Cross-linked poly-vinyl polymers versus polyureas as designed supports for catalytically active M 0 nanoclusters : Part I. Nanometer scale structure of the polyurea support EnCat™ 40

Abstract

The cross-linked polymer EnCat™ 40 (polyurea) is investigated on the micro-(ESEM) and nanometer scale (ISEC, ESR, 13C CP MAS NMR) both in the dry (ESEM, 13C CP MAS NMR) and in the swollen state (ISEC, ESR, 13C CP MAS NMR). After swelling with THF or DMF, nanoporous domains featured by ca. 1.2 nm pores are clearly detected with ISEC. ESR analysis based on the evaluation of the rotational mobility of a suitable spin probe dissolved in THF, DMF, MeOH and PhCH 3 as swelling media, does qualitatively confirm the presence of nanoporosity also in MeOH- and PhCH 3-swollen EnCat™ 40. Our manifold analysis reveals the lack of any detectable nanoporosity in water.