Sökning: "hydroxide ion"

Visar resultat 1 - 5 av 43 avhandlingar innehållade orden hydroxide ion.

1. 1. Some aspects on TCF-bleachability of softwood alkaline pulps

   Författare :Karin Sjöström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bleachability; chlorine-free bleaching; softwoods; kraft pulps; alkaline sulfite pulps; oxygen; hydrogen peroxide; ozone; hydrogen sulfide ion; hydroxide ion; temperature; sodium ion.; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : The bleachability of softwood oxygen delignified pulps has been studied, i.e. the ease (requirement of bleaching chemicals) with which the pulps can be brightened to a target brightness in totally chlorine free (TCF) bleaching stages, including hydrogen peroxide, ozone and chelating agent stages. LÄS MER

3. 2. Some factors affecting the amount of residual phase lignin during kraft pulping

   Författare :Mikael E. Lindström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Deligniflcation; Residual phase lignin; Hydrogensulfide ion; Hydroxide ion; Polysulfides; Ionic strength; Temperature; Lignin; Kraftpulping; Selectivity; viscosity; Kappa number; chemical degradation; Disproportionation; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : The amount of lignin which needs to be removed according to the slow residual delignification phase in kraft pulping, i e residual phase lignin, has been studied as a function of the process conditions. The variebles studied were the concentrations of hydroxide ions, hydrogensulfide ions, sodium ions (ionic strength) and temperature. LÄS MER

4. 3. 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

5. 4. Polyhydroxyalkylations for alkali-stable cationic polymers as hydroxide exchange membranes

   Författare :Dong Pan; Centrum för analys och syntes; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quaternary ammoniums; aromatic polymers; chemical resistance; ion conductivity;

   Sammanfattning : To alleviate worldwide dependence on fossil fuels for energy production and considerably reduce CO2 emissions, green energy sources and sustainable energy solutions are in high demand. Fuel cells are environmental-friendly electrochemical devices which may use clean fuels, e.g., green hydrogen gas, to generate electricity. LÄS MER

7. 5. Elucidating Chemical and Electrochemical Side-Reaction Mechanisms in Li-ion Batteries

   Författare :Neeha Gogoi; Erik Berg; M. Rosa Palacín; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lithium-ion battery; solid electrolyte interphase; electrolyte additives; reaction mechanism; ethylene carbonate; vinylene carbonate; tris trimethylsilyl phosphate; surface enhanced Raman spectroscopy; Kemi med inriktning mot materialkemi; Chemistry with specialization in Materials Chemistry;

   Sammanfattning : Lithium-ion batteries constitute a leading technology that plays a major role in the transition towards sustainable transportation and power generation. The stability of modern batteries relies on a passivation layer formed on the negative electrode known as the solid electrolyte interphase (SEI). LÄS MER