A study of the kinetics of swelling in cylindrical polystyrene gels: Mechanical behavior and final properties after swelling

1994 ◽  
Vol 101 (10) ◽  
pp. 9054-9059 ◽  
Author(s):  
Abdelkrim Hakiki ◽  
Jean E. Herz
1983 ◽  
Vol 25 (7) ◽  
pp. 1668-1675 ◽  
Author(s):  
A.A. Tager ◽  
Yu.S. Bessonov ◽  
T.V. Ikanina ◽  
T.A. Rodionova ◽  
A.I. Suvorova ◽  
...  

2015 ◽  
Vol 18 (4) ◽  
pp. 162-169
Author(s):  
Thao Song Thanh Nguyen ◽  
Nhung Thi Tuyet Le

An experimental investigation into ratcheting strain and stress-strain hysteresis loop in stress-controlled cyclic tensile tests at room temperature was performed to determine the effect of loading frequency on the cyclic mechanical behavior of highdensity polyethylene (HDPE). It was found that frequencies ranging from 0.01 Hz up to 1 Hz mostly affects the accumulated strain over related time scales (i.e that of the cycle itself) and not over long time scale (i.e. during the full test). In addition, the higher the frequency is, the more closed and vertical the loops are. Furthermore, the frequency affects only on the kinetics of stabilization of ratcheting strain but not on one of hysteresis loop.


2020 ◽  
Vol 12 (08) ◽  
pp. 2050090
Author(s):  
Amir Hossein Namdar ◽  
Hashem Mazaheri

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.


2016 ◽  
Vol 18 (12) ◽  
pp. 2088-2094 ◽  
Author(s):  
Andrea Carpinteri ◽  
Vittorio Di Cocco ◽  
Giovanni Fortese ◽  
Francesco Iacoviello ◽  
Stefano Natali ◽  
...  

Holzforschung ◽  
2015 ◽  
Vol 69 (9) ◽  
pp. 1059-1067 ◽  
Author(s):  
Hatem Abushammala ◽  
Jorge F. Pontes ◽  
Gustavo H. Gomes ◽  
Anayancy Osorio-Madrazo ◽  
Rossana M.S.M. Thiré ◽  
...  

Abstract To screen ionic liquid (IL) candidates for wood ionosolv pulping, swelling and viscoelastic studies on Norway spruce wood treated with ionic liquids have been conducted. In particular, the temperature dependency and kinetics of swelling in 1-butyl-3-methylimidazolium acesulfamate ([BMIM]Ace) and in 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) were in focus. The kinetics of volumetric swelling in [BMIM]Ace yielded an Ea of 54 kJ.mol-1 compared to 23 kJ.mol-1 in [EMIM]OAc. The viscoelastic behavior of IL-swollen wood was studied by dynamic mechanical analysis, and the lowest in situ glass transition temperature (Tg) of lignin was ∼58°C and ∼65°C in [BMIM]Ace and in [EMIM]OAc, respectively. These Tg values are lower than that found in water. Higher Tg was calculated by the Gordon-Taylor equation, which means that swelling is not only due to the plasticizing effect of the ILs. SEM images showed that [EMIM]OAc has a stronger plasticizing effect than [BMIM]Ace. Overall, [EMIM]OAc is the most efficient agent for wood swelling, softening, and disintegration and, thus, it is the most promising candidate for ionosolv pulping.


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