Preparation of polyacrylamide derivatives showing thermo-reversible coacervate formation and their potential application to two-phase separation processes

Polymer ◽  
1996 ◽  
Vol 37 (4) ◽  
pp. 681-685 ◽  
Author(s):  
Hiroaki Miyazaki ◽  
Kazunori Kataoka
Keyword(s):  
Phase Separation ◽  
Potential Application ◽  
Two Phase ◽  
Separation Processes

scholarly journals Experimental and Numerical Investigation of Phase Separation due to Multi-Component Mixing at High-Pressure Conditions

2017 ◽  
Author(s):  
Christoph Traxinger ◽  
Hagen Müller ◽  
Michael Pfitzner ◽  
Steffen Baab ◽  
Grazia Lamanna ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Separation ◽  
Numerical Simulations ◽  
A Priori ◽  
Two Phase ◽  
Separation Processes ◽  
Pure Nitrogen ◽  
Elastic Light Scattering ◽  
Large Eddy ◽  
High Pressure Injection

Experiments and numerical simulations were carried out in order to contribute to a better understanding and predic-tion of high-pressure injection into a gaseous environment. Specifically, the focus was put on the phase separation processes of an initially supercritical fluid due to the interaction with its surrounding. N-hexane was injected into a chamber filled with pure nitrogen at 5 MPa and 293 K and three different test cases were selected such that they cover regimes in which the thermodynamic non-idealities, in particular the effects that stem from the potential phase separation, are significant. Simultaneous shadowgraphy and elastic light scattering experiments were conducted to capture both the flow structure as well as the phase separation. In addition, large-eddy simulations with a vapor- liquid equilibrium model were performed. Both experimental and numerical results show phase formation for the cases, where the a-priori calculation predicts two-phase flow. Moreover, qualitative characteristics of the formation process agree well between experiments and numerical simulations and the transition behaviour from a dense-gasto a spray-like jet was captured by both.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4756

Hierarchical Structuring in Block Copolymer Nanocomposites through Two Phase-Separation Processes Operating on Different Time Scales

2013 ◽  
Vol 23 (34) ◽  
pp. 4215-4226 ◽  
Author(s):  
Elina Ploshnik ◽  
Karol M. Langner ◽  
Amit Halevi ◽  
Meirav Ben-Lulu ◽  
Axel H. E. Müller ◽  
...  
Keyword(s):  
Phase Separation ◽  
Block Copolymer ◽  
Time Scales ◽  
Two Phase ◽  
Separation Processes ◽  
Hierarchical Structuring ◽  
Different Time Scales

scholarly journals Gelation Impairs Phase Separation and Small Molecule Migration in Polymer Mixtures

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1576
Author(s):  
Biswaroop Mukherjee ◽  
Buddhapriya Chakrabarti
Keyword(s):  
Phase Separation ◽  
Rational Design ◽  
Surface Segregation ◽  
Multiscale Methods ◽  
Coarse Grained ◽  
Polymer Gel ◽  
Polymer Mixtures ◽  
Separation Processes ◽  
Surface Migration ◽  
Wide Range

Surface segregation of the low molecular weight component of a polymeric mixture is a ubiquitous phenomenon that leads to degradation of industrial formulations. We report a simultaneous phase separation and surface migration phenomena in oligomer–polymer ( O P ) and oligomer–gel ( O G ) systems following a temperature quench that induces demixing of components. We compute equilibrium and time varying migrant (oligomer) density profiles and wetting layer thickness in these systems using coarse grained molecular dynamics (CGMD) and mesoscale hydrodynamics (MH) simulations. Such multiscale methods quantitatively describe the phenomena over a wide range of length and time scales. We show that surface migration in gel–oligomer systems is significantly reduced on account of network elasticity. Furthermore, the phase separation processes are significantly slowed in gels leading to the modification of the well known Lifshitz–Slyozov–Wagner (LSW) law ℓ ( τ ) ∼ τ 1 / 3 . Our work allows for rational design of polymer/gel–oligomer mixtures with predictable surface segregation characteristics that can be compared against experiments.

scholarly journals Structural and Viscoelastic Properties of Thermoplastic Polyurethanes Containing Mixed Soft Segments with Potential Application as Pressure Sensitive Adhesives

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3097
Author(s):  
Mónica Fuensanta ◽  
José Miguel Martín-Martínez
Keyword(s):  
Phase Separation ◽  
Potential Application ◽  
Viscoelastic Properties ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Pressure Sensitive Adhesives ◽  
Thermoplastic Polyurethanes ◽  
Pressure Sensitive ◽  
Soft Segments

