Modeling dynamics of Polyacrylamide Gel in Oil-Water Mixtures: Dissipative Particle Dynamics Approach
- PDF / 1,423,454 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 15 Downloads / 163 Views
Modeling dynamics of Polyacrylamide Gel in OilWater Mixtures: Dissipative Particle Dynamics Approach Chandan K Choudhury, Olga Kuksenok* Materials Science and Engineering, Clemson University, Clemson, 29634, USA. *E-mail: [email protected]
ABSTRACT
Using dissipative particle dynamics approach, we model phase separation in a ternary system encompassing cross-linked polyacrylamide (PAM) gel, oil and water. PAM gels are widely used in many applications, from food and cosmetic applications to enhanced oil recovery approaches. We show that the PAM nanogel adsorbs at the oil-water interface and spreads out over this interface for the case of a loosely cross-linked polymer network. Tailoring PAM behavior at the oil-water interfaces by controlling gel’s properties could allow one to alter the properties of oil-water emulsions.
INTRODUCTION Polymer gel treatments play an important role in enhanced oil recovery (EOR) approaches. [1] EOR techniques are used to improve the efficiency of oil recