Sodium hydroxide can cause cellulose to swell and can even dissolve cellulose in a narrow range of the phase diagram. It was found that for cellulose with low to moderate degree of polymerization, the maximal solubility occurs with 8~10% soda solution. In recent years, researchers found that sodium hydroxide with urea at cold temperature can dissolve cellulose better than sodium hydroxide alone. However, the lack of sufficient understanding of the NaOH and NaOH/urea dissolution process significantly constrains its applications. In order to fully understand the cellulose dissolution in alkali system, there are several aspects of problems that need to be addressed. Our focus in this study is in the interaction of cellulose with alkali solution at low temperatures, the improvement of its solubility, and the effect of hemicellulose and lignin.

This thesis examines how the rheological properties change depending on the composition of hyaluronan, HA and sodium hydroxide, NaOH. This was performed to see if there was any relationship between the rheological properties of a sample depending on different compositions of HA and NaOH. Moreover, the fluidity of the samples was studied by investigating . Five concentrations of HA (11, 18, 20, 25, 33 wt%) were investigated with six concentrations of NaOH (0, 1, 2, 4, 6, 8 wt%). Rheology was used to determine rheological properties of the composition and the rheometric data was obtained from three different measurements: time sweep, frequency sweep and amplitude sweep. G', G'' andwere investigated but no clear correlation was found. However, some patterns were detected for frequency sweep and amplitude sweep. The graphs generally followed the same shape and the compositions with 11% HA generally had the lowest G' and G'' values. Additionally, the majority of the samples, that could be measured, could be defined as fluids, due to  being higher than 1.

Corn distiller’s dried grains with solubles (DDGS) is mostly marketed as a livestock feed due to its high protein content of 30%. Recently, the proteins in DDGS have shown potential to act as binding agents along with melamine-urea-formaldehyde resin. However, it is unknown if DDGS can be chemically functionalized as a natural binder to replace synthetic resin in particleboard. In this study, several formulations were tested using various concentrations of acetic acid and sodium hydroxide treatments with combinations of temperature, DDGS concentrations, particle sizes, and wax. FTIR results indicated that DDGS proteins were decoupled through acid or alkali treatments, and acid treated DDGS in particleboards displayed higher improvements in internal bond strength as well as the moisture resistance of the particleboards. These results suggest that acid or alkali treated DDGS has potential to act as a natural binder for manufacturing medium-density particleboard.

Sprayer hygiene and concerns of off-target injury from auxin herbicides have increased in recent years. New auxin tolerant crops have broadened the use patterns of these herbicides. Therefore, experiments were conducted across two locations in Mississippi in 2016, 2017, and 2018 to evaluate sprayer cleanout procedures to aid in dicamba removal. Standard sprayer cleanout consisted of a triple rinse of 10% tank volume, with either a tank cleaner or ammonia added in the second rinse. Samples collected in each rinse step for all treatments were applied to actively growing soybean and dicamba concentration quantified with HPLC. Experiments were conducted to determine if various tank cleaners and ammonia produce visual injury when applied to actively growing soybean and cotton alone and in conjunction with glyphosate. No tank cleaner caused visual injury nor affected plant heights or yield. Furthermore, experiments were conducted to evaluate tank cleaner effectiveness to remove dicamba utilizing the standard cleanout procedure, with increased rinse volumes, sequence of water and tank cleaner rinses, and cleanout effectiveness following durations of idle time from application to cleanout. No tank cleaner provided greater dicamba removal, with all cleaners performing the same as cleanouts utilizing water alone. Increasing rinse volumes did not positively affect dicamba removal compared to 10% rinse volumes. Multiple rinse steps utilizing a tank cleaner or altering the standard cleanout procedure utilizing a water-tank cleaner-water rinse sequence did not result in greater dicamba removal from contaminated sprayer systems. Finally, increases in time between contamination with dicamba and cleanout did not negatively influence dicamba removal using the standard cleanout procedure.

Master of Science

La cellulose, composé organique le plus courant et polysaccharide le plus abondant sur Terre, est une ressource naturelle très importante. Les initiatives pour remplacer totalement ou partiellement les polymères pétrochimiques conventionnels avec des bio-polymères à base de cellulose ont donc attiré l'intérêt des chercheurs ces dernières décennies, non seulement parce que la cellulose est renouvelable et biodégradable, mais aussi en raison de ses propriétés intéressantes telles que la biocompatibilité et la stabilité chimique. De plus, les propriétés de cellulose peuvent être encore améliorées par des procédés chimiques, des modifications physiques ou en préparant des composites avec des charges fonctionnelles.Les études concernant d'étudier plusieurs aspects fondamentaux comme la dissolution de la cellulose afin de produire des matériaux et le test de nouveaux concepts autour de la modification de surface ou des revêtements, à l'échelle du laboratoire. Nous présentons dans ce manuscrit nos travaux concernant la caractérisation de solutions de cellulose dans deux solvants différents (hydroxyde de sodium aqueux et un liquide ionique) et la préparation de deux nouveaux types de matériaux à base de cellulose (un matériau hybride cellulose-amidon et un composite cellulose-noir de carbone), qui sont tous les deux préparés à partir de ces solutions de cellulose. / Cellulose, as the most common organic compounds on Earth, and also the most abundant polysaccharide, is definitely an important natural resource. With the initiatives of replacing (partially) the conventional petrochemical polymers by bio-based polymers, cellulose has regained the researchers' interests in the last few decades, not only because it is renewable and biodegradable, but also due to interesting properties such as biocompatibility and chemical stability. Additionaly, cellulose properties can be further enhanced by chemical/physical modification or making composites with functional fillers.This study was to investigate several fundamental scientific aspects as cellulose dissolution, making cellulose-based materials from solutions, and test of new concepts as surface modification or coating at laboratory scale. We studied and will present in this manuscript the characterization and properties of both cellulose solutions in different solvents (aqueous sodium hydroxide and ionic liquid) and two types of cellulose-based hybrid materials (one with starch and the other with carbon black), which were all prepared from dissolved cellulose.

Hyaluronic acid is commonly used in dermatological fillers in the form of gels. It is established how these gels' firmness is affected by the amount of cross linker and hyaluronic acid respectively. However, the effect of hydroxide ions in solution is rather unknown. This thesis examines how the alkalinity of the solvent affects the intrinsic viscosity of 3 MDa hyaluronic acid by using the method of Ubbelohde capillary viscometry. Sodium hydroxide solutions between 2 and 10 wt% were prepared to study the variation in intrinsic viscosity at concentrations relevant for cross linking (1<wt%). From these respective solutions, four solutions of different mass concentrations of hyaluronic acid were made. The flow time of respective samples were measured between two points in the capillary viscometer in a controlled temperature of 25 °C with an SI Viscoclock to ensure a high accuracy.From the resulting flow times, the intrinsic viscosity was calculated. The intrinsic viscosity varied between 0,55 and 0,70. The relation between intrinsic viscosity and hydroxide ion concentration had a correlation coefficient r < 0,001. No trend could be ensured as the confidence interval for the intrinsic viscosity at the different concentrations was too large.

Thesis (M.S.)--Mississippi State University. Department of Chemical Engineering. / Title from title screen. Includes bibliographical references.

This dissertation describes the characterisation of, and development of a novel integrated waste management strategy for, hydroxide scouring effluents produced during cotton processing. Such effluents are typical of mineral salt-rich waste waters which are not significantly biodegradable in conventional treatment plants. The proposed strategy focuses on two complementary concepts: process-oriented waste minimisation adopts a systematic approach to identifying potential problems and solutions of waste reduction in the manufacturing process itself; while add-on controls reduce the impact of the waste after it has been generated, by recycling and treatment. The basic procedures for ensuring effective water and chemical management within the scouring process are described. Examples are given of factory surveys, which have resulted in significant chemical and water savings, reduced effluent discharge costs, maximum effluent concentration, and minimum pollutant loading and volume. Pilot-plant investigations demonstrate the technical and economic feasibility of a four stage treatment sequence of neutralisation (using carbon dioxide gas), cross-flow microfiltration, nanofiltration and electrochemical recovery to remove colour and impurities from the scouring effluent and produce directly reusable sodium hydroxide and water. Fouling and scaling of the cross-flow microfiltration, nanofiltration and electrochemical membranes are minimal and reversible if the operation is carried out under carefully selected conditions. A long anode coating life is predicted. Current efficiencies for the recovery of sodium hydroxide (up to 20 % concentration) are 70 to 80 % and the electrical power requirements are 3 500 to 4 000 kWh/tonne of 100 % NaOH. Pilot-plant trials are supplemented by extensive laboratory tests and semi-quantitative modelling to examine specific aspects of the nanofiltration and electrochemical stages in detail. Electromembrane fouling and cleaning techniques, and other anode materials are evaluated. The effects of solution speciation chemistry on the performance of the nanofiltration membrane is evaluated using a combination of speciation and membrane transport modelling and the predicted results are used to explain observed behaviour. Based on the results of pilot-plant trials and supplementary laboratory and theoretical work, a detailed design of an electrochemically-based treatment system and an economic analysis of the electrochemical recovery system are presented. The effects of rinsing variables, processing temperatures, and background rinse water concentrations on the plant size requirements and capital costs are determined. The implementation of the waste management concepts presented in this dissertation will have significant impact on water and sodium hydroxide consumption (decreasing these by up to 95 and 75 % respectively), as well as effluent volumes and pollutant loadings. / Thesis (Ph.D.)-University of Natal, Durban, 1994.

