A new set of materials has been developed that allow for the preparation of coatings with stimuli-responsive surfaces relying on acid-sensitive polymer brush layers. A functionalized methacrylate monomer, 5-(2-bromo-2-methylpropanoyloxy)-2,5-dimethylhexan-2-yl methacrylate, was synthesized and added to a photopolymerizable solution consisting of ethoxylated bisphenol A dimethacrylate, N-vinylpyrrolidone, 2-ethyl-2-(hydroxymethyl)-1,3-propanediol trimethacrylate, and 2,2-dimethoxy-2-phenylacetophenone. Thin films of this solution were spin-coated onto silicon wafers and cured. These substrates were placed into a reactor under atom transfer radical polymerization conditions which accomplished the growth of a polystyrene polymer brush layer from the photopolymer surface. Because of the acid-sensitive nature of the brush tether group, the brush layers could be selectively cleaved from the surface by treatment with a p-toluenesulfonic acid/dioxane solution. All surfaces were fully characterized before and after modification. The cleaved polymer from the brush layer was collected and characterized using gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR).

This paper describes photosensitive polyelectrolyte multilayers (PEMs), constructed using layer-by-layer (LbL) self-assembly, which contain polymers that comprise combinations of photocleavable methacrylate esters and photoinert cationic methacrylate esters. The solubility of these polymers in aqueous base depends upon irradiation with either ultraviolet or visible light. PEMs with dialkylaminocoumarin groups dissolve upon irradiation with visible light, while analogous films with nitrobenzyl ester-substituted polymers dissolve upon irradiation with UV light. Wavelength-selective release of fluorescent polymers as guests is demonstrated using this approach.

This paper describes controlled ring-opening metathesis polymerizations (ROMP) of norbornene derivatives that bear photoreactive o-nitrobenzyl ester (NBE) moieties. Termination reactions have frustrated previous reported attempts to execute controlled radical polymerizations with nitrobenzyl ester-containing acrylate derivatives. We therefore prepared new NBE-containing norbornene derivatives, and found that polymerization with Grubbs’s ruthenium carbene catalysts led to complete consumption of monomer in minutes to hours and yielded polymers with predictable molecular weights. We also demonstrate the preparation of NBE-containing block copolymers and show through UV irradiation of these polymers in solution and in thin film that the NBE moieties remain photoreactive.

Photoreactive polyelectrolyte multilayers (PEMs) that dissolve upon UV irradiation are described. Light-induced switching of the formal charge of a photoreactive polycation resulted in repulsive interlayer electrostatic forces, and caused the dissolution of PEM films. Combining both photoreactive and inert polycations in the same film yielded additional control over the light-induced change in film thickness.

An easy and novel approach to the synthesis of functionalized nanostructured polymeric particles is reported. The surfactant‐free emulsion polymerization of methyl methacrylate in the presence of the crosslinking reagent 2‐ethyl‐2‐(hydroxy methyl)‐1,3‐propanediol trimethacrylate was used to in situ crosslink colloid micelles to produce stable, crosslinked polymeric particles (diameter size ∼ 100–300 nm). A functionalized methacrylate monomer, 2‐methacryloxyethyl‐2′‐bromoisobutyrate, containing a dormant atom transfer radical polymerization (ATRP) living free‐radical initiator, which is termed an inimer (initiator/monomer), was added to the solution during the polymerization to functionalize the surface of the particles with ATRP initiator groups. The surface‐initiated ATRP of different monomers was then carried out to produce core–shell‐type polymeric nanostructures. This versatile technique can be easily employed for the design of a wide variety of polymeric shells surrounding a crosslinked core while keeping good control over the sizes of the nanostructures. The particles were characterized with scanning electron microscopy, transmission electron microscopy, optical microscopy, dynamic light scattering, and Raman spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1575–1584, 2007