The Ludwig‐Soret Effect on the Thermally Induced Phase Separation Process in Polymer Solutions: A Computational Study

Kukadiya, Sureshkumar B.; Chan, Philip K.; Mehrvar, Mehrab

doi:10.1002/mats.200800074

Cited by 19 publications

(12 citation statements)

References 43 publications

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“…To date, most of the efforts have been limited to grafting contrast-enhancing agents to the surface of hydrophobic particles, where access to water is achievable or to enhance the delivery by and effective encapsulation. However, exploitation of the role of coacervation and the possibility of the Emulsion based Coacervation processes to boost T1 in combination with optical imaging has not been performed 37 38 . Our fundamental understanding of the Complex Coacervation Method is applied to the production of Hybrid Core-Shell NanoParticles (HyCoS NPs) made of a Chitosan-core and a Hyaluronic Acid-shell, and to the control of their properties for application in the MRI and Optical Imaging Field.…”

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confidence: 99%

Hybrid Core-Shell (HyCoS) Nanoparticles produced by Complex Coacervation for Multimodal Applications

Vecchione

Grimaldi

Forte

et al. 2017

Sci Rep

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Multimodal imaging probes can provide diagnostic information combining different imaging modalities. Nanoparticles (NPs) can contain two or more imaging tracers that allow several diagnostic techniques to be used simultaneously. In this work, a complex coacervation process to produce core-shell completely biocompatible polymeric nanoparticles (HyCoS) for multimodal imaging applications is described. Innovations on the traditional coacervation process are found in the control of the reaction temperature, allowing a speeding up of the reaction itself, and the production of a double-crosslinked system to improve the stability of the nanostructures in the presence of a clinically relevant contrast agent for MRI (Gd-DTPA). Through the control of the crosslinking behavior, an increase up to 6 times of the relaxometric properties of the Gd-DTPA is achieved. Furthermore, HyCoS can be loaded with a high amount of dye such as ATTO 633 or conjugated with a model dye such as FITC for in vivo optical imaging. The results show stable core-shell polymeric nanoparticles that can be used both for MRI and for optical applications allowing detection free from harmful radiation. Additionally, preliminary results about the possibility to trigger the release of a drug through a pH effect are reported.

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confidence: 99%

Hybrid Core-Shell (HyCoS) Nanoparticles produced by Complex Coacervation for Multimodal Applications

Vecchione

Grimaldi

Forte

et al. 2017

Sci Rep

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“…In his numerical investigation, the boundary that separates miscible and immiscible regions of polymer is shifted at different rates. Numerical study of spinodal decomposition under the influence of thermophoresis was done by Kukadiya et at [29]. As the thermophoresis, which directs the mass-flux by temperature gradient rather than random noise, and spinodal decomposition, which creates random structures by random fluctuation, compete with one another, when the quench is deep, the effect of spinodal decomposition hinders the effect of thermophoresis, though the rate of early stage is somewhat faster.…”

Section: Chapter 2 Literature Reviewmentioning

confidence: 99%

“…Here, it is time to also introduce a dimensionless term to account for thermophoresis. Suppose is the dimensionless diffusion coefficient which is independent of position, is driven by thermophoresis and is independent of Flory-Huggins' mechanism, it is commonly expressed as the following [29] [31] [30]:…”

Section: Governing Equations and Implementation 421 Governing Equations Assumptions And Non-dimensionlizationsmentioning

confidence: 99%

Computational study of comprehensive methods of initiating phase separation within metastable regions and obtaining some notable patterns in unstable region

Duc¹

2021

Preprint

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Binary phase polymer solution is interesting in that they expresses double-well local energy behavior, which means phase separation is preferred when condition is right. It is a feature that has been used to fabricate functional polymeric materials such as PDLC films for electro-optical devices (e.g. flat-panel displays and switchable windows). A uniformly mixed solution may be in one of three state: unstable, stable, or metastable. If the solution is unstable, then phase separation is spontaneous and proceeds by spinodal decomposition. If the solution is metastable, then the solution must overcome certain activation barrier for phase separation to proceed spontaneously. The activation barrier is usually the thermal noise or the fluctuation created by some external influence. This mechanism is called nucleation-and-growth. Manipulating morphology of phase separation has been of some great research interest because of its practical use. While spinodal decomposition has been well-studied, there are several other methods to further control morphology. For this thesis, the following methods are considered: double quench, anisotropic quenching with varying temperature or polymerization, surface-directed wetting, and concentration gradient. The methods are carried out within metastable or unstable regions or both. To numerically model, Cahn-Hilliard theory and FloryHuggins’ theory are used. This thesis is to also demonstrate that, present numerical method is very efficient and can work on complex geometry.

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“…The thermally induced phase separation process (TIPS) is one of the principal methods of producing numerous functional polymeric materials that are widely employed in industrial applications, such as membranes, microcellular foams, thermally reversible porous gels, and polymer-dispersed liquid crystals [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. During the TIPS process, the quality of the solvent decreases through an instantaneous quench in systems with an upper critical solution temperature (UCST) or an immediate jump in temperature in systems with a lower critical solution temperature (LCST) [ 4 , 9 , 10 , 11 , 12 , 13 , 14 ]. In systems with an UCST, a low-molecular-weight high boiling point solvent is initially mixed with a polymer at an elevated temperature to form a homogenous mixture [ 15 , 16 , 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Conductive Heat Transfer on the Morphology Formation in Polymer Solutions Undergoing Thermally Induced Phase Separation

Ranjbarrad

Chan

2022

Polymers

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Owing to the fact that heat transfer during the thermally induced phase separation process is limited, a quench rate is inevitably entailed, which leads to the existence of temporal and spatial variations in temperature. Hence, it is of great importance to take into account the nonisothermality during the phase separation process, especially in high viscosity polymer solutions. In this study, the influence of conductive heat transfer on the morphology formation during the thermally induced phase separation process was investigated theoretically in terms of quench depth, boundary conditions, and enthalpy of demixing to elucidate the interaction between temperature and concentration through incorporating the nonlinear Cahn-Hilliard equation and the Fourier heat transfer equation in two dimensions. The Flory-Huggins free energy theory for the thermodynamics of phase separation, slow mode theory, and Rouse law for polymer diffusion without entanglements were taken into account in the model development. The simulation results indicated a strong interaction between heat transfer and phase separation, which impacted the morphology formation significantly. Results confirmed that quench depth had an indispensable impact on phase separation in terms of higher characteristic frequency by increasing the driving force for heat transfer. Applying quench from various boundaries led to a difference in the quench rate due to the high viscosity of the polymer solution. This led to a gradation in pore size and anisotropic morphology formation. The degree and direction of anisotropy depended on quench depth and rate, quench time, heat conduction rate inside the solution, solution viscosity, temperature evolution, and the enthalpy of demixing. It was also verified that the influence of enthalpy of demixing on phase separation could not be neglected as it increased the solution temperature and led to phase separation being accomplished at a higher temperature than the initial quench temperature.

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The Ludwig‐Soret Effect on the Thermally Induced Phase Separation Process in Polymer Solutions: A Computational Study

Cited by 19 publications

References 43 publications

Hybrid Core-Shell (HyCoS) Nanoparticles produced by Complex Coacervation for Multimodal Applications

Hybrid Core-Shell (HyCoS) Nanoparticles produced by Complex Coacervation for Multimodal Applications

Computational study of comprehensive methods of initiating phase separation within metastable regions and obtaining some notable patterns in unstable region

The Effect of Conductive Heat Transfer on the Morphology Formation in Polymer Solutions Undergoing Thermally Induced Phase Separation

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