1. Virginia Tech, Department of Chemical Engineering, Blacksburg, VA 24061, United States;2. University of Kentucky, Department of Chemical and Materials Engineering, Lexington, KY 40506, United States;1. Building Materials, Lund University, Sweden;2. SP Sustainable Built Environment, Stockholm, Sweden;1. School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, USA;2. Institute for Electronics and Nanotechnology, Georgia Institute of Technology, Atlanta, GA, USA;3. Analog Devices Inc., Dallas Design Center, Plano, TX, USA;4. Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA;5. Department of Pediatrics, Division of Pediatric Hematology/Oncology, Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children’s Healthcare of Atlanta/Emory University School of Medicine, Atlanta, GA, USA;1. Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China;2. Zhejiang Gongshang University, Hangzhou 310018, China;3. Institute of Environment Resource and Soil Fertilizer, Zhejiang Academy of Agriculture Science, Hangzhou 310021, China;4. School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, 311300 Lin an, Zhejiang, China;5. Department of Chemical and Biomolecular Engineering, Vanderbilt University, 37235-1604, Nashville, TN, USA
Abstract:
It is shown that the formation of true hydrates plays a part in the process of moisture absorption in cellulose fibers. The existence of two hydrates, called hydrate I and hydrate II, can be derived from X-ray data.Crystalline hydrate I is formed when cellulose II (the modification of “mercerized” cellulose) is exposed to water vapor and hence this modification, in contrast to current statements in the literature, exhibits so-called “intramicellar” swelling. Cellulose I (native modification) does not show this phenomenon.Crystalline hydrate II is identical with the “water cellulose” of Sakurada and Hutino. It is formed when other cellulose compounds containing water are decomposed at low temperature.The lattice constants of both hydrates are given in Table II. If their composition be expressed by C6H10O5·pH2O the value of p is most probably 13 role=presentation style=font-size: 90%; display: inline-block; position: relative;> or 12 role=presentation style=font-size: 90%; display: inline-block; position: relative;> in hydrate I and 113 role=presentation style=font-size: 90%; display: inline-block; position: relative;> or 112 role=presentation style=font-size: 90%; display: inline-block; position: relative;> in hydrate II.The point of view is adopted that the crystalline part of fibers consisting of cellulose II takes part in the process of sorption by the formation of hydrate I, whereas crystalline cellulose I does not. In the amorphous part of the fiber both hydrates are always formed if sufficient water is absorbed.