Different pulps were chemically (nitren) and biologically (enzyme) treated in order to improve the chemical accessibility and dissolution capacity in cold NaOH. The treatments effect on the pulp properties was accessed by studying the changes on their chemical and macromolecular structure and by analyzing the dissolution performance in cold NaOH.The nitren treatment has the effect of removing a large part of the xylan present in a dissolving pulp and is also removing mannans. Increasing the nitren concentrations will extract also cellulose and decrease its mean molar mass. These extractions are favorable for the dissolution in cold NaOH–water, being more effective with higher nitren concentrations. A maximum of 44.7% increase on the dissolution yield was achieved.The new enzymatic treatment shows a higher efficiency on promoting fibers accessibility to NaOH ions, (directly correlated with the enzymatic load), allowing a maximum increase of 150% on the dissolution yield. A slight decrease of the average molar mass was also seen. The different pulps reacted differently to the treatments, showing that the pulping pretreatments have an influence on the enzymatic efficiency. Using a mixture of enzymes and endoglucanase showed that the synergistic effect of these two enzymes is more effective on cellulose activation.Both nitren and enzymatic treatments are improving the pulp chemical accessibility mostly by modifying the structure of the primary wall and S1 wall. This promotes the swelling of these wood cell structures, allowing the access of the NaOH solvating ions into fiber regions not accessible on the original pulp. The nitren is disassembling the fiber surface with extraction of hemicelluloses and degrading the cellulosic structure.The use of this enzyme on the cellulose pulps activation towards dissolution in cold NaOH is of great importance. It presents a high potential in both technical, with further development and industrial implementation, and fundamental research fields, with further studies on mechanisms of cellulose activation.The work was performed in Cemef - Mines ParisTech, Sophia Antipolis, France, and TI / Hamburg University, Germany and financed by Sappi, Tembec, Lenzing, Viskase and Spontex and had support from EPNOE (European Polysaccharide Network of Excellence). / Different pulps were chemically (nitren) and biologically (enzyme) treated in order to improve the chemical accessibility and dissolution capacity in cold NaOH. The treatments effect on the pulp properties was accessed by studying the changes on their chemical and macromolecular structure and by analyzing the dissolution performance in cold NaOH.The nitren treatment has the effect of removing a large part of the xylan present in a dissolving pulp and is also removing mannans. Increasing the nitren concentrations will extract also cellulose and decrease its mean molar mass. These extractions are favorable for the dissolution in cold NaOH–water, being more effective with higher nitren concentrations. A maximum of 44.7% increase on the dissolution yield was achieved.The new enzymatic treatment shows a higher efficiency on promoting fibers accessibility to NaOH ions, (directly correlated with the enzymatic load), allowing a maximum increase of 150% on the dissolution yield. A slight decrease of the average molar mass was also seen. The different pulps reacted differently to the treatments, showing that the pulping pretreatments have an influence on the enzymatic efficiency. Using a mixture of enzymes and endoglucanase showed that the synergistic effect of these two enzymes is more effective on cellulose activation.Both nitren and enzymatic treatments are improving the pulp chemical accessibility mostly by modifying the structure of the primary wall and S1 wall. This promotes the swelling of these wood cell structures, allowing the access of the NaOH solvating ions into fiber regions not accessible on the original pulp. The nitren is disassembling the fiber surface with extraction of hemicelluloses and degrading the cellulosic structure.The use of this enzyme on the cellulose pulps activation towards dissolution in cold NaOH is of great importance. It presents a high potential in both technical, with further development and industrial implementation, and fundamental research fields, with further studies on mechanisms of cellulose activation.The work was performed in Cemef - Mines ParisTech, Sophia Antipolis, France, and TI / Hamburg University, Germany and financed by Sappi, Tembec, Lenzing, Viskase and Spontex and had support from EPNOE (European Polysaccharide Network of Excellence).