https://is.muni.cz/el/1431/podzim2006/C7780/um/Read/2711172/SAM_str_grwth_ProgSurfSci00_151.pdf

Structure and growth of self-assembling monolayers

Methods for Selective Modifications of Cyclodextrins.

Cyclodextrins (CDs), which possess a hydrophobic cavity, have a remarkable capacity to form inclusion complexes with various molecules through host-guest interactions It is well known that the usefulness of CDs is due to the combination of the inclusion properties and structural features of these molecules CDs are used extensively in separation science because CD-complexation phenomena offer a procedure of choice for separation of compounds and extraction processes, and provide a useful and versatile tool for protecting the environment The present review shows the advantages accruing from the use of adsorbents containing cyclodextrins, in particular in chromatographic separations and in waste water treatment The main goal of this review is to provide a summary of the information concerning the synthesis of materials containing CDs and to give a general overview of the different possible applications of CDs as sorbents in the field of separation techniques Recent and continuing interest in these adsorbents is evident from the number of papers that appear each year in the literature

Synthesis and applications of adsorbents containing cyclodextrins

This paper describes a general method to drastically improve the dispersity of oleic acid stabilized nanoparticles in aqueous solutions. We use oleic acid stabilized monodisperse nanoparticles of iron oxides and silver as model systems, and have modified the surface properties of these nanoparticles through the formation of an inclusion complex between surface-bound surfactant molecules and α-cyclodextrin (α-CD). After the modification, the nanoparticles of both iron oxide and Ag can transfer from hydrophobic solvents, such as hexane, to α-CD aqueous phase. The efficiency of the phase transfer to the aqueous solutions depends on the initial α-CD concentration. The α-CD/oleic acid complex stabilized nanoparticles can be stable for long periods of time in aqueous phase under ambient atmospheric conditions. Transmission electron microscopy (TEM), ultraviolet−visible (UV−vis) spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy, and colorimetric methods have been used in the characterization of these...

“Pulling” Nanoparticles into Water: Phase Transfer of Oleic Acid Stabilized Monodisperse Nanoparticles into Aqueous Solutions of α-Cyclodextrin

Electrical contacts between a metal probe and molecular monolayers have been characterized using conducting atomic force microscopy in an inert environment and in a voltage range that yields reversible current-voltage data. The current through alkanethiol monolayers depends on the contact force in a way that is accounted for by the change of chain-to-chain tunnelling with film thickness. The electronic decay constant, βN, was obtained from measurements as a function of chain length at constant force and bias, yielding βN = 0.8±0.2 per methylene over a ±3 V range. Current-voltage curves are difficult to reconcile with this almost constant value. Very different results are obtained when a gold tip contacts a 1,8-octanedithiol film. Notably, the current-voltage curves are often independent of contact force. Thus the contact may play a critical role both in the nature of charge transport and the shape of the current-voltage curve.

https://iopscience.iop.org/article/10.1088/0957-4484/13/1/302/pdf

Making electrical contacts to molecular monolayers

Several different cyclodextrinthiol derivatives have been immobilized on gold surfaces through a chemisorption process to form films which exhibit significantly different features. Three monothiolated cyclodextrin derivatives with different spacers between the cyclodextrin cavity and the thiol group and a mixture of multithiolated cyclodextrins were synthesized and characterized. Chemisorption of these compounds onto gold surfaces gave films which were investigated by Fourier transform infrared (FTIR) spectroscopy, time-of-flight mass spectrometry, contact angle measurements, plasmon surface polariton (PSP) spectroscopy, and cyclic voltammetry. It was found that the chemical structure of each cyclodextrin derivative had a strong influence on the molecular architecture in the resulting films, and in particular on the orientation of the cyclodextrin torus. Models were developed to describe the molecular arrangement in the films.

Controlled Orientation of Cyclodextrin Derivatives Immobilized on Gold Surfaces

In a previous paper we could demonstrate the immobilization of mono- and multithiolated cyclodextrins on gold surfaces and investigated the film properties. In this paper we follow the self-assembly processes in time by optical and physicochemical methods for those three monothiolated and a mixture of multithiolated cyclodextrin derivatives. The formation of cyclodextrin films on gold substrates was found to be a multistep process involving an activation energy.

Immobilization kinetics of cyclodextrins at gold surfaces

Selective ultrathin gold deposition by organometallic chemical vapor deposition onto organic self-assembled monolayers (SAMs)

Selective Gold Deposition via CVD onto Self-Assembled Organic Monolayers

We demonstrate the deposition of AlxOyHz onto hydroxy-terminated self-assembled monolayers. The layer structure is investigated by Fourier transform infrared (FTIR) spectroscopy, spontaneous desorption time-of-flight mass spectrometry, and surface plasmon spectroscopy. It is found that the organic self-assembled monolayer remains intact during deposition and the film thickness of the aluminum oxide and hydroxide films can be adjusted by varying the deposition time. The new aluminum hydroxide surface was used for a second self-assembly process with dodecanoic acid.

Peter Wohlfart

Papers

Controlled Orientation of Cyclodextrin Derivatives Immobilized on Gold Surfaces

Immobilization kinetics of cyclodextrins at gold surfaces

Selective ultrathin gold deposition by organometallic chemical vapor deposition onto organic self-assembled monolayers (SAMs)

Selective Gold Deposition via CVD onto Self-Assembled Organic Monolayers

MOCVD of Aluminum Oxide/Hydroxide onto Organic Self-Assembled Monolayers