190 research outputs found
Ionic liquid–solid interface and applications in lubrication and energy storage
No full textInternational audienc
Potentiating Virus-like Particles for Mucosal Vaccination Using Material Science Approaches
No full textVirus-like particles (VLPs) exhibit such unique colloidal and structural properties that make them ideal candidates for various bio-nanotechnology applications, among which mucosal vaccination is particularly promising. However, since mucosal surfaces present harsh environments to VLPs, stabilization of VLP capsids or alternative delivery strategies are necessary. Addressing these challenges requires interdisciplinary research, and the intersection of material science and immunology is presented in this review. Approaches such as crosslinking capsid coat proteins, incorporating VLPs in polymer matrices and hydrogels, or forming crystalline nano-/micro-structures show potential for developing muco-stable VLP vaccines or for delivering these vaccines in a sustainable manner. This review explores recent material science approaches that leverage VLPs as nanotools for various applications and with the potential for translation to mucosal vaccination
Influence of ligand-receptor interactions on force-extension behavior within the freely jointed chain model
No full textWe study the influence of receptor-ligand interactions on the force response of single polymer chains theoretically. The extension of the chain is modeled in terms of freely jointed chain or elastic freely jointed chain (EFJC) models. The situation involving noninteracting bonds is solved exactly, while effects of interactions are treated within a mean-field approximation. The form with shorter bonds governs the low force situation, while the form with longer bonds is relevant in the high force regime. We further discuss the accuracy of approximate relations, which were used to describe the response of the EFJC model
Capillary wetting and interfacial phenomena in microstructures
No full textFluid penetration into capillary tubes resulting from the interplay between solid-liquid adhesive interactions and liquid-liquid cohesive interactions is a ubiquitous phenomenon. In nature, the rise of underground water in the soil is due to capillary pressure. Moreover, a wide variety of technological applications, e.g. oil extraction through porous rocks, washing process with detergents, surface coating etc, are based fundamentally on capillarity effects. As a result, studies with respect to the physics of capillary flows, both from the engineering and applied sciences and from a theoretical point of view, have been constantly renewed for almost a century.
In addition, carrier liquids containing nano-sized particles are termed as nanofluids that can result in novel thermophysical properties and thus are of practical importance. Many practical applications like underfill flow process in flip chip technology and spin coating involve flow of nanofluids driven by wetting forces. In addition, with the trend towards device miniaturization, cooling of microelectronics with the aid of surface tension driven nanofluid flow has become a potential application. Thus, characterization of the capillarity of nanofluids is essential for flow control purposes in those applications.
In order to better understand the physics involved in the motion of three-phase contact line over a solid surface, this thesis research primarily presents investigations on the capillarity of simple liquids in two novel configurations. Firstly, the capillary filling with the effect of pneumatic pressure of trapped air is studied. The novelty of this work is on the effect of air backpressure on the capillary flow; such a pressure is built up as a result of the air confined within the closed end of the capillary. Both the filling experiment and the theoretical prediction have been done and compared. Secondly, experiment and theoretical study on the capillary flow from a pendant droplet are performed. The effects of finite sized reservoir on the dynamics of flow are examined. The novelty of this work is on the effect of changes in pendant droplet surface area on the capillary flow, resulting in much faster displacement of the meniscus. Both systems studied herein are of practical importance in techniques employed in the field of microfluidics.
In continuance, surface tension and contact angle, spreading and capillarity of nanofluids are studied. For many years, the physics involved in the shape and contact angle of a droplet on a solid surface has received considerable attention and the physiochemical and physical-statistical parameters controlling surface wettability have been clarified for a long time. For nanofluids, however, there is a lack of systematic studies on the effect of nanoparticles concentration on surface tension, contact angle and wetting behavior. Presence of nano-sized particles within a very thin nanofluid film over the solid surface results in complex flow patterns and new phenomena. The results from the first-part of this thesis research can help to enhance our understanding of the physics involved in the capillarity of nanofluids. Both experiments and theoretical predictions have been conducted and compared.MASTER OF ENGINEERING (MAE
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