Interactions between Organized, Surface-Confined Monolayers and Vapor-Phase Probe Molecules. 12. Two New Methods for Surface-Immobilization and Functionalization of Chemically Sensitive Dendrimer Surfaces

Abstract

In this report we demonstrate two new methods for covalently linking dendrimers to surfaces. In the first method (method 1) a poly(iminopropane-1,3-diyl) dendrimer with 64 terminal-amine groups is first attached to a mixed mercaptoundecanoic acid (MUA)/mercaptopentane (MP) self-assembled monolayer (SAM), and then the unreacted terminal-amine groups of the dendrimer are converted to amide-linked functional groups by condensation with acid chlorides. The second method (method 2) involves bulk-phase coupling of suitable functional groups with the primary-amine-terminated dendrimer followed by reaction of the few unfunctionalized primary amines with the MUA component of the SAM to yield amide linkages. Five different dendrimer terminal groups are considered: primary amine, benzamide, 4-(trifluoromethyl)benzamide, butanamide, and triphenylacetamide. Fourier transform IR external reflection spectroscopy, ellipsometry, variable takeoff angle X-ray photoelectron spectroscopy, and surface acoustic wave device-based gravimetry reveal that these two approaches result in very different types of dendrimer monolayers. When the dendrimers are prepared by method 2, their surface concentration is lower than when the functionalization is done after attachment. However, the density of surface functionalities on each dendrimer is higher when dendrimer modification is performed prior to surface attachment. When the benzamido-terminated dendrimer surfaces are dosed with a variety of volatile organic compounds (VOCs), we find that the surface prepared by method 2 is more sensitive and that there is enhanced selectivity for the VOCs having π electrons. This result is interpreted in terms of π-stacking interactions with the aromatic groups on the dendrimer surfaces.

Synthesis and characterization of triazine‐based dendrimers and their application in metal ion adsorption

“…[24][25][26] Because of poly(ethylene glycol), increase water solubility of resulting dendrimers, have variety of potential applications in the fields of cell mimic systems, coatings, chemical sensors, hydrogel, and drug delivery. [27][28][29] From this point of view, we have initiated a program to clear the structure and properties of the synthesis of barbell-like dendritic triazine and functionalized with EDTA. The prepared functionalized dendrimers were used as a sorbent in series of adsorption experiments to investigate the behaviors of the synthetic dendrimers in removing metal ions from aqueous solutions.…”

Intercalation of dendrimers in the interlayer of hydrotalcite clay sheets

“…Owing to their structural uniformity, dendrimers provide a valuable model for correlating the macromolecular structure to the technological function [2][3][4][5]. Thus, dendrimers have a wide range of applications, including drug delivery [6], catalysis, and sensors [7][8] in high-technology fields. The organization of dendrimers in monolayers results in materials that can be applied as devices [7][8][9][10] and scaffolds for posterior elaborations [11][12][13][14][15][16][17].…”

“…Thus, dendrimers have a wide range of applications, including drug delivery [6], catalysis, and sensors [7][8] in high-technology fields. The organization of dendrimers in monolayers results in materials that can be applied as devices [7][8][9][10] and scaffolds for posterior elaborations [11][12][13][14][15][16][17]. Moreover, stratumous-layered composites of a dendrimer and a linear polymer can be prepared by linking terminal groups of a dendrimer to functional groups of a polymer [12,13,16,[18][19][20].…”

Preparation and study of cellulose acetate membranes modified with linear polymers covalently bonded to Starburst polyamidoamine dendrimers

“…15,16 Because of the unique chemical and structural properties of dendrimers, a number of potential applications have been proposed, some of which include the design and preparation of chemical sensors, [17][18][19] the dendritic encapsulation of transition-metal ions, [20][21][22][23] the controlled release of small compounds, 24 and their use in membrane chemistry, 25,26 among many others. 27,28 In the area of membrane construction with dendrimers, Crooks and coworkers [29][30][31] have developed novel polymeric composite films formed from multilayers of amine-terminated polyamidoamine (PAMAM) dendrimers and poly(maleic anhydride)-c-(methyl vinyl ether) (Gantrez) grafted onto Aucoated Si wafers.…”