RESEARCH IN ACTION

Atomic force microscopy to determine the surface roughness and surface polarity of cell types of hardwoods commonly used for pulping

M. Meincken

Department of Forest and Wood Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa. E-mail: mmein@sun.ac.za

ABSTRACT

Atomic force microscopy can be used to determine the surface roughness and surface polarity of different cell types originating from hardwood species. This analytical method allows images representing the topography and polarity of a surface to be captured simultaneously at a molecular (nanometre) resolution. The distribution of hydrophilic (polar) groups on these cell surfaces influences the subsequent processing of woodpulp in paper manufacture. These surface properties of fibres, vessel elements and parenchyma cells were investigated for Acacia mearnsii, Eucalyptus grandis, E. dunnii and E. macarthurii. A clear distinction was observed between the cell types and the species in terms of polarity and surface roughness. All four species are currently being used for paper manufacture in South Africa,butnot with equal success. This study may help to explain the differences in pulp quality obtained for the various species.

“Full text available only in PDF format”

References

1. Dinwoodie J.M. (1965). The relationship between fiber morphology and paper properties. TAPPI48, 440-447.         [ Links ]

2. Horn R.A. (1978). Morphology of pulp fiber from hardwoods and influence on paper strength. For. Prod. Lab., Research Papers 312.         [ Links ]

3. Mahlberg R., Niemi H.E.M., Denes F.S. and Rowell R.M. (1999). Application of AFM on the adhesion studies of oxygen plasma treated polypropylene and lignocellulosics. Langmuir 15, 2985-2992.         [ Links ]

4. Lindstroem T., Soeremark C. and Westman L. (1977). The colloidal behaviour of kraft lignin. Colloid and Polymer Science 258, 168-173.         [ Links ]

5. Fardim P. and Holmbom B. (2005). Origin and surface distribution of anionic groups in different papermaking fibres. Colloids and Surfaces A 252, 237-242.         [ Links ]

6. Hannuksela T., Holmbom B., Mortha G. and Lachenal D. (2003). Effect of sorbed galactoglucomannans on the strength properties of pulp and paper handsheets. Proc. 5th International Paper and Coating Chemistry Symposium, Montreal, June 16-19, 229-232.         [ Links ]

7. Zhang X., Beatson R.P, Cai Y.J. and Saddler J.N. (1999). Accumulation of specific dissolved colloidal substances during white water recycling affecting paper properties. J. Pulp Paper Sci. 25, 206-210.         [ Links ]

8. Futura T. and Gray D.G. (1998). Direct force-distance measurements on wood pulp fibres in aqueous media. J. Pulp Paper Sci. 24, 320-324.         [ Links ]

9. Fardim P., Gustafsson J., von Schoultz S., Peltonen J. and Holbom B. (2005). Extractives on fiber surfaces investigated by XPS, ToF-SIMS and AFM. Colloids and Surfaces A 255, 91-103.         [ Links ]

10. Gustafsson J., Letho J.H., Tienvieri T., Ciovica L. and Peltonen J. (2003). Surface characteristics of thermomechanical pulps. Colloids and Surfaces A 225, 95-104.         [ Links ]

11. Gustafsson J., Ciovica L. and Peltonen J. (2003). The ultrastructure of spruce kraft pulps studied by AFM and XPS. Polymer 44, 661-670.         [ Links ]

12. Kangas H. and Kleen M. (2004). Surface chemical and morphological properties of mechanical pulp fines. Nordic Pulp Paper Res. J. 19, 191-199.         [ Links ]

13. Koljonen K. (2004). Effect of surface properties of fibres on somepaper properties of mechanical and chemical pulp. Ph.D. thesis, Helsinki University of Technology, Finland.         [ Links ]

14. Marti O., Stifter T., Waschipky H. and Quintus M., Hild S. (1999). Scanning probe microscopy of heterogeneous polymers. Colloids andSurfaces154, 65-73.         [ Links ]

15. Krotil H., Stifter T, Waschipky H., Weishaupt K., Hild S. and Marti O. (1999). Pulsed force mode: a new method for the investigation of surface properties. Surf. Interf. Anal. 27, 33^340.         [ Links ]

16. Meincken M., Roux S.P. and Jacobs E.P. (2005). Determination of the hydrophilic character of membranes by pulsed force mode atomic force microscopy. Appl. Surf. Sci. 252, 1772-1779.         [ Links ]

17. Han J.S., Mianowski T. and Lin Y. (1999). Validity of plant fiber length measurement. In Kenaf Properties, Processing and Products, pp. 149-167. Mississippi State University.         [ Links ]

18. Jarvis S.P. and Pethica J.B. (1996). Comparison of hydrophobic modifying layers in SiO² studied with a force-controlled AFM. Thin Solid Films 273, 284-288.         [ Links ]