Fabrication of spiropyran-containing thin film sensors used for the simultaneous identification of multiple metal ions.

In this article, a methacrylate-based spiropyran-containing copolymer was used as a colorimetric sensor to identify multiple metal ions simultaneously. Through UV-vis absorption spectroscopy, the relative binding affinity of merocyanine to each metal ion was investigated by displacement studies of a bound metal ion with a second metal ion of a higher binding affinity. We also show that because each metal ion gives rise to a distinct spectral response, partial least-squares discriminant analysis (PLS-DA) can be used to analyze the UV-vis absorbance spectra to identify the two metal ions that are present in solution at varying concentrations simply by dipping a coated polymer substrate into solution after irradiation.

Spectroscopic analysis of metal ion binding in spiropyran containing copolymer thin films.

In this article, we describe the synthesis and characterization of a series of spiropyran containing copolymers that were used as colorimetric sensors for a series of divalent metal ions. The composition of spiropyran contained in the polymer backbone was varied from 10-100 mol % to investigate the influence of free volume and sterics on the photochromic response. Fourier transform-infrared (FT-IR) spectroscopy was used to characterize the photoinduced conversion, as well as the merocyanine-metal ion (MC-M(2+)) interaction.

High density scaffolding of functional polymer brushes: surface initiated atom transfer radical polymerization of active esters.

In this Article, we describe a method for the polymerization of active esters based on N-hydroxysuccinimide 4-vinyl benzoate (NHS4VB) using surface initiated atom transfer radical polymerization (SI-ATRP). Poly(NHS4VB) brushes have high grafting density and a uniform and smooth morphology, and film thickness increases linearly with reaction time. Block copolymer brushes with 2-hydroxyethyl acrylate, tert-butyl acrylate, and styrene were synthesized from surface bound poly(NHS4VB) macroinitiators.