Sökning: "Hydroxide"

Visar resultat 1 - 5 av 171 avhandlingar innehållade ordet Hydroxide.

1. 1. Cellulose solutions in aqueous hydroxide bases

   Författare :Beatrice Swensson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose; dissolution; NaOH; aqueous; solvent; quaternary ammonium hydroxide;

   Sammanfattning : Cellulose is a renewable and widely available carbohydrate polymer whose utility for mankind only increases as we move towards a circular bioeconomy. Unlike most plastics or metals, it cannot be melted, and therefore, solution processing is important. LÄS MER

3. 2. Cellulose in quaternary ammonium hydroxide solutions

   Författare :Shirin Naserifar; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; quaternary ammonium hydroxides; cellulose; N; N-dimethylmorpholinium hydroxide; Triton B; NaOH; dissolution; TMAH; etherification;

   Sammanfattning : An ever-increasing demand to shift away from fossil-based feedstock towards renewable resources has led to more use of bio-based materials. Cellulose being the most abundant biopolymer on Earth has received a considerable attention with a wide range of applications (in textile fibers, films, membranes, etc. LÄS MER

4. 3. Towards alkali-stable polymers and hydroxide exchange membranes functionalized with alicyclic quaternary ammonium cations

   Författare :Thanh Huong Pham; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydroxide exchange membrane; fuel cell; alicyclic quaternary ammonium; alkali-stable; high hydroxide conductivity; structure-property relationship;

   Sammanfattning : In the current work, cationic polymers functionalized with N-alicyclic quaternary ammonium (QA) cations were synthesized and characterized as potential hydroxide exchange membranes (HEMs) for application in fuel cells. Three different polymers, namely poly(arylene ether sulfone), spiro-ionene and poly(arylene alkylene), were explored as polymer backbones for the HEMs. LÄS MER

5. 4. On the Interrelation Between Kraft Cooking Conditions and Pulp Composition

   Författare :Catrin Gustavsson; Mikael E. Lindström; Jorge Colodette; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Kraft pulping; Residual phase lignin; Hydroxide; Hydrogen sulphide ion; Ionic strength; Temperature; Bleachability; Hexenuronic acid; Carbohydrates; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : In the early 1990’s, a lot of work was focused on extending the kraft cook to a low lignin content (low kappa number). The driving force was the need to further reduce the environmental impact of the bleaching, as less delignification work would be needed there. LÄS MER

7. 5. Dissolution of cellulose in aqueous hydroxide base solvents

   Författare :Beatrice Swensson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; aqueous; NaOH; quaternary ammonium hydroxide; solvent; cellulose; dissolution;

   Sammanfattning : As we move towards a circular bioeconomy, new and advanced materials based on cellulose are constantly developed. Unlike most plastics or metals, cellulose cannot be melted, and therefore dissolution is an important tool for processing of cellulose but also for analytical purposes. LÄS MER