ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Cellulosic hydrogels in bead form were prepared by dropwise addition of cellulose solutions in N,N-dimethylacetamide (DMAc) and lithium chloride (LiCl) to azeotropic methanol or isopropanol as nonsolvent. Bead properties were examined in relation to cellulose solution concentration, viscosity, and molecular weight. Bead properties were defined in terms of solids content, flow characteristics, mechanical strength, bead size, and pore dimensions. Results suggest that (a) beads can be prepared with solids content ranging from 2 to 12 wt %, depending on solution concentration; (b) uniform spherical shapes require a viscosity range between 100 and 300 cS: (c) beads can be produced in different sizes, within the diameter range of 100 to 1,500 μm; (d) linear flow velocities of packed bead columns are in the range of 70 to 350 cm/min; and (e) pore sizes of beads vary between 8 to 200 Å. Beads with low cellulose concentration show a wide fractionation range of up to 200,000 g/mol for polyethylene oxide. © 1996 John Wiley & Sons, Inc.
Additional Material:
16 Ill.
Type of Medium:
Electronic Resource
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