Download or read book Adsorption of Polyelectrolytes Onto Cellulosic Fibres and Other Charged Surfaces written by Rein Aksberg and published by . This book was released on 1990 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paper Chemistry and Technology written by Monica Ek and published by Walter de Gruyter. This book was released on 2009 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The production of forestry products is based on a complex chain of knowledge in which the biological material wood with all its natural variability is converted into a variety of fiber-based products, each one with its detailed and specific quality requirements. This four volume set covers the entire spectrum of pulp and paper chemistry and technology from starting material to processes and products including market demands. Supported by a grant from the Ljungberg Foundation, the Editors at the Royal Institute of Technology, Stockholm, Sweden coordinated over 30 authors from university and industry to create this comprehensive overview. This work is essential for all students of wood science and a useful reference for those working in the pulp and paper industry or on the chemistry of renewable resources."--Publisher's description.
Download or read book The Effects of Cellulosic Fiber Charges on Polyelectrolyte Adsorption and Fiber fiber Interactions written by A. Elisabet Horvath and published by . This book was released on 2006 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surface charges of cellulosic fibers contribute to several papermaking operations that influence the manufacture and final properties of paper. This thesis investigates the effect of the surface charges on wet-end chemistry, e.g. through the interaction of cationic polyelectrolytes with the fiber surface charges, and on the network strength of pulp suspensions. The polyelectrolyte titration method was used to investigate the interaction of the fiber charges with cationic polyelectrolytes. Techniques were developed to fluorescent label the adsorbing cationic polyelectrolyte in order to visualize the adsorption behavior. Fluorescent confocal laser scanning microscopy (CLSM) was used to determine the extent to which the cationic polyelectrolyte adsorbs into the porous fiber wall. It was shown that the polyelectrolyte charge density limits the adsorption to the surface under electrolyte-free conditions. Adsorption into the fiber wall only occurs for two conditions: 1) if the molecular mass is sufficiently low or 2) the electrolyte concentration is high enough to screen the charges along the polyelectrolyte backbone but not the interactions between the polyelectrolyte and the fiber charges.Aside from the polyelectrolyte properties, the fiber charge density contributes to the adsorption behavior of cationic polyelectrolytes. The fiber charge profile was altered by bulk and surface carboxymethylation. The electrolyte concentration at which a deviation from 1:1 stoichiometry occurs was shown to be dependent on the amount of surface charges, such that the deviation in stoichiometry occurs at a higher electrolyte concentration for pulps having a higher surface charge. A hypothesis was developed to test the conditions at which the deviation in adsorption stoichiometry occurs, which was defined as the critical electrolyte concentration (CEC). It was found that the CEC corresponded to the electrolyte concentration at which the distance between the fiber charges was on the order of the Debye length. Electron spectroscopy for chemical analysis (ESCA) was used as an independent calibration procedure to validate for which a 1:1 stoichiometry occurs. The analysis with ESCA agreed well with the polyelectrolyte titration method for measurement of fiber surface charges. When measured under appropriate conditions, i.e. electrolyte concentration and molecular properties, the fiber surface charge can accurately be measured by the polyelectrolyte titration method.The charge profiles of various pulp types and treatments were also examined. Having been established as a valid technique, the polyelectrolyte titration method was again used to measure the surface charge while conductometric titration was used to measure the total charge content. The amount of bulk and surface charges vary depending on the pulping method and type of wood, although the ratio between the bulk and surface charge (i.e. the charge ratio) is similar for chemical pulps. The mechanical pulp has a higher charge ratio because it contains more fines material than chemical pulp. Bleaching of the chemical pulp decreases the amount of bulk and surface charges, although the charge ratio remains essentially constant. However, methods such as beating or carboxymethyl cellulose (CMC) grafting are available to increase the charge ratio.The effect of the charge profile on fiber-fiber interactions was studied on both a microscopic and macroscopic level. Colloidal probe microscopy (CPM) was used to investigate the microscopic interactions between two cellulose surfaces. Cellulose surfaces, prepared by spin-coating a dissolving pulp onto silica, were used to model the fiber surface, which is too rough for surface force measurements. The charge density of the model surface was increased by CMC grafting. Results showed that increasing the surface charge density created large electrosteric repulsions, due to CMC the chains protruding out from the surface. These interactions on the microscopic scale affect the fiber network strength, which was measured with a parallel plate rheometer. When the repulsion is increased between the fibers, caused by the increase in the surface charge, fiber flocs break apart more easily due to a reduced friction between the fiber surfaces.The forces acting on the fiber network can also be mechanical in origin. The fiber length and flexibility were altered in order to study the influence of mechanical surface linking and elastic fiber bending on the fiber network strength. Using the storage modulus (G'0) as a measure of fiber network strength, longer fibers were found to create a stronger network due to an increased amount of fiber contacts. Flexible fibers have a lower network strength than stiff fibers because the fibers come to rest in a less strained position such that the the influence of elastic fiber bending on the fiber network strength is predominant.