Thermoplastic polyurethanes (TPUs) were synthetized with blends of poly(propylene glycol) (PPG) and poly(1,4-butylene adipate) (PAd) polyols, diphenylmethane-4,4′-diisocyanate (MDI) and 1,4-butanediol (BD) chain extender; different NCO/OH ratios were used. The structure and viscoelastic properties of the TPUs were assessed by infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, thermal gravimetric analysis and plate-plate rheology, and their pressure sensitive adhesion properties were assessed by probe tack and 180° peel tests. The incompatibility of the PPG and PAd soft segments and the segregation of the hard and soft segments determined the phase separation and the viscoelastic properties of the TPUs. On the other hand, the increase of the NCO/OH ratio improved the miscibility of the PPG and PAd soft segments and decreased the extent of phase separation. The temperatures of the cool crystallization and melting were lower and their enthalpies were higher in the TPU made with NCO/OH ratio of 1.20. The moduli of the TPUs increased by increasing the NCO/OH ratio, and the tack was higher by decreasing the NCO/OH ratio. In general, a good agreement between the predicted and experimental tack and 180° peel strength values was obtained, and the TPUs synthesized with PPG+PAd soft segments had potential application as pressure sensitive adhesives (PSAs).

Lipase purification using ionic liquids as adjuvants in aqueous two-phase systems

2015 ◽  
Vol 17 (5) ◽  
pp. 3026-3034 ◽  
Author(s):  
Ranyere L. Souza ◽  
Sónia P. M. Ventura ◽  
Cleide M. F. Soares ◽  
João A. P. Coutinho ◽  
Álvaro S. Lima
Keyword(s):  
Ionic Liquids ◽  
Environmentally Friendly ◽  
Two Phase ◽  
Separation Processes ◽  
High Purification ◽  
Aqueous Two Phase Systems ◽  
Phase Systems ◽  
Lipase Purification

Ionic liquids as adjuvant in aqueous two-phase systems (ATPS) are efficient, environmentally friendly, and “biocompatible” separation processes, which allow the high purification of enzymes.

Transmission Electron Microscopy (TEM) Observations of Phase-Separations of Gamma-Prime Precipitates in Ni-Al-Fe and Ni-Si-Fe Ternary Alloys

2007 ◽  
Vol 26-28 ◽  
pp. 1311-1314 ◽  
Author(s):  
M. Senga ◽  
H. Kumagai ◽  
Tomokazu Moritani ◽  
Minoru Doi
Keyword(s):  
Phase Separation ◽  
Volume Fraction ◽  
Heating Temperature ◽  
Ternary Alloys ◽  
Phase System ◽  
Precipitate Phase ◽  
Two Phase ◽  
Gamma Prime ◽  
Transmission Electron ◽  
The Difference

In Ni-13.0at%Si-3.1at%Fe alloy, when γ/γ’ two-phase microstructure formed at 1123 K is isothermally heated at 923 K which is lower than the temperature where the initial γ/γ’ microstructure forms, the phase-separation of γ/γ’ precipitate phase occurs and γ particles newly appear in each cuboidal γ’ precipitate. While in Ni-10.2at%Al-10.8at%Fe alloy, when γ/γ’ two-phase microstructure formed at 1023 K is isothermally heated at 1123 K which is higher than the temperature where the initial γ/γ’ microstructure forms, the phase-separation of γ’ precipitate phase takes place and γ particles newly appear in each cuboidal γ’ precipitate. Such appearance of new γ particles in γ’ precipitates can be explained by the difference in the volume fraction of γ phase that should exist in the γ/γ’ two-phase system depending on the heating temperature.

Study of the 90° Elbows Performance as Phase Separators in an Air-Water Two-Phase Flow

2003 ◽  
Author(s):  
Valente Herna´ndez P. ◽  
Florencio Sa´nchez S. ◽  
Miguel Toledo V. ◽  
Georgiy Polupan
Keyword(s):  
Phase Separation ◽  
Slug Flow ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Pressure Gradients ◽  
Two Phase ◽  
Branch Diameter ◽  
Independent Variables ◽  
Inclination Angles ◽  
Phase Separator

In order to observe the 90° elbows performance as phase separators in an air-water two-phase flow, experimental results for the phase split which occurs at a 90° branched elbow are presented. The branched elbow geometry was varied in order to have three (branch diameter / elbow diameter) ratios and three branch inclination angles. Also the pressure was monitored at different points of the elbow with ramification in order to examine the pressure drop effect. The flow pattern upstream was mainly slug flow. First, the analysis of the main independent variables effect, (superficial velocities, branch inclination angle, ratio of diameters and pressure gradients) was carried out, then a correlation for the phase split was developed and, finally a comparison was made with data of phase separation in T junctions obtained by Azzopardi [1] and Soliman [2], as a result, a better behavior as phase separator was found for the elbow.

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