Abstract
The penetration characteristics of phenol formaldehyde (PF) resin, modified by two different nanomaterials (PFmod), has been studied by means of scanning thermal microscopy (SThM). The thermal conductivity (ThC) of the two PFmod was lower than that of the cell wall (CW), but the ThC of both PF resins was basically the same. SThM imaging revealed the penetration of parts of PFmod into the CW by a ThC transitional region, which exists between the CW and the resin. In the transitional zone, the ThC changed obviously in a region about 2 μm in width. This region includes two subregions, one about 0.7 μm and another 1.3 μm in width. The first one is the interface, where PFmod and the CW are in direct contact where the ThC changes rapidly. In the second subregion, the PFmod and CW are in interaction, and ThC changes slowly. Regarding the adhesives’ penetration into the cell lumen, the ThC of the penetrating adhesive was higher than that in the glue line, and this is an indication that SThM is a useful tool to detect the differences of adhesive penetration at the micro-scale level.
Acknowledgments
The authors thank the Natural Science Foundation of Jiangsu (Grant No. BK20130971) and National Natural Science Foundation of China (Grant No. 31300483). The project was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, Jiangsu Province Graduate Education Innovation Project (Grant No. CXZZ12_0534), UTIA 2011 Innovation Grant, and Tennessee Agricultural Experimental Station TEN00422, which are acknowledged for their financial support.
References
Barral, L., Cano, J., Díez, F., López, J., Ramírez, C., Abad, M., Ares, A. (2002) Analysis of blends of poly(styrene-co-acrylonitrile) with an epoxy/aromatic amine resin using scanning thermal microscopy. J. Polym. Sci. B Polym. Phys. 40:284–289.Search in Google Scholar
Binnig, G., Quate, C.F., Gerber, C. (1986) Atomic force microscope. Phys. Rev. Lett. 56:930–933.10.1103/PhysRevLett.56.930Search in Google Scholar PubMed
Binnig, G., Rohrer, H. (1983) Scanning tunneling microscopy. Surf. Sci. 126:236–244.Search in Google Scholar
Callard, S., Tallarida, G., Borghesi, A., Zanotti, L. (1999) Thermal conductivity of SiO2 films by scanning thermal microscopy. J. Non-Cryst. Solids 245:203–209.Search in Google Scholar
Fischer, H. (2005) Quantitative determination of heat conductivities by scanning thermal microscopy. Thermochim. Acta 425:69–74.Search in Google Scholar
Gardner, D.J., Generalla, N. C., Gunnells, D. W., Wolcott, M. P. (1991) Dynamic wettability of wood. Langmuir 7:2498–2502.10.1021/la00059a017Search in Google Scholar
Gmelin, E., Fischer, R., Stitzinger, R. (1998) Sub-micrometer thermal physics – an overview on SThM techniques1. Thermochim. Acta 310:1–17.Search in Google Scholar
Guo, F., Trannoy, N., Lu, J. (2006) Characterization of the thermal properties by scanning thermal microscopy in ultrafine-grained iron surface layer produced by ultrasonic shot peening. Mater. Chem. Phys. 96:59–65.10.1016/j.matchemphys.2005.05.055Search in Google Scholar
Hammiche, A., Pollock, H., Song, M., Hourston, D. (1996) Sub-surface imaging by scanning thermal microscopy. Meas. Sci. Technol. 7:142.Search in Google Scholar
Hass, P., Wittel, F.K., Mendoza, M., Herrmann, H.J., Niemz, P. (2012) Adhesive Lee penetration in beech wood: experiments. Wood Sci. Tech. 46:243–256.Search in Google Scholar
Jensen, E.S., Gatenholm, P., Sellitti, C. (1992) An ATR-FTIR study on penetration of resins in wood. Angew. Makromol. Chem. 200:77–92.Search in Google Scholar
Kamke, F.A., Lee, J.N. (2007) Adhesive penetration in wood – a review. Wood Fib. Sci. 39:205–220.Search in Google Scholar
Kim, J.-K., Mai, Y.-W. Engineered Interfaces in Fiber Reinforced Composites. Access Online via Elsevier, 1998.10.1016/B978-008042695-2/50001-4Search in Google Scholar
Konnerth, J., Harper, D., Lee, S.-H., Rials, T.G., Gindl, W. (2008) Adhesive penetration of wood cell walls investigated by scanning thermal microscopy (SThM). Holzforschung 62:91–98.10.1515/HF.2008.014Search in Google Scholar
Konnerth, J., Valla, A., Gindl, W. (2007) Nanoindentation mapping of a wood-adhesive bond. Appl. Phys. A 88:371–375.Search in Google Scholar
Kotera, M., Urushihara, Y., Izumo, D., Nishino, T. (2012a) Interfacial structure of all-polyethylene laminate by using scanning thermal microscope. Thermochim. Acta 531:1–5.10.1016/j.tca.2011.11.022Search in Google Scholar
Kotera, M., Urushihara, Y., Izumo, D., Nishino, T. (2012b) Interfacial structure of poly-α-olefin laminate using scanning thermal microscope and nano-Raman spectroscope. Polymer 53:1966–1971.10.1016/j.polymer.2012.02.038Search in Google Scholar
Lee, S.-H., Wang, S., Endo, T., Kim, N.-H. (2009) Visualization of interfacial zones in lyocell fiber-reinforced polypropylene composite by AFM contrast imaging based on phase and thermal conductivity measurements. Holzforschung 63:240–247.10.1515/HF.2009.033Search in Google Scholar
Liu, C., Zhang, Y., Wang, S., Meng, Y., Hosseinaei, O. (2014) Micromechanical properties of the interphase in cellulose nanofiber-reinforced phenol formaldehyde bondlines. BioResources 9:5529–5541.10.15376/biores.9.3.5529-5541Search in Google Scholar
Marra, A.A. Technology of Wood Bonding: Principles in Practice. Van Nostrand Reihold, New York, 1992.Search in Google Scholar
McConney, M.E., Singamaneni, S., Tsukruk, V.V. (2010) Probing soft matter with the atomic force microscopies: imaging and force spectroscopy. Polym. Rev. 50:235–286.10.1080/15583724.2010.493255Search in Google Scholar
Meng, Y., Wang, S., Cai, Z., Young, T.M., Du, G., Li, Y. (2013) A novel sample preparation method to avoid embedding medium influence during nanoindentation. Appl. Phys. A-Mater. 110:361–369.Search in Google Scholar
Nair, S.S. (2012) Nanoscale characterization of fiber/matrix interphase and its impact on the performance of natural fiber reinforced polymer composites. Ph.D. dissertation, University of Tennessee, Knoxville. pp. 160.Search in Google Scholar
Price, D.M., Reading, M., Hammiche, A., Pollock, H.M. (1999) Micro-thermal analysis: scanning thermal microscopy and localised thermal analysis. Int. J. Pharm. 192:85–96.10.1016/S0378-5173(99)00275-6Search in Google Scholar
Rapp, A., Bestgen, H., Adam, W., Peek, R.-D. (1999) Electron energy loss spectroscopy (EELS) for quantification of cell-wall penetration of a melamine resin. Holzforschung 53:111–117.10.1515/HF.1999.018Search in Google Scholar
Ruiz, F., Sun, W., Pollak, F.H., Venkatraman, C. (1998) Determination of the thermal conductivity of diamond-like nanocomposite films using a scanning thermal microscope. Appl. Phys. Lett. 73:1802–1804.Search in Google Scholar
Vay, O., Obersriebnig, M., Müller, U., Konnerth, J., Gindl-Altmutter, W. (2013) Studying thermal conductivity of wood at cell wall level by scanning thermal microscopy (SThM). Holzforschung 67:155–159.10.1515/hf-2012-0052Search in Google Scholar
Wright, J., Mathias, L.J. (1993) Physical characterization of wood and wood-polymer composites: An update. J. Appl. Polym. Sci. 48:2225–2239.Search in Google Scholar
Wu, Q., Meng, Y., Concha, K., Wang, S., Li, Y., Ma, L., Fu, S. (2013) Influence of temperature and humidity on nano-mechanical properties of cellulose nanocrystal films made from switchgrass and cotton. Ind. Crops. Prod. 48:28–35.Search in Google Scholar
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