Sökning: "solid state 13C NMR spectroscopy"

Visar resultat 1 - 5 av 20 avhandlingar innehållade orden solid state 13C NMR spectroscopy.

  1. 1. Investigating cellulose structure using solid-state NMR spectroscopy

    Författare :Alexander Idström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; CNC; crystallinity index; regenerated cellulose; 2D NMR; native cellulose; pulp; Solid-state NMR; ionic liquids; CP MAS 13C-NMR; hornification;

    Sammanfattning : Cellulose is the most abundant polymer in nature and it is an important constituent in most flowers, trees, and even some animals. Cellulose has an established use in many important products, such as textile fibers, paper and paperboard, and recently new applications have received increased attention. LÄS MER

  3. 2. Light-induced yellowing studied with ¹³C-enriched CW-DHP and solid state ¹³C NMR spectroscopy

    Författare :Jim Parkås; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; solid state; yellowing; picea abies; differentiation xylem; spruce; DHP; lignin; 13C NMR spectroscopy; 13C-enrichment;

    Sammanfattning : .... LÄS MER

  4. 3. Investigating structural changes of cellulose using NMR spectroscopy

    Författare :Alexander Idström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; crystallinity index; NCC; ionic liquids; CP MAS 13C-NMR; hornification; native cellulose; regenerated cellulose; NMR cryoporometry; pulp; Solid-state NMR;

    Sammanfattning : In this thesis solid-state NMR and NMR cryoporometry were used to gain information of the structure of cellulose. Measurements were conducted on both native and regenerated cellulose, exposed to a range of different treatments. LÄS MER

  5. 4. 13C-Enriched Dehydrogenation Polymers Used for Studying Light-Induced Yellowing of Lignocellulosic Materials

    Författare :Jim Parkås; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lignin model compounds; differentiating xylem; yellowing; Picea abies; 13C NMR spectroscopy; lignin; DHP; 13C-enrichment; solid state; spruce;

    Sammanfattning : This study deals with the use of selectively 13C-enriched dehydrogenation polymers (DHPs) as models of lignin in lignocellulosic materials for elucidating the reaction pathways involved in light-induced yellowing. Methods for the synthesis of coniferin, a precursor to lignin and DHP, selectively 13C-enriched in the aromatic ring (positions 1, 3, 4, and 5) have been developed. LÄS MER

  7. 5. Estimating molecular conformations by solid-state NMR spectroscopy

    Författare :Xiaolong Feng; R Griffin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

    Sammanfattning : Our understanding of structure-function relationships in biological systems demands new and more sophisticated methods for examining molecular structure. This thesis presents an effort of methodology development for molecular structure determination by solid-state NMR spectroscopy and applications to biological systems. LÄS MER