Modeling deformation and contacts of pH sensitive hydrogels for microfluidic flow control

He, Tao; Li, Meie; Zhou, Jinxiong

doi:10.1039/c2sm06749h

Cited by 33 publications

(20 citation statements)

References 25 publications

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“…We study the deformation process of such an application using the FE model presently developed. In this example, we investigate a hybrid hydrogelmembrane microfluidic valve (He et al, 2012;Moore et al, 2000), where a membrane in contact with a hydrogel is used to control flow across an orifice located directly below center of the gel, see Fig. 10.…”

Section: Application In Microvalvesmentioning

confidence: 99%

Mechanics of inhomogeneous large deformation of photo-thermal sensitive hydrogels

Toh

et al. 2014

International Journal of Solids and Structures

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a b s t r a c tA polymer network can imbibe copious amounts of solvent and swell, the resulting state is known as a gel. Depending on its constituents, a gel is able to deform under the influence of various external stimuli, such as temperature, pH-value and light. In this work, we investigate the photo-thermal mechanics of deformation of temperature sensitive hydrogels impregnated with light-absorbing nano-particles. The field theory of photo-thermal sensitive gels is developed by incorporating effects of photochemical heating into the thermodynamic theory of neutral and temperature sensitive hydrogels. This is achieved by considering the equilibrium thermodynamics of a swelling gel through a variational approach. The phase transition phenomenon of these gels, and the factors affecting their deformations, are studied. To facilitate the simulation of large inhomogeneous deformations subjected to geometrical constraints, a finite element model is developed using a user-defined subroutine in ABAQUS, and by modeling the gel as a hyperelastic material. This numerical approach is validated through case studies involving gels undergoing phase coexistence and buckling when exposed to irradiation of varying intensities, and as a microvalve in microfluidic application.

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Section: Application In Microvalvesmentioning

confidence: 99%

Mechanics of inhomogeneous large deformation of photo-thermal sensitive hydrogels

Toh

et al. 2014

International Journal of Solids and Structures

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“…[1][2][3][4][5][6][7][8] Although some research groups have suggested that activated carbon/photocatalyst composites could be used as carriers to reuse nanoparticles, these composites prevent the irradiation of UV light to TiO 2 , and result in lower photocatalytic activity. 14,15 These template methods are complicated and may involve long process time. Among the promising candidate materials, hydrogels are attractive due to their highly absorbent properties, which are dependent on external environmental conditions, 9,10 and light-transparency in aqueous solution.…”

Section: Introductionmentioning

confidence: 99%

A facile template-free synthesis of pH-responsive polyelectrolyte/amorphous TiO₂ composite hollow microcapsules for photocatalysis

et al. 2015

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This paper presents a novel, facile method for fabricating pH-responsive inorganic/organic composite microspheres with hollow structures in the absence of a step for the removal of the core. Using polyelectrolyte (hydrogel) hollow microspheres without a need for further calcination and chemical etching, minimally cross-linked poly(methacrylic acid/ethylene glycol dimethacrylate/3-(trimethoxysilyl) propylmethacrylate), poly(MAA/EGDMA/TMSPM) [pMET] microspheres were prepared by a distillationprecipitation method. Once the pMET microspheres disperse in 2-propanol, the hollow structure is clearly observed and can be maintained more rigidly in a dry state after amorphous TiO 2 (a-TiO 2 ) is incorporated into the shell of a microsphere by a sol-gel method. The a-TiO 2 -incorporated pHresponsive pMET composite [pMET/TiO 2 ] hollow microspheres were tested as a photocatalyst in acidic and neutral conditions. The photocatalytic performance of the hollow pMET/TiO 2 composite microcapsules under neutral condition was better than that under acidic conditions due to their large active surface and strong adsorption ability against methylene blue (MB). † Electronic supplementary information (ESI) available: SEM images of poly(MAA/EGDMA) microspheres; OM images of poly(MAA/EGDMA) microspheres dispersed in 2-propanol and water; XRD pattern of pMET/a-TiO 2 composite microcapsules; additional schematic illustration; thermodegradation and photodegradation of MB without photocatalysts; FT-IR spectra of all samples. See Scheme 1 Schematic illustration for the synthetic process of poly-(MAA/EGDMA/TMSPM)/a-TiO 2 composite microcapsules: CLSM image of the poly(MAA/EGDMA/TMSPM) microspheres dispersed (a) in aqueous solution and (b) 2-propanol, and (c) EDX-maps of (green) titanium and (red) carbon from the hollow poly(MAA/EGDMA/ TMSPM)/a-TiO 2 composite microcapsules. 59258 | RSC Adv., 2015, 5, 59257-59262 This journal is

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“…Current studies on simulating pH-sensitive gel microfluidic valves are focused on the equilibrium state of inhomogeneous swelling of the gel (He et al, 2012;Zhang et al, 2012), and thus do not consider how the gel changes with the evolution of time during the entire process of swelling.…”

Section: Numerical Examples For Ph-sensitive Hydrogel Kineticsmentioning

confidence: 99%

“…We study the deformation process of such an application using the finite element model presently developed. In this example, we will investigate a hybrid hydrogelmembrane microfluidic valve (He et al, 2012;Moore et al, 2000), where a membrane in contact with a hydrogel is used to control flow across an orifice located directly below center of the gel, see Figure 3-14. In this application of the photo-thermal gel, the gel is initially not exposed to irradiation, and the gel is in a swollen state which prevents fluid flow across the orifice.…”

Section: Numerical Examples For Equilibrium Swelling Of Photothermal mentioning

confidence: 99%

“…This configuration has been studied extensively (He et al, 2012;Moore et al, 2000). However, contrary to what most studies propose, where the valve is commonly unblocked and swelling of the gel causes flow to be impeded in the valve, we propose the opposite mechanism, which utilizes the magnetic field dependence properties of the gel.…”

Section: Numerical Examples For Equilibrium Swelling Of Magneto-thermmentioning

Modeling deformation and contacts of pH sensitive hydrogels for microfluidic flow control

Cited by 33 publications

References 25 publications

Mechanics of inhomogeneous large deformation of photo-thermal sensitive hydrogels

Mechanics of inhomogeneous large deformation of photo-thermal sensitive hydrogels

A facile template-free synthesis of pH-responsive polyelectrolyte/amorphous TiO₂ composite hollow microcapsules for photocatalysis

Mechanics of hydrogels : a modeling and simulation approach

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Modeling deformation and contacts of pH sensitive hydrogels for microfluidic flow control

Cited by 33 publications

References 25 publications

Mechanics of inhomogeneous large deformation of photo-thermal sensitive hydrogels

Mechanics of inhomogeneous large deformation of photo-thermal sensitive hydrogels

A facile template-free synthesis of pH-responsive polyelectrolyte/amorphous TiO2 composite hollow microcapsules for photocatalysis

Mechanics of hydrogels : a modeling and simulation approach

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A facile template-free synthesis of pH-responsive polyelectrolyte/amorphous TiO₂ composite hollow microcapsules for photocatalysis