Download or read book Polyelectrolyte Complexes in the Dispersed and Solid State II written by Martin Müller and published by Springer. This book was released on 2013-08-23 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polyelectrolyte Complexes for Tailoring of Wood Fibre Surfaces. Polyelectrolyte Complexes in Flocculation Applications. Spontaneous Assembly and Induced Aggregation of Food Proteins. Polyelectrolyte Complexes of DNA and Polycations as Gene Delivery Vectors. Sizing, Shaping and Pharmaceutical Applications of Polyelectrolyte Complex Nanoparticles.
Download or read book Polyelectrolyte Adsorption on Wood Fibers written by Joanna Lee Koethe and published by . This book was released on 1992 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polysaccharide based Fibers and Composites written by Lucian Lucia and published by Springer. This book was released on 2017-09-02 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes chapters based on the potential uses of polysaccharides such as fibers in food and non-food applications. The complexity of their synthesis in plants, the highly multidisciplinary character of polysaccharide research, and the wide variety of applications from food to clothing to energy are addressed in this volume. The authors describe in detail how these latter grand challenges are of great importance in research, especially in the midst of enormous overpopulation and economic issues. Therefore, the volume contributes additional information to the chemical, nutritional, medical, and energy roles of these bio-based products, finding applications in diverse fields of their raw and composite forms. This volume is a useful resource for graduate students and contains themes for instructors and senior research leaders. Written by internationally renowned experts, it is aimed at workers in polymer laboratories, classrooms, and policy makers.
Download or read book Pulp Production and Processing written by Valentin Popa and published by Smithers Rapra. This book was released on 2013-09-23 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellulose represents the most widely spread organic polymer found in nature and it was used for a long time as a raw material for paper, textiles, film and flexible packing material. Due to its accessibility in huge amounts by photosynthesis process as a renewable material, cellulose is considered at present the answer to many problems connected with sustainable development. This explains the great scientific interest for this compound along with a lot of preoccupations to systematize the accumulated information in reviews and books. This book will present the aspects of cellulose obtaining in the correleation with its integration in a new concept of biorefining. Thus usual technological steps of pulp manufacture (pulping, bleaching) will be continued with chemistry charactersitics of by-products and their utilization, fiber characterization for paper obtaining, cellulose derivatives and special products resulted in cellulose processing (beads and microspheres, micro-and nano-structures, fibers production, their antibacterial properties, optical functional film, and hydrogen). This extensive book should prove to be a very useful tool for scientists, students and postgraduates working in the field of pulp, paper and cellulose derivatives aiming at opening a new era for renewable resources processed by biorefining.
Download or read book Chemistry of Modern Papermaking written by Cornel Hagiopol and published by CRC Press. This book was released on 2011-09-08 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemistry of Modern Papermaking presents a chemist's perspective on the papermaking process. With roughly 3% of the mass of a paper product invested in water-soluble chemicals, paper makers can adjust the speed and efficiency of the process, minimize and reuse surplus materials, and differentiate a paper product as required by specific customers. W
Download or read book Smart and Green Interfaces Conference SGIC2015 written by Zoran Šaponjić and published by Institut za nuklearne nauke VINČA. This book was released on 2015-03-12 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ништа није унето
Download or read book Textile Chemistry written by Thomas Bechtold and published by Walter de Gruyter GmbH & Co KG. This book was released on 2023-04-03 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Textile and fibre chemistry form the theoretical basis to understand production and properties of textile based products. In this 2nd edition fundamentals of textile chemistry and theoretical and applicatory aspects of colour chemistry are interconnected to draw detailed picture of chemical reactions occurring during production and modification of textile products. An overview about chemical modification, finishing operations is given to explain how to impart special functionalities into functional products. Examples for technical scale processes and representative machinery used therein give insight into the technical reality of a dyehouse. A new chapter about circularity of textiles highlights the interlinkage between product design, including dyes and finishes, and the requirements to develop future fibre-to-fibre recycling. The work covers all relevant aspects of a textile product from fibre production, coloration, finishing, consumer use and fibre-to-fibre recycling. The content of the book allows a first entry into this multi-disciplinary field. Through its comprehensive character the authors explain the interdependence between textile and fibre processing and aspects of recycling, which makes the work a valuable source of information to design future textiles for circularity.
