Contact Angle Measurement of Wood Fibers in Surfactant and Polymer Solutions
Keywords:Contact angle, hydrophobic, wood fiber, wettability, surfactant, polymer, adsorption
The Wilhelmy principle was used to investigate the wettability of wood fibers in various aqueous solutions. The sensitivity and reproducibility of the measurement were significantly improved by using a group of separated fibers as compared to a single-fiber method that was reported previously. This accurate and reproducible method allowed us to investigate contact angle and wettability of wood fibers in aqueous solutions using a common dynamic contact angle analyzer without the interference of capillary and roughness from the paper sheet surface.
The wettability of different solutions on various wood fibers, including bleached and unbleached, and AKD (alkyl ketene dimer) sized and unsized fibers, was studied. The results indicated that the receding contact angle of aqueous solution against wood fibers is zero or close to zero regardless of the nature of the wood fiber surface. However, the advancing contact angle of aqueous solution against wood fibers strongly depends on the fiber surface properties.
A decrease in advancing contact angle with an increase of the surfactant concentration was observed for all types of surfactants and fibers used in this study. The water-soluble cationic polyDADMAC [poly(diallydimethylammonium chloride)] and nonionic PEO (polyethylene oxide) have no significant effect on the wettability of wood fibers in aqueous solutions.
Foote, J. 1939. A method for the measurement of the angle of contact formed between a liquid surface and a fiber, and the application of this and swelling data to pore diameter measurements. Paper Trade J. 10:40-48.nGrindstaff, T. 1969. A simple apparatus and technique for contact-angle measurements on small-denier single fibers. Textile Res. J. 39:958-962.nHodgson, K., and J. Berg. 1988. Dynamic wettability properties of single wood pulp fibers and their relationship to absorbency. Wood Fiber Sci. 20(1):3-17.nJones, W., and M. Porter. 1967. A method for measuring contact angles on fibers. J. Colloid Interface Sci. 24:1-3.nKlungness, J. 1981. Measuring the wetting angle and perimeter of single wood pulp fibers: A modified method. Tappi 64(12):65-66.nKrueger, J., and K. Hodgson. 1994. Single-fiber wettability of high sized pulp fibers. Tappi 77(7):83-87.nKrueger, J., and K. Hodgson. 1995. The relationship between single fiber contact angle and sizing performance. Tappi 78(2):154-161.nLi, M., and M. Muvundamina. 1994. Fractionation of recycled pulps obtained from mixed paper. Pages 303-308 in 1994 TAPPI Recyclcing Symp., Atlanta, TAPPI Press.nLi, M., and M. Muvundamina. 1995. Fractionation of fiber slurries via froth flotation and sedimentation. Prog. Paper Recycling. 4(3):32-38.nYoung, R. 1976. Wettability of wood pulp fibers, applicability of methodology. Wood Fiber 8(2): 120-128.n
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.