Thesis (Ph. D.)--Institute of Paper Chemistry, 1957. / Bibliography: leaves 112-114.

Thesis(M.S.)--Auburn University, 2005. / Abstract. Vita. Includes bibliographic references.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Includes bibliographic references (p.69-73).

The objectives of this work were (i) to develop a new methodfor the preparation of thin cellulose model films, (ii) to usethese model films for swelling measurements and (iii) to relatethe swelling of fibers and films to the dry strength ofpaper. In the new film preparation method, NMMO(N-methylmorpholine-N-oxide) was used to dissolve cellulose andDMSO (dimethyl sulfoxide) was added to control the viscosity ofthe cellulose solution. A dilute solution of the cellulose wasspin-coated onto a silicon oxide wafer and the cellulose filmthus prepared was then precipitated in deionised water. Asaturated layer of glyoxalated-polyacrylamide was used toanchor the film onto the silicon oxide wafer. This proceduregave films with thicknesses in the range of 20-270 nm. Thefilms were cleaned in deionised water and were found by ESCAanalysis and contact angle measurements (θ&lt;20°)to be free from solvents. Solid state NMR measurements onfibers spun from NMMO also indicated that the model filmconsisted of about 50% crystalline material and that thecrystalline structure was of the cellulose II type.Determination of the molecular weight distribution of thecellulose surface material showed that the NMMO treatmentcaused only a minor breakdown of the cellulose chains and thatlow molecular mass oligomers of glucose were not created. It was further shown that atomic force microscopy (AFM)measurements could be used to determine the thicknessof thecellulose films, in both the dry and wet states. The thicknesswas determined as the height difference between the top surfaceand the underlying silica wafer measured at a position where anincision had been made in the cellulose film. The cellulosesolutions were also directly spin-coated onto the crystal usedin the Quartz crystal microbalance (QCM-D), pre-treated withthe same type of anchoring polymer. With this application,these model surfaces were shown to be suitable for swellingmeasurements with the QCM-D. The extent of swelling and theswelling kinetics in the presence of electrolytes, such asNaCl, CaCl2 and Na2SO4, and at different pH were measured inthis way. The films were found to be very stable during thesemeasurements and the results were comparable to the swellingresults obtained for the corresponding pulps. The swelling ofboth fibers and films followed the general behavior ofpolyelectrolyte gels in the presence of electrolytes and was inaccordance with the Donnan equilibrium theory. The films havebeen shown to differ from fibers with regard to the absence ofa covalent interior network. This influences the evaluation ofthe deswelling effects measured on the model films. Theswelling effect seen with different electrolytes has also beenconsidered in relation to the tensile strength of paperprepared from a kraftliner-pulp. In this study, it was foundthat there was no direct relationship between the swelling ofthe fibers, measured as WRV, and the strength of the paper inthe presence of different electrolytes at pH 5. KEYWORDS:absorption, carboxymethyl cellulose,cellulose, cellulose fibers, dissolving pulps, donnanequilibrium, electrolytes, film, ion exchange, ionization,kinetics, liner boards, microscopy, spinning, surfaces,swelling, tensile strength, water, water retention value. / <p>NR 20140805</p>