Download or read book The Chemistry of Paper written by John Christopher Roberts and published by Royal Society of Chemistry. This book was released on 1996 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: For what is thought of as an essentially mechanical process, paper manufacture involves a large amount of chemistry. The Chemistry of Paper provides an overview of the process of making paper from a chemical perspective. It deals with both the chemistry of paper as a material and the chemistry of its production, setting out the main principles involved at every stage of the process. Early chapters provide a chemical definition of paper in the light of the many uses to which it is put. Subsequent chapters deal with the chemical processes involved in the production of paper: the delignification of the wood fibres performed at elevated temperature and pressure, the bleaching of the cellulose-rich pulp using environmentally-friendly systems, the formation of the pulp into sheets of fibres strengthened by extensive inter-fibre hydrogen bonding, and finally the coating of the sheets in a manner appropriate to their end use. Chemistry is involved at every stage of the process, including carbohydrate chemistry, the chemistry of inorganic pigments and organic resins, colloid and surface chemistry, as well as elements of environmental and analytical chemistry. The Chemistry of Paper provides an informative and entertaining overview of the chemical principles involved. It will be especially suitable for students and others who require an introduction to the chemistry of paper manufacture.
Download or read book Pulp Production and Processing written by Valentin I. Popa and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-07-06 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the aspects of cellulose obtained in correlation with its integration into the new concept of biorefining. The authors detail the individual steps of pulp manufacture as well as properties and fiber characterization techniques for paper, cellulose derivatives and processing by-products. This book is of interest to scientists and advanced students working in the fields of renewable resources and biorefining.
Download or read book Encyclopedia of Surface and Colloid Science written by P. Somasundaran and published by CRC Press. This book was released on 2006 with total page 1014 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Powders and Fibers written by Michel Nardin and published by CRC Press. This book was released on 2006-12-21 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: New analytical methods have provided further insight into the structure, surface characteristics, and chemistries of increasingly small particles. However, current literature offers information on only a limited number of powders being investigated. Written by renowned scientists in the field, Powders and Fibers: Interfacial Science and Application
Download or read book Lignocellulosic Fibers and Wood Handbook written by Mohamed Naceur Belgacem and published by John Wiley & Sons. This book was released on 2016-04-05 with total page 1289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will focus on lignocellulosic fibres as a raw material for several applications. It will start with wood chemistry and morphology. Then, some fibre isolation processes will be given, before moving to composites, panel and paper manufacturing, characterization and aging.
Download or read book The European Polysaccharide Network of Excellence EPNOE written by Patrick Navard and published by Springer Science & Business Media. This book was released on 2012-12-13 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an essential overview of the science of polysaccharides. It both approaches polysaccharides as a polymer class and provides detailed descriptions of most major polysaccharides (cellulose, mannan, xylan, chitin-chitosan, cyclodextrines). Owing to the multidisciplinary character of the European Polysaccharide Network of Excellence (EPNOE), the book describes all main aspects of polysaccharide science and technology (biology, enzymology, physics, chemistry, materials science and processing). Notations and concepts follow a uniform format throughout the whole work in order to create a valuable reference book on the field of polysaccharide science. Owing to the major importance of industry in the EPNOE, concrete applications are also described in detail.
Download or read book Delivery and Controlled Release of Bioactives in Foods and Nutraceuticals written by Nissim Garti and published by Elsevier. This book was released on 2008-01-25 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active ingredients in foods must remain fully functional for as long as necessary and be transported and discharged appropriately to have the desired nutritional effect. Delivery and controlled release systems are an essential way to achieve these aims. This important book reviews how to optimise these systems to maximise the health-promoting properties of food products.Opening chapters review factors affecting nutrient bioavailability and methods to test delivery system efficacy. Part two addresses materials used and specific techniques for delivery and release. The benefits and drawbacks of structured lipids, micro- and nano-emulsions, food-protein-derived materials, complexes and conjugates of biopolymers, and starch as an encapsulation material for delivery of functional food ingredients, are all considered. Part three discusses the delivery and controlled release of particular nutraceuticals such as antioxidants and vitamins, folic acid, probiotics, fish oils and proteins. Part four covers regulatory issues and future trends in bioactives and nutraceuticals.Edited by a leading expert in the field, Delivery and controlled release of bioactives in foods and nutraceuticals is a valuable reference for those working in the food industry and particularly those developing nutraceuticals. - Reviews techniques to optimise the delivery and release of bioactives in food - Discusses the factors that affect nutrient bioavailability and methods to test delivery system efficacy - Addresses materials used and specific techniques for delivery and release
