Search for dissertations about: "cellulose II"

Showing result 1 - 5 of 85 swedish dissertations containing the words cellulose II.

2. 1. Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps

   Author : Heléne Almlöf Ambjörnsson; Ulf Germgård; Thomas Nilsson; Storker Moe; Karlstads universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alkali; carboxymethyl cellulose; cellulose I; cellulose II; cellulose dissolution; degree of substitution; enzymatic treatment; filterability; gel formation; mercerization; multivariate analytical methods; NIR FT Raman spectroscopy; sodium hydroxide; zink oxide; Chemical Engineering; Kemiteknik;

   Abstract : This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose. READ MORE

4. 2. Experimental study of alkalinisation of cellulose in industrial relevant conditions

   Author : Diana Carolina Reyes Forsberg; Ola Sundman; Bertil Eliasson; Ulf Germgård; Umeå universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Mercerisation; Alkalinisation; Cellulose I; Cellulose II; Alkali cellulose; Viscose; Cellulose ether; Carboxymethylcellulose; Sodium glycolate; Sodium diglycolate; Raman spectroscopy;

   Abstract : Mercerisation of cellulose pulp with a solution of NaOH is the first step of manufacturing cellulose-based value-added products, e.g. viscose fibres and cellulose ethers. During this process, cellulose transforms into a swollen crystalline structure, alkali cellulose (Na-Cell). READ MORE

5. 3. Tailoring Cellulose Nanofibrils for Advanced Materials

   Author : Núria Butchosa Robles; Qi Zhou; Kristiina Oksman; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose nanofibrils; bacterial cellulose; surface modification; carboxymethyl cellulose; polyethylene glycol; chitin nanocrystals; bactericidal activity; nanofibrils orientation; water redispersability; mechanical properties; dye removal; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : Cellulose nanofibrils (CNFs) are nanoscale fibers of high aspect ratio that can be isolated from a wide variety of cellulosic sources, including wood and bacterial cellulose. With high strength despite of their low density, CNFs are a promising renewable building block for the preparation of nanostructured materials and composites. READ MORE

6. 4. Structural changes during cellulose composite processing

   Author : Helena Halonen; Monica Ek; Tommy Iversen; Derek D. Gray; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; CP MAS 13C NMR; cellulose; fibril aggregation; biocomposite; compression moulding; supramolecular structure;

   Abstract : Two approaches for creating a new all-cellulose composite material have been studied: the biosynthesis of compartmentalised bacterial cellulose fibril aggregates and the compression moulding of commercial chemical wood pulps processed with only water. The objective was to study the structural changes during processing and the complexity of relating the mechanical properties of the final biocomposites to the nanoscale structure was highlighted. READ MORE

7. 5. Manufacturing and Characterization of Cellulose Nanofibers

   Author : Carl Moser; Mikael Lindström; Gunnar Henriksson; Kristin Syverud; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose; Nanofibers; Characterization; Homogenization; Endoglucanase; TEMPO; Specific surface area; Atomic force microscopy; Cellulosa; Nanofibrer; Karakterisering; Homogenisering; Endoglukanas; TEMPO; Specifik ytarea; Atomkraftmikroskopi; Fiber- och polymervetenskap; Fibre and Polymer Science;

   Abstract : The usage of wood has been a dominant driving force during the evolution of the human species. It allowed us to cook food, build tools, put roofs over our head and explore the world. The fibers making up the tree has been the most important way to store and transmit knowledge in the form of paper for centuries. READ MORE