Suspension Photopolymerization of Methyl Methacrylate and ATRP Grafting of Thermo‐Responsive Polymers Using a Perylediimide Derivative Photoinitiator

Abstract The first aim of this study is to develop a photo‐ATRP process using methyl methacrylate (MMA) by employing a novel perylenediimide derivative (PDI) as photoinitiator. The analysis of the MMA photopolymerization process kinetics is performed in solution and in bulk, demonstrating control over the reaction progress even if the polymerizations display a slow initiation step. The photo‐ATRP process for MMA in suspension is also developed and the obtained PMMA particles are further used to reinitiate the ATRP polymerization of thermoresponsive polymers (different molecular weights poly(ethylene glycol) methyl ether methacrylate and poly(N‐isopropylacrylamide)) (PNIPAM) in solution and surface‐initiated processes. The synthesized polymers by surface‐initiated process display a bimodal molecular weight distribution with a clear modification of the signal areas ratio depending on the grafted monomer and on the reaction conditions. The grafting process can take place on the surface of the polymer particles (Mn2), or it can also involve polymer chains located further at the interior of the polymer particles (Mn1). The lower critical solution temperature (LCST) transition is demonstrated for the PNIPAM functionalized polymer particles

Bisphenol A Adsorption on Silica Particles Modified with Beta-Cyclodextrins

This study presents the synthesis of silica particles bearing two beta-cyclodextrin (BCD) (beta-cyclodextrin-BCD-OH and diamino butane monosubstituted beta-cyclodextrin-BCD-NH2). The successful synthesis of the BCD-modified silica was confirmed by FT-IR and TGA. Using contact angle measurements, BET analysis and SEM characterization, a possible formation mechanism for the generation of silica particles bearing BCD derivatives on their surface was highlighted. The obtained modified silica displayed the capacity to remove bisphenol A (BPA) from wastewater due to the presence of the BCD moieties on the surface of the silica. The kinetic analysis showed that the adsorption reached equilibrium after 180 min for both materials with qe values of 107 mg BPA/g for SiO2-BCD-OH and 112 mg BPA/g for SiO2-BCD-NH2. The process followed Ho’s pseudo-second-order adsorption model sustaining the presence of adsorption sites with different activities. The fitting of the Freundlich isotherm model on the experimental results was also evaluated, confirming the BCD influence on the materials’ adsorption properties

Diseño y desarrollo de una aplicación para la formación de neurofisiólogos en la identificación de señales MER en cirugía de estimulación cerebral profunda

La estimulación cerebral profunda (ECP) es una técnica quirúrgica por la que se palían los síntomas de enfermedades neurológicas tales como la Enfermedad de Parkinson (EP). En la ECP, se lleva a cabo una inserción de microelectrodos (MER) cerebrales que registran la actividad neuronal, así como emiten pequeñas descargas para mejorar los síntomas del paciente. Uno de los retos formativos para los neurofisiólogos consiste en la identificación de la zona cerebral en la que se está implantando el electrodo. Dicha formación se suele llevar a cabo en el quirófano, con pacientes reales. En este trabajo se ha desarrollado una aplicación que permite entrenar la identificación de señales MER de forma offline a partir de registros pregrabados. El usuario debe reconocer las zonas cerebrales involucradas en función de la información visual y/o auditiva de la señal. La aplicación se validará con especialistas neurofisiólogos del Hospital Universitario La Paz (Madrid). Gracias a la aplicación especialistas médicos podrán comprobar si son capaces o no de reconocer las distintas áreas cerebrales involucradas para finalizar con éxito futuras intervenciones