In recent years, there has been a significant amount of research into cellulose nanocrystals (CNCs). These materials are categorized as being between 5 and 10 nm wide and being 100-250 nm long. CNCs have several uses, but the most common is the reinforcement of polymer composites. Here I present 2 papers investigating CNC-based composites. By using standard bleaching procedures, pure cellulose was isolated from pistachio shells. Sulfuric acid was used to isolate cellulose nanocrystals from the purified cellulose. The obtained crystals were investigated by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The CNCs were also added to thermoplastic polyurethane (TPU) to observe the reinforcement effects by dynamic mechanical analysis. Pistachio shells offered a high yield source material for CNCs, with a high aspect ratio but a low crystallinity. They did offer significant reinforcement of the TPU, but less than the commercially available wood-based CNCs. Wood-based CNCs were also mixed with TPU in structured composites to create a film which actuates when exposed to water. The method of actuation is based on the different amounts of absorption of water in the composite as opposed to the pure TPU. The actuation was modeled based on the absorption of water and the modulus of two components. Mechanical properties of the CNC/TPU composites were evaluated via dynamic mechanical analysis, and water absorption was measured gravimetricaly. The tests helped us to evaluate our model which we compared to the composites. / Master of Science / Composites are a category of materials where two or more materials are used together to enhance each of their strengths. Such materials are often used in airplanes, spacecraft, sporting equipment, and many high-end products. Cellulose nanocrystals (CNCs) have been research with the goal of improving the environmental sustainability and performance of composite materials. This newly utilized material is found in plants and some animals to provide them with their strength. Researches have already shown that CNCs can improve the performance of many materials while reducing their lifetime environmental impact. In order to increase the market for CNCs, we are looking at costreducing methods of producing them as well as finding exciting new uses for them once they are made. Right now, most CNCs are isolated from wood or cotton, which already have existing markets. This thesis presents a method of using pistachio shells, which are a waste product in many parts of the world including the United States. By finding new sources of CNCs, we hope to add to the body of knowledge and reduce the price of CNC production. This thesis also lays the groundwork for a material that changes shape when exposed to water. By integrating CNCs into only part of a polymer, when water is added, the part with the CNCs will increase in size, causing it to push on the polymer. Our hope is to create a new use for CNC composites to help to increase the market for them. We discuss potential methods and proofs of concept on how to create a 3D-printed part using CNCs and polyurethane.

Digitized by Kansas Correctional Industries

Call number: LD2668 .T4 1964 A37 / Master of Science

Call number: LD2668 .T4 1979 B424 / Master of Science

Cellooligosaccharides are the reaction intermediates produced during the hydrolysis of cellulose to glucose. Hence, they have the same chemical structure as cellulose, just shorter chain lengths. Cellooligosaccharides up to DP eight are soluble in water. The soluble cellooligosaccharides can be used "as is" in the food industry as non-digestible oligosaccharides and in the laboratory as representative substrates for cellulolytic enzymes. The soluble cellooligosaccharides may also be chemically modified for use in the laboratory, in this case serving as affinity ligands, reporter groups, or model substrates. A number of methods are available for the separation of cellooligosaccharides differing only with respect to DP. This type of separation is relevant to both laboratory and industrial applications. A new approach to the chromatographic separation of cellooligosacchandes is presented in this thesis. It is shown that cellulose stationary phases, in conjunction with ethanol-water mobile phases, may be used for cellooligosaccharide fractionation. The system appears to behave as an affinity/partition system, with retention times increasing as the DP of the cellooligosaccharides increase. The feasibility of using such a chromatographic system for the "clean-up" of cellooligosaccharide mixtures is demonstrated. The relative merit of different chromatographic approaches putatively used for the fractionation of cellooligosaccharides was determined. Affinity-, adsorption-, ion-mediated- and molecular exclusion-approaches were tested. Adsorption chromatography, using a charcoal-celite stationary phase, was the most generally applicable method for the preparation of near gram quantities of pure cellooligosaccharides. Cellulose-based affinity/partition chromatography was found to be the least time consuming and most economical method for the preparation of cellotetraose and cellopentaose. Studies using chemically modified cellooligosaccharides are typically limited to derivatives whose aglycone group is conjugated to the reducing end of the sugar. This is because the chemistry involved in modifying the reducing end is typically much easier than that involved in selectively modifying other sites on the oligosaccharides. A portion of the studies presented herein was aimed at exploring approaches for the modification of the non-reducing end of cellooligosaccharides. Methyl 6-O-p-nitrobenzoyl-β-D-glucoside was synthesized by reacting methyl 4,6-O-p-nitrobenzylidine-β-Dglucoside with N-bromosuccinimide. This method has potential as a general method for the modification of the reducing terminus of oligosaccharides, including, cellooligosaccharides. / Graduation date: 2003

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