http://orcid.org/0000-0001-6437-5942
![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
ABSTRACT
Particle coagulation, in conjunction with nucleation and growth, plays a significant role in determining the evolution of particle size distribution in emulsion polymerizations. Therefore, many modelling and experimental studies have been carried out to have a better understanding and control of the particle coagulation phenomenon in order to achieve high-quality as well as highly efficient industrial production. This article presents a review of modelling and experimental studies focused on the particle coagulation phenomenon in emulsion polymerizations. The state-of-art of particle coagulation modelling pertaining to emulsion polymerizations is discussed. Experimental studies concerned with latex coagulation processes are summarized next. The review finishes by discussing outstanding problems that need attention and sharing our perspectives on future developments.
Nomenclature
| F | = | external force, N |
| G | = | shear rate, 1/s |
| G | = | acceleration due to gravity, m/s2 |
| H | = | hydrodynamic interaction function between two particles |
| I | = | particle momentum of inertia, kg•mCitation2 |
| kB | = | Boltzmann constant, J/K |
| K‘g | = | constant |
| K”g | = | constant |
| K”o,K”p | = | numerical constant depending on the type of fluid motion |
| Ks, Kp | = | constant |
| l | = | distance away from particle surface, m |
| L | = | angular momentum, kg•m2/s |
| m | = | particle mass, kg |
| M | = | total torques acting on a particle, N•m |
| N | = | impeller agitation speed, rpm |
| P | = | power consumption, W |
| Pe | = | particle Peclet number |
| Pe' | = | modified particle Peclet number |
| r | = | radius of spherical particle, m |
| R | = | center-to-center separation, m |
| t | = | time, s |
| T | = | temperature, K |
| u | = | particle velocity, m/s |
| U | = | velocity component, m/s |
| V | = | total volume of liquid, m3 |
| VA | = | Van der Waals attractive potential energy, J |
| VD | = | depletion potential energy, J |
| Vint | = | total inter-particle interactions, J |
| VR | = | repulsive potential energy, J |
| VS | = | steric potential energy, J |
| Wij | = | stability ratio |
| = | time step, s |
Greek letters
| α | = | collision efficiency |
| β | = | coagulation kernel |
| ϵ | = | turbulent kinetic energy dissipation rate, m2/s3 |
| μ | = | dynamic viscosity, Pa·s |
| ν | = | kinetic viscosity, m2/s |
| γ | = | deformation rate, 1/s |
| κ | = | inverse double layer thickness, 1/m |
| = | solid volume fraction | |
| = | friction constant | |
| χ | = | emulsifier coverage, mol/m2 |
| Φ | = | viscous energy dissipation rate per unit volume for laminar flow |
| Γ | = | surfactant surface density, mol/m2 |
| ρ | = | density, kg/m3 |
| = | rotation rate of particle, rad/s |
Subscripts
| i, j, k | = | the ith, jth , kth particle |
| p | = | particle |
| x,y,z | = | radial, tangential or axial directions |
Abbreviations
| AA | = | acrylic acid |
| ABS | = | acrylonitrile-butadiene-styrene |
| Ac | = | acrylate |
| AcA | = | acrylamide |
| APS | = | ammonium persulfate |
| AIBN | = | azodiisobutyronitrile |
| BuA | = | butyl acrylate |
| C | = | coagulation |
| CFD | = | computational fluid dynamics |
| CMC | = | critical micelle concentration |
| DEM | = | discrete element method |
| DLVO | = | Derjaguin–Landau–Verwey–Overbeek (theory) |
| DMAEA | = | 2-dimethylamino-ethyl acrylate |
| EA | = | ethyl acrylate |
| EHA | = | 2-ethylhexyl acrylate |
| G | = | growth |
| KPS | = | potassium persulfate |
| MMA | = | methyl methacrylate |
| N | = | nucleation |
| NaPS | = | sodium persulfate |
| PBE | = | population balance equation |
| PSD | = | particle size distribution |
| Refs | = | references |
| SBc | = | sodium bicarbonate |
| SEMA | = | sulfoethyl methacrylate |
| Sty | = | Styrene |
| SFS | = | sodium formaldehyde sulphoxylate |
| tBHP | = | t-butyl hydrogen peroxide |
| VAc | = | vinyl acetate |
| VC | = | vinyl chloride |
| VDC | = | vinylidene chloride |
| VDF | = | vinylidene fluoride |
| VOC | = | volatile organic compounds |
Acknowledgments
We thank ANR for its financial support of project Scale-up (ANR-12-RMNP-0016).