Positron Lifetime Reveals the Nano Level Packing in Complex Polysaccharide-Rich Hydrolysate Matrixes
2012 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 84, no 8, 3676-3681 p.Article in journal (Refereed) Published
Positron annihilation lifetime spectroscopy (PALS) was used to quantify the free volume and molecular packing in hydrolysate and hemicellulose-based barriers films, derived from process streams during wood processing operations. These hydrolysate films, comprising a fair share of lignin coexisting with poly- and oligo-saccharides, have very low but variable oxygen permeability but differ among themselves with respect to barrier performance as well as molecular weight, degree of branching, and monosaccharide residue main chain composition. From PALS measurements on hydrolysates, the free volume hole radius (r(h)), radius distributions (n(r(h))), volume-weighted hole sizes (<v(h)>(v)), and hole volume distributions (g(v(h))) were calculated showing that the hydrolysate matrixes are very densely packed with small holes. The results show a clear relationship between hydrolysate molecular architecture and composition, the nanolevel molecular packing, and the ability of suppressing the diffusion of oxygen through the film.
Place, publisher, year, edition, pages
2012. Vol. 84, no 8, 3676-3681 p.
Barrier performance, Degree of branching, Fair share, Hole radius, Hole size, Main chains, Molecular architecture, Molecular packings, Oxygen permeability, Positron annihilation lifetime spectroscopy, Positron lifetime, Process streams, Small Hole, Volume distributions, Wood processing
IdentifiersURN: urn:nbn:se:kth:diva-95094DOI: 10.1021/ac300152gISI: 000302838500029ScopusID: 2-s2.0-84859887431OAI: oai:DiVA.org:kth-95094DiVA: diva2:526875
QC 201205152012-05-152012-05-142013-05-15Bibliographically approved