Spontaneous Dispersion of Particles in Liquid Surfaces

1236035 singh这项研究的目的是研究粒子吸附的物理性质和粒子与流体-流体界面接触时发生的粒子的自发分散。面粉、花粉等小颗粒的分散速度极快，特别是在像水这样的流动液体的表面上，简直就是爆炸性的。这种界面力驱动的粒子分散是很重要的，因为它会导致粒子在一个小区域上分散到一个大几个数量级的区域，几乎瞬间分散成一个单层。虽然韦伯数和邦德数以及接触角是控制粒子向界面法向运动的重要无量纲参数，但控制粒子横向运动的参数尚不完全清楚。我们的主要目标是：(i)利用实验和直接数值模拟来确定颗粒分散速度对重要参数的依赖性，并量化分散对包括微生物和病毒在内的小颗粒在液体表面上的传播速度的增强。（二）模拟亲水植物二维授粉过程的流体动力学。（iii）模拟导致团块在液体表面破碎和扩散的机制。知识价值。过去研究的重点是了解已经被困在流-液界面上的粒子相互作用的机制。拟议的研究将首次考虑突然分散的作用，这将提高我们对水面上发生的生物过程的理解，改进对小颗粒（包括微生物和病毒）在界面上传播的速率的估计，并改进制药和食品工业中涉及粉末在液体表面上的分解和传播的过程的建模。更广泛的影响。这项研究将与教育和推广充分结合，涉及研究生和本科生，特别是女性和少数族裔，在我们的大学课程中，在新泽西理工大学的研讨会中，以及为市中心大学预科学生提供的BBG教育计划中，协同活动，鼓励他们探索科学，技术，工程和数学（STEM）的职业生涯。这项工作将进一步提高我们理解和模拟吸附在气液和液液界面上的颗粒的作用的能力，这些颗粒在许多物理和生物过程中起着重要的作用，例如亲水植物的授粉，液体表面微生物和细菌的传播，以及流体-流体界面上单层的形成。该项目有可能为理解具有非生物二维授粉系统的植物进化机制的物理基础做出重大贡献。

1236035SinghThe aim of this research is to investigate the physics of particle adsorption and the spontaneous dispersion of particles that occurs when particles come in contact with a fluid-fluid interface. The dispersion of small particles, e.g., flour, pollen, etc., can occur so quickly that it appears explosive, especially on the surface of mobile liquids like water. This interfacial-force-driven dispersion of particles is important because it causes particles sprinkled over a small area to almost instantaneously disperse into a monolayer over an area that is several orders-of-magnitudes larger. While the Weber and Bond numbers, and the contact angle are the important dimensionless parameters that govern the motion of particles normal to the interface, it is not completely understood what parameters govern the lateral motions of the particles. Our main objectives are: (i) use experiments and direct numerical simulations to determine the dependence on important parameters of the speed at which particles disperse, and to quantify the enhancement resulting from dispersion in the rate of spreading on liquid surfaces of small particles including microbes and viruses. (ii) Model the fluid dynamics of the two-dimensional pollination process in hydrophilous plants. (iii) Model the mechanism that causes the breakup and spreading of agglomerates on liquid surfaces.Intellectual Merit. The focus of the past studies has been on understanding the mechanisms by which particles already trapped on fluid-liquid interfaces interact. The proposed study will, for the first time, consider the role of the sudden dispersion, which will improve our understanding of biological processes occurring over the surface of water, developing improved estimates for the rate at which small particles, including microbes and viruses, spread on interfaces, and improving the modeling of processes in the pharmaceutical and food industries that involve breakup and spreading of powders on liquid surfaces. Broader Impacts. This research will be fully integrated with education and outreach, involving graduate and undergraduate students, particularly women and under-represented minorities, with synergistic activities in our courses at the university, and in workshops in NJIT, and BBG educational programs for inner-city pre-college students to encourage then to explore careers in Science, Technology, Engineering and Mathematics (STEM).The proposed work will further our capability to understand and model the role of particles adsorbed at air-liquid and liquid-liquid interfaces which play an important role in many physical and biological processes, e.g., pollination of hydrophilous plants, the spread of microbes and germs on liquid surfaces, and formation of monolayers at fluid-fluid interfaces. This project has the potential to make a significant contribution to the understanding of the physics underlying the mechanisms that have evolved in plants that possess abiotic two-dimensional pollination systems.