Kinetics of Swelling of Cylindrical Temperature-Responsive Hydrogel: A Semi-Analytical Study

Cylindrical hydrogels have a wide variety of applications, especially in microfluidics as micro-valves, micro-mixers, and micro-lenses. Main advantages of them can be mentioned as their simple geometry and autonomous functionality due to their responses to the environmental stimuli. In current research, kinetics of swelling, shrinking and force generation of cylindrical temperature-responsive hydrogels have been investigated analytically. According to this, models of fluid permeation and large deformation of the hydrogels were considered and an analytical solution was performed. In order to study the behavior of the cylindrical hydrogels, the temperature is changed between higher and lower of the phase transition temperatures, and kinetics of the swelling and shrinking of the hydrogel have been studied and the distribution of stresses, stretches, water concentration and chemical potential are presented throughout the process. In addition, to investigate the behavior of the actuators, the cylindrical hydrogel is placed inside a hollow permeable pillar and the pressure of the hydrogel which puts on the pillar is studied. Ultimately, a comprehensive study on the effects of different parameters, namely, amount of temperature change, cross-link density and geometry, is conducted and the results are presented, which can be utilized in the design procedures of such actuators.

Download Full-text

Kinetics of cure, cross link density and adhesion of water-reactive alkoxysilicone sealants

Journal of Adhesion Science and Technology ◽

10.1163/156856102760146165 ◽

2002 ◽

Vol 16 (8) ◽

pp. 1055-1071 ◽

Cited By ~ 7

Author(s):

François De Buyl ◽

John Comyn ◽

Nick. E. Shephard ◽

Nagambal P. Subramaniam

Keyword(s):

Cross Link ◽

Link Density ◽

Cross Link Density ◽

Kinetics Of

Download Full-text

Ionic Liquids Applied to Improve the Dispersion of Coagent Particles in an Elastomer

Journal of Composites ◽

10.1155/2013/286534 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Magdalena Maciejewska ◽

Marian Zaborski

Keyword(s):

Ionic Liquids ◽

Alkyl Chain ◽

Cross Linking ◽

Cross Link ◽

Rubber Compounds ◽

Link Density ◽

Vulcanization Kinetics ◽

Cross Link Density ◽

The Cross ◽

Kinetics Of

The aim of this work was to study the activity of several ionic liquids (alkylimidazolium salts) that are used to improve the dispersion of coagent particles in peroxide-cross-linked hydrogenated acrylonitrile butadiene elastomer (HNBR). Hydrotalcite grafted with monoallyl maleate was applied as a coagent for the HNBR vulcanization. In this paper, we discuss the effect of the ionic liquids (alkylimidazolium salts) with respect to their anion (bromide, chloride, tetrafluoroborate, and hexafluorophosphate) and the length of alkyl chain in the cation (allyl-, ethyl-, butyl-, hexyl-, and octyl-) on the vulcanization kinetics of rubber compounds. The influence of ionic liquids on the cross-link density, the mechanical properties of the vulcanizates, and their resistance to weather ageing were also studied. Alkylimidazolium salts seem to improve the dispersion of the coagent particles and to be active in the cross-linking of HNBR with peroxide. The type of ionic liquid considerably influences the activity of the coagent particles toward the HNBR. The application of ionic liquids increases the cross-link density of the vulcanizates and improves their resistance to weather aging.

Download Full-text

Growth Kinetics of Quantum Size ZnO Particles

MRS Proceedings ◽

10.1557/proc-536-347 ◽

1998 ◽

Vol 536 ◽

Author(s):

E. M. Wong ◽

J. E. Bonevich ◽

P. C. Searson

Keyword(s):

Growth Kinetics ◽

Ostwald Ripening ◽

Chemical Potential ◽

Colloidal Suspensions ◽

Green Emission ◽

Blue Shift ◽

Constant Current ◽

Mass Model ◽

Zno Particles ◽

Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

Download Full-text

Boron nitride for modification of rubber based on isoprene elastomer

Voprosy Materialovedeniya ◽

10.22349/1994-6716-2019-100-4-105-112 ◽

2020 ◽

pp. 105-112

Author(s):

K. S. Zhansakova ◽

E. N. Eremin ◽

G. S. Russkikh ◽

O. V. Kropotin

Keyword(s):

Mechanical Properties ◽

Boron Nitride ◽

Gradual Increase ◽

Physical And Mechanical Properties ◽

Curing Time ◽

Cross Link ◽

Start Time ◽

Link Density ◽

Cross Link Density ◽

Isoprene Rubber

The work studies vulcanization characteristics of elastomers based on isoprene rubber filled with carbon black N330 and boron nitride (BN). The influence of the boron nitride (BN) concentration on technological, dynamic, physical and mechanical properties of elastomers has been researched. The application of boron nitride for producing rubber with good properties has been considered. With a gradual increase of the inert filler BN concentration up to 35%, a decrease in the curing rate by 33% and polymer cross-link density by 26% is observed. Moreover, the start time of vulcanization increases by almost 300%, the optimal curing time by 200%.

Download Full-text

Kinetic modelling of NO heterogeneous radiation-catalytic oxidation on the TiO2 surface in humid air under the electron beam irradiation

Nukleonika ◽

10.1515/nuka-2017-0034 ◽

2017 ◽

Vol 62 (3) ◽

pp. 235-240 ◽

Cited By ~ 2

Author(s):

Henrietta Nichipor ◽

Yongxia Sun ◽

Andrzej G. Chmielewski

Keyword(s):

Electron Beam ◽

Catalytic Oxidation ◽

Removal Efficiency ◽

Electron Beam Irradiation ◽

Kinetic Modelling ◽

Water Concentration ◽

Beam Irradiation ◽

Humid Air ◽

Kinetics Of ◽

Influential Parameters

Abstract Theoretical study of NOx removal from humid air by a hybrid system (catalyst combined with electron beam) was carried out. The purpose of this work is to study the possibility to decrease energy consumption for NOx removal. The kinetics of radiation catalytic oxidation of NO on the catalyst TiO2 surface under electron beam irradiation was elaborated. Program Scilab 5.3.0 was used for numerical simulations. Influential parameters such as inlet NO concentration, dose, gas fl ow rate, water concentration and catalyst contents that can affect NOx removal efficiency were studied. The results of calculation show that the removal efficiency of NOx might be increased by 8-16% with the presence of a catalyst in the gas irradiated field.

Download Full-text