Elastocapillary Dynamics During Wetting and Drying of Sheets and Fibers

1132835石材表面张力在许多工业问题和自然现象中起作用；其中许多涉及基本材料的显着弹性效应，例如周围基质和/或多孔基质，例如纺织品，头发和过滤器只是一些软材料，在潮湿或干燥时容易改变形状（和可能的功能）。尽管涉及表面张力（毛细作用）、弹性和可能的其他力之间相互作用的静态问题已经得到了很好的研究，但对弹性毛细作用的动力学研究却很少，而这正是本文的主题。由于应用范围涉及弹性毛细管动力学，跨越材料科学，生物和环境科学，我们相信这一研究领域将产生新的见解和应用。本提案的研究重点是在实验和理论上描述两种常见的几何形状-薄片和纤维-以及两种常见的动态情况-自发润湿和干燥。此外，我们将研究由纤维基质组成的模型软多孔材料的润湿和干燥动力学。通过这种方式，我们将对弹性毛细管流动问题的动力学进行系统而广泛的描述。本提案中描述的研究可能会产生新的见解，例如是否存在用于润湿纤维介质的最佳液滴大小以及纤维介质的干燥速率如何受到纤维的柔软度（弹性）的影响。更广泛的影响:除了在工程、物理和材料科学领域的期刊上发表我们的研究成果外，PI还将继续开展多方面的拓展活动，包括接待来自不同学科和教育机构的访客，让本科生参与研究并在会议上发表演讲，为本科生、研究生和博士后同事领导专业发展活动。并参与为来自代表性不足群体的年轻研究人员提供指导的项目。此外，在过去的9年里，PI成功地将研究主题融入了他为儿童和家长所做的“假日”讲座中，他将继续发展和呈现。总的来说，这项研究将对我们对常见软纤维材料的润湿和干燥的理解产生直接影响，这在各种工业和自然系统中都有出现。

1132835StoneSurface tension plays a role in many industrial problems and natural phenomena; many of these involve significant elastic effects of the basic materials such as the surrounding substrates and/or porous matrices, e.g. textiles, hair, and filters are just some of the soft materials that readily change shape (and possibly function) when wet or dried. Although static problems involving the interplay between surface tension (capillarity), elasticity, and possibly other forces are well studied, there are very few studies of the dynamics of elastocapillarity, which is the subject of this proposal. Because of the breadth of applications that involve elastocapillary dynamics, spanning material science, and the biological and environmental sciences, we believe that this research area will yield new insights and applications. The research in this proposal is focused on characterizing, both experimentally and theoretically, two common geometries - sheets and fibers - and two common dynamical situations - spontaneous wetting and drying. In addition, we will study the dynamics of wetting and drying of a model soft porous material consisting of a fibrous matrix. In this way, we will provide a systematic, yet broad characterization of the dynamics of elastocapillary flow problems. The research described in this proposal may yield new insights such as whether there is an optimum drop size for wetting a fibrous medium and how the drying rate of a fibrous medium is influenced by the softness (elasticity) of the fibers.Broader impacts: In addition to publishing our findings in journals that span engineering, physics, and materials science, the PI will continue his multi-faceted outreach activities, including hosting visitors from different disciplines and educational institutions, engaging undergraduate students in research and giving talks at conferences, leading professional development activities for undergraduate, graduate, and postdoctoral colleagues, and participating in mentoring programs for young researchers from under-represented groups. Also, the PI has successfully incorporated research themes into "holiday" lectures for children and parents that he has given over the past 9 years and which he will continue to develop and present. Overall, the research will have a direct impact on our understanding of wetting and drying of common soft fibrous materials, which arises in a wide variety of industrial and natural systems.