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扮演着重要的角色；其中许多问题涉及基础材料的显著弹性效应，例如周围的基材和/或多孔基质，例如纺织品、头发和过滤器只是湿润或干燥时容易改变形状(和可能的功能)的软材料的一部分。虽然涉及表面张力(毛细)、弹性和可能的其他力之间相互作用的静态问题被很好地研究，但很少有关于弹性毛细的动力学的研究，这是本提议的主题。由于涉及弹性-毛细血管动力学、跨材料科学以及生物和环境科学的广泛应用，我们相信这一研究领域将产生新的见解和应用。该方案中的研究集中于从实验和理论上表征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--自发湿润和干燥。此外，我们还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，我们将提供弹性毛细管流动问题的动力学的系统而广泛的描述。这项建议中描述的研究可能会产生新的见解，如是否存在润湿纤维介质的最佳液滴尺寸，以及纤维介质的柔软(弹性)如何影响纤维介质的干燥速度。广泛影响：除了在跨越工程、物理和材料科学的期刊上发表我们的发现外，PI还将继续他的多方面外展活动，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，领导本科生、研究生和博士后同事的专业发展活动，以及参与代表不足群体的年轻研究人员的指导计划。此外，PI还成功地将研究主题融入到他过去9年来为孩子和家长举办的“节日”讲座中，并将继续发展和介绍这些主题。总体而言，这项研究将直接影响我们对常见软纤维材料的润湿和干燥的理解，这种材料存在于各种工业和自然系统中。

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.