Showing papers by "Pijush Ghosh published in 2020"
TL;DR: In this paper, the authors proposed a method for the self-assembly of monodispersed atomically precise monolayer-protected noble metal clusters (CASs) formed by self-assembling monodiscrete solids.
Abstract: Cluster-assembled solids (CASs) formed by the self-assembly of monodispersed atomically precise monolayer-protected noble metal clusters are attractive due to their collective properties. The physi...
15 citations
TL;DR: The development of a bilayer based actuator composed of a solvent responsive biodegradable polymer and temperature responsive pNipam and the underlying coupled diffusion-deformation interaction during folding and unfolding is incorporated in the reported finite element model.
Abstract: High performance thermoresponsive soft, controllable and reversible actuators are highly desirable for diverse applications. The practical implementation of the existing poly(N-isopropylacrylamide) (pNipam) based soft thermoresponsive actuators faces serious limitations due to their functional requirement of proximal bulk solvent medium. In this work, addressing this issue, we report the development of a bilayer based actuator composed of a solvent responsive biodegradable polymer and temperature responsive pNipam. The designed bilayer is capable of achieving reversible and irreversible actuation as needed when exposed to a physiological range of body temperature, without any solvent bath around. The solvent or water supplied by the pNipam layer at its lower critical solution temperature (LCST) builds a concentration gradient across the thickness of the polymer layer. The concentration gradient results in a strain gradient, causing an out-of-plane folding of the bilayer. The underlying coupled diffusion-deformation interaction during folding and unfolding is incorporated in the reported finite element model, capable of predicting actuation characteristics under different initial conditions. The combined experimental and modelling effort in this work highlights the possibility of engineering 2-dimensional films into complex 3-dimensional shapes, which could have potential applications in soft machines and robotics.
9 citations
5 citations
TL;DR: In this paper, a methodology has been proposed for prediction of glass transition temperature and Young's modulus of an inaccessible substrate in a bilayer system using nanoindentation experiments on poly-Methylmethacrylate (PMMA) coating.
4 citations
08 Dec 2020
TL;DR: In this article, the growth of stable TiO2 nanotube arrays on flexible Kapton substrates by electrochemical anodization of a sputtered Ti (titanium) film was reported.
Abstract: This work reports the growth of stable TiO2 nanotube arrays on flexible Kapton substrates by electrochemical anodization of a sputtered Ti (titanium) film. Although such nanotubes are conventionall...
3 citations
09 Mar 2020
TL;DR: In this article, the physical interaction and molecular mechanisms between functional groups of two different coating polymer (Epoxy and poly(methyl methacrylate) (PMMA)) and cement hydration products were studied using molecular dynamics simulation.
Abstract: Polymers are widely used for concrete coating applications such as surface coating materials for buildings, preventing penetration of water or air, aesthetic purpose like glazing finish, conservation materials for mural paintings and many more. In the field, the common practice is to coat concrete after it has set completely (28 days), but it is not well understood if this will maximize the interfacial strength. Hence there is a need to determine at what time after the addition of water, the coating should be applied and also how surface characteristics influence interfacial strength. The reason for better interfacial performance at the interface between coating polymers and cement paste is due to the physical and chemical interactions between the cement hydration products and the different functional groups in coating polymer. In the present work, the physical interaction and molecular mechanisms between functional groups of two different coating polymer (Epoxy and poly(methyl methacrylate) (PMMA)) and cement hydration products during early stages of cement hydration is studied using molecular dynamics simulation. The mechanical response and the physical interaction of functional groups of two different coating polymer Epoxy and PMMA are significantly influenced by (a) pore solution calcium (b) C–S–H substrate calcium and (c) adsorbed water layer.
1 citations