Pickering emulsions (emulsions stabilized by solid-state additives) are attractive as they have strong similarities with traditional surfactant-based emulsions. In this study, an oil-in-water (O/W) paraffin Pickering emulsion system with satisfying stability and small droplet size distribution was developed by hydrophilic silica particles and traditional surfactants as mixed emulsifiers. The droplet morphology and size distribution were observed by optical microscopy and a laser particle analyzer. The emulsion stability was improved and the droplet size was reduced after addition of a suitable amount of silica particles. The silica concentration of 1% showed the optimal effect among all the levels observed (0.1, 0.5, 1 and 2%). Wood was impregnated with the prepared emulsion, and the chemical and morphological properties of the product were investigated by Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) combined with energy-dispersed X-ray analysis (SEM-EDXA). Moreover, the hydrophobicity, thermal properties, surface hardness, axial compression strength (CS) and dynamic mechanical properties were tested. The silica was evenly distributed in the wood cell wall and thus there was a synergistic positive effect from the paraffin and silica in the cell wall leading to better hydrophobicity, improved surface hardness and mechanical properties including the thermal stability.
This study was financially supported by the National Natural Science Foundation of China (Funder Id: 10.13039/501100001809, Grant Number: 31570542).
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: None declared.
Employment or leadership: None declared.
Honorarium: None declared.
Chau, T., Ma, E., Cao, J. (2015) Moisture adsorption and hygroexpansion of paraffin wax emulsion-treated southern pine (Pinus spp.). BioResources 10:2719–2731.10.15376/biores.10.2.2719-2731Search in Google Scholar
Destribats, M., Gineste, S., Laurichesse, E., Tanner, H., Leal-Calderon, F., Héroguez, V., Schmitt, V. (2014) Pickering emulsions: what are the main parameters determining the emulsion type and interfacial properties? Langmuir 30:9313–9326.10.1021/la501299uSearch in Google Scholar
Esteves, B., Nunes, L., Domingos, I., Pereira, H. (2014) Improvement of termite resistance, dimensional stability and mechanical properties of pine wood by paraffin impregnation. Eur. J. Wood Wood Prod. 72:609–615.10.1007/s00107-014-0823-7Search in Google Scholar
Evans, P., Wingate, H.R., Cunningham, R. (2009) Wax and oil emulsion additives: how effective are they at improving the performance of preservative-treated wood? Forest Prod. J. 59:66–70.Search in Google Scholar
Frelichowska, J., Bolzinger, M.A., Chevalier, Y. (2009) Pickering emulsions with bare silica. Colloids Surf. A: Physicochem. Eng. Aspects 343:70–74.10.1016/j.colsurfa.2009.01.031Search in Google Scholar
Frelichowska, J., Bolzinger, M.A., Chevalier, Y. (2010) Effects of solid particle content on properties of O/W Pickering emulsions. J. Colloid Interface Sci. 351:348–356.10.1016/j.jcis.2010.08.019Search in Google Scholar
Gun’ko, V.M., Zarko, V.I., Leboda, R., Chibowski, E. (2001) Aqueous suspension of fumed oxides: particle size distribution and zeta potential. Adv. Colloid Interface Sci. 91:1–112.10.1016/S0001-8686(99)00026-3Search in Google Scholar
Humar, M., Kržišnik, D., Lesar, B., Thaler, N., Ugovšek, A., Zupančič, K., Žlahtič, M. (2017) Thermal modification of wax-impregnated wood to enhance its physical, mechanical, and biological properties. Holzforschung 71:57–64.10.1515/hf-2016-0063Search in Google Scholar
Islam, M.S., Hamdan, S., Talib, Z.A., Ahmed, A.S., Rahman, M.R. (2012) Tropical wood polymer nanocomposite (WPNC): the impact of nanoclay on dynamic mechanical thermal properties. Compos. Sci. Technol. 72:1995–2001.10.1016/j.compscitech.2012.09.003Search in Google Scholar
Jiang, J., Wang, W., Shen, H., Wang, J., Cao, J. (2017) Characterization of silica particles modified with γ-methacryloxypropyltrimethoxysilane. Appl. Surf. Sci. 397:104–111.10.1016/j.apsusc.2016.11.075Search in Google Scholar
Kanokwijitsilp, T., Traiperm, P., Osotchan, T., Srikhirin, T. (2016) Development of abrasion resistance SiO2 nanocomposite coating for teak wood. Prog. Org. Coat. 93:118–126.10.1016/j.porgcoat.2015.12.004Search in Google Scholar
Lesar, B., Straže, A., Humar, M. (2011) Sorption properties of wood impregnated with aqueous solution of boric acid and montan wax emulsion. J. Appl. Polym. Sci. 120:1337–1345.10.1002/app.33196Search in Google Scholar
Liu, C., Wang, S., Shi, J., Wang, C. (2011) Fabrication of superhydrophobic wood surfaces via a solution-immersion process. Appl. Surf. Sci 258:761–765.10.1016/j.apsusc.2011.08.077Search in Google Scholar
Liu, C., Zhang, Y., Li, X., Luo, J., Gao, Q., Li, J. (2017) “Green” bio-thermoset resins derived from soy protein isolate and condensed tannins. Ind. Crops Prod. 108:363–370.10.1016/j.indcrop.2017.06.057Search in Google Scholar
Mai, C., Militz, H. (2004) Modification of wood with silicon compounds. Inorganic silicon compounds and sol-gel systems: a review. Wood Sci. Technol. 37:339–348.10.1007/s00226-003-0205-5Search in Google Scholar
Najafi, A., Golestani-Fard, F., Rezaie, H.R. (2011) A study on sol-gel synthesis and characterization of SiC nano powder. J. Sol-Gel Sci. Technol. 59:205–21410.1007/s10971-011-2482-zSearch in Google Scholar
Ogiso, K., Saka, S. (1993) Wood-inorganic composites prepared by sol-gel process. II. Effects of ultrasonic treatments on preparation of wood-inorganic composites. Mokuzai Gakkaishi 39:301–307.Search in Google Scholar
Pandey, K.K. (1999) A study of chemical structure of soft and hardwood and wood polymers by FTIR spectroscopy. J. Appl. Polym. Sci. 71:1969–1975.10.1002/(SICI)1097-4628(19990321)71:12<1969::AID-APP6>3.0.CO;2-DSearch in Google Scholar
Pichot, R., Spyropoulos, F., Norton, I.T. (2010) O/W emulsions stabilised by both low molecular weight surfactants and colloidal particles: the effect of surfactant type and concentration. J. Colloid Interface Sci. 352:128–135.10.1016/j.jcis.2010.08.021Search in Google Scholar
Salari, A., Tabarsa, T., Khazaeian, A., Saraeian, A. (2013) Improving some of applied properties of oriented strand board (OSB) made from underutilized low quality paulownia (Paulownia fortunie) wood employing nano-SiO2. Ind. Crops Prod. 42:1–9.10.1016/j.indcrop.2012.05.010Search in Google Scholar
Scholz, G., Van den Bulcke, J., Boone, M., Zauer, M., Bäucker, E., Van Acker, J., Militz, H. (2010) Investigation on wax-impregnated wood. Part 1: microscopic observations and 2D X-ray imaging of distinct wax types. Holzforschung 64:581–585.10.1515/hf.2010.091Search in Google Scholar
Stiller, S., Gers-Barlag, H., Lergenmueller, M., Pflucker, F., Schulz, J., Wittern, K.P., Daniels, R. (2004) Investigation of the stability in emulsions stabilized with different surface modified titanium dioxides. Colloids Surf. A: Physicochem. Eng. Aspects 232:261–267.10.1016/j.colsurfa.2003.11.003Search in Google Scholar
Suin, S., Maiti, S., Shrivastava, N.K., Khatua, B.B. (2014) Mechanically improved and optically transparent polycarbonate/clay nanocomposites using phosphonium modified organoclay. Mater. Des. 54:553–563.10.1016/j.matdes.2013.08.091Search in Google Scholar
Sun, M., Cao, J. (2016) A comparison on penetration of silica sols in Scots Pine and Southern Pine. Doc. No. WP 04-60184. The 47th Annual Meeting of the International Research Group on Wood Protection, Lisbon, Portugal.Search in Google Scholar
Tarrio-Saavedra, J., López-Beceiro, J., Naya, S., Artiaga, R. (2008) Effect of silica content on thermal stability of fumed silica/epoxy composites. Polym. Degrad. Stab. 93:2133–2137.10.1016/j.polymdegradstab.2008.08.006Search in Google Scholar
Tsoumis, G. Science and Technology of Wood: Structure, Properties, Utilization. Van Nostrand Reinhold, New York, 1991.Search in Google Scholar
Uphill, S.J., Cosgrove, T., Wuge, H.B. (2014) Flow of nanofluids through porous media: preserving timber with colloid science. Colloids Surf. A: Physicochem. Eng. Aspects 460:38–50.10.1016/j.colsurfa.2014.05.008Search in Google Scholar
Wang, W., Zhu, Y., Cao, J. (2014) Morphological, thermal and dynamic mechanical properties of Cathay poplar/organoclay composites prepared by in situ process. Mater. Des. 59:233–240.10.1016/j.matdes.2014.02.059Search in Google Scholar
Wang, W., Zhu, Y., Cao, J., Guo, X. (2015) Thermal modification of Southern pine combined with wax emulsion preimpregnation: effect on hydrophobicity and dimensional stability. Holzforschung 69:405–413.10.1515/hf-2014-0106Search in Google Scholar
Wang, W., Chen, C., Cao, J., Zhu, Y. (2018a) Improved properties of thermally modified wood (TMW) by combined treatment with disodium octoborate tetrahydrate (DOT) and wax emulsion (WE). Holzforschung, online 25.10.2017. 72:2437#x2013;250.10.1515/hf-2017-0043Search in Google Scholar
Wang, W., Huang, Y., Cao, J., Zhu, Y. (2018b) Penetration and distribution of paraffin wax in wood of loblolly pine and Scots pine studied by time domain NMR spectroscopy. Holzforschung, online 29.09.2017. 72:125–131.10.1515/hf-2017-0030Search in Google Scholar
Yan, Y., Dong, Y., Li, J., Zhang, S., Xia, C., Shi, S.Q., Cai, L. (2015) Enhancement of mechanical and thermal properties of Poplar through the treatment of glyoxal-urea/nano-SiO2. RSC Adv. 5:54148–54155.10.1039/C5RA07294HSearch in Google Scholar
©2018 Walter de Gruyter GmbH, Berlin/Boston