Abstract:2.3-Epoxypropyl methacrylate sorbed on porous glass was polymcrized by radical mechanism. The polymerization conditions were chosen so that the polymer obtained was linear or only very slightly crosslinked. The amount of the polymer on glass can be varied arbitrarily by diluting the polymerization mixture or by varying the amount of water on glass. The specific surface of the system decreases with increasing polymer content. With increasing specific surface of porous glass, i. e. with decreasing diameter of th… Show more
“…Therefore, we exploited chemical grafting from melt to fabricate the EHBP monolayer by using the known reaction between silanol and epoxy groups at elevated temperatures. − …”
We suggest a simple, one-step procedure to prepare a homogeneous functional polymer layer grafted
to a silicon oxide substrate. We demonstrate that robust and uniform nanoscale layers can be fabricated
from the functionalized hyperbranched polymer with dual nature of terminal branches: alkyl chains
combined with epoxy-functionalized chains. A branched chemical architecture with multiple epoxy groups
provides the grafting capability inducing surface functionality along with simultaneous hydrophobization
of the surface. We suggest the monolayer structure of these grafted films. These hyperbranched monolayers
are thicker than conventional alkyl-chain self-assembling monolayers (SAMs) and demonstrate elastic
properties typical for cross-linked polymer layers. The surface is composed of epoxy groups randomly
distributed within alkyl peripheral branches. Grafted hyperbranched polymer layers are homogeneous on
a nanoscale without signs of the microphase separation and heterogeneous domain surface structures
usually observed for two-component SAMs.
“…Therefore, we exploited chemical grafting from melt to fabricate the EHBP monolayer by using the known reaction between silanol and epoxy groups at elevated temperatures. − …”
We suggest a simple, one-step procedure to prepare a homogeneous functional polymer layer grafted
to a silicon oxide substrate. We demonstrate that robust and uniform nanoscale layers can be fabricated
from the functionalized hyperbranched polymer with dual nature of terminal branches: alkyl chains
combined with epoxy-functionalized chains. A branched chemical architecture with multiple epoxy groups
provides the grafting capability inducing surface functionality along with simultaneous hydrophobization
of the surface. We suggest the monolayer structure of these grafted films. These hyperbranched monolayers
are thicker than conventional alkyl-chain self-assembling monolayers (SAMs) and demonstrate elastic
properties typical for cross-linked polymer layers. The surface is composed of epoxy groups randomly
distributed within alkyl peripheral branches. Grafted hyperbranched polymer layers are homogeneous on
a nanoscale without signs of the microphase separation and heterogeneous domain surface structures
usually observed for two-component SAMs.
“…Obviously, the hydrophobic shell of predominantly alkyl branches prevented the formation of anchored macromolecules on a hydrophilic silicon surface. Therefore, we exploited chemical grafting from melt to fabricate the EHBP layer by using the known reaction between silanol groups and epoxy groups initiated at elevated temperatures (Scheme ). , The crucial point was to find a balance between the rate of grafting of epoxy-containing branches and the rate of dewetting caused by the interaction between hydrophobic branches and the hydrophilic silicon surface. We varied grafting conditions, such as concentration of the solution, thickness of the initial film, grafting time, and temperature, to avoid the dewetting phenomenon and ensure the formation of anchored and robust uniform layers.…”
We report the fabrication of a molecular surface coating from an epoxy-functionalized hyperbranched polyester functionalized by secondary epoxy groups. These groups were presented in the fraction of terminal branches of the hyperbranched shell with the ratio of epoxy-containing branches and alkyl branches of 1:2. We demonstrated that a uniform monolayer with the thickness of 4.5 nm could be fabricated by melt grafting of functionalized hyperbranched polymers to a bare silicon surface. Steric constraints imposed by the chemical attachment of alkyl and epoxydized branches to a single core prevented microphase separation of dissimilar segments and allowed the fabrication of uniform monolayers with surface exposure of the functional groups and high adhesion. An estimated 3-4 epoxy groups per molecule were located in the uppermost surface layer and provided residual functionality sufficient to graft another polymer layer. Grafted layers were extremely robust and sustain high compression and shear stresses while possessing high elasticity.
“…The data are obtained by imaging with tip radius 12.4 nm. Molecular weight distribution of HBP3 is based on the diameter distribution data (histogram) and GPC data (solid line) (b) Surface distribution of the elastic modulus and adhesive forces for the HBP3 nanoparticles on NHz SAM layer obtained with 64 x 64 probings within the I x 1 pm surface area (top). Correlation between height, young' s modulus and adhesion (bottom) Correlation of the height and elastic modulus for the HBP3 nanoparticles on NHz SAM layw obtained with 32 x 32 probings.…”
CHAPTER I.. INTRODUCTION 1 .1. General concept 1 .2. Morphology and properties of bulk hyperbranched polymer 1.3. Applications 1.4. Objectives and goals of the project CHAPTER 2. METHODOLOGY 2.1. Samples 2.L .l Hydroxyl-terminated hyperbranched polyester (HBP) 2 .l .2. Ep oxy-functional hyperbranched po lymer (EHBP) 2.1.3. Hydroxyl-terminated hyperbranched polymer (HP-0) and its substitutions with different percentage of CrzH:s branches 2.2Preparation of hyperbranched layers on solid surface 2.2.1 Substrates for hyperbranched molecules deposition 2.2.1.1 Bare silicon 2.2.L 2 Modification for bare silicon and tip 2.2.2 Deposition of hyperbranched polymer onto the substrates 2.
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