Department of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695-8005, USA.
J Colloid Interface Sci. 2012 Sep 1;381(1):171-9. doi: 10.1016/j.jcis.2012.05.032. Epub 2012 May 30.
A new approach based on microemulsions formulated with at least 85% water and minority components consisting of oil (limonene) and surfactant (anionic and nonionic) is demonstrated for the first time to be effective for flooding wood's complex capillary structure. The formulation of the microemulsion was based on phase behavior scans of Surfactant-Oil-Water systems (SOWs) and the construction of pseudo-ternary diagrams to localize thermodynamically stable one-phase emulsion systems with different composition, salinity and water-to-oil ratios. Wicking and fluid penetration isotherms followed different kinetic regimes and indicated enhanced performance relative to that of the base fluids (water, oil or surfactant solutions). The key properties of microemulsions to effectively penetrate the solid structure are discussed; microemulsion formulation and resultant viscosity are found to have a determining effect in the extent of fluid uptake. The solubilization of cell wall components is observed after microemulsion impregnation. Thus, the microemulsion can be tuned not only to effectively penetrate the void spaces but also to solubilize hydrophobic and hydrophilic components. The concept proposed in this research is expected to open opportunities in fluid sorption in fiber systems for biomass pretreatment, and delivery of hydrophilic or lipophilic moieties in porous, lignocellulosics.
首次提出了一种基于微乳液的新方法，该微乳液由至少 85%的水和少数成分组成，包括油（柠檬烯）和表面活性剂（阴离子和非离子），可有效填充木材的复杂毛细管结构。微乳液的配方是基于表面活性剂-油-水系统（SOW）的相行为扫描和拟三元相图的构建，以定位具有不同组成、盐度和油水比的热力学稳定单相乳液系统。润湿和流体渗透等温线遵循不同的动力学规律，与基础流体（水、油或表面活性剂溶液）相比表现出增强的性能。讨论了微乳液有效地穿透固体结构的关键性质；发现微乳液的配方和由此产生的粘度对流体吸收量有决定性的影响。在微乳液浸渍后观察到细胞壁成分的溶解。因此，微乳液不仅可以有效地渗透空隙，还可以溶解疏水性和亲水性成分。预计本研究提出的概念将为纤维系统中的流体吸收开辟机会，用于生物质预处理，以及在多孔木质纤维素中输送亲水性或疏水性部分。
