified with fluorocarbon or hydrocarbon chains have been widely pursued in fields requiring a fine control over interface wetting, − electronics, − and separation science. − In order to functionalize silicon oxides with fluorocarbons or hydrocarbons, silane-based compounds have been widely utilized to modify the properties these surfaces through the formation of molecular-scale coatings, commonly referred to as self-assembled monolayers (SAMs). ,− Challenges in the formation of silane-based monolayers include the reactivity of silanes with water, their sensitivity to intermolecular polymerization, and tendency to form multilayers. − These challenges ultimately limit the control over composition of the monolayers, especially when mixed monolayers are required for tailoring the properties of surfaces. In contrast, alcohol-based reagents forego many of these challenges due to their minimal reactivity with water.…”

Photobiocidal-triboelectric nanolayer coating of photosensitizer/silica-alumina for reusable and visible-light-driven antibacterial/antiviral air filters

“…The C 1s spectra also showed that CF 3 and CF 2 bonds were dominant on the SAS layer ( Fig. 2 k) [33] . Meanwhile, the C–O bond of GPTMS, a major component of the SAS matrix, was homogeneously distributed inside the coating layer.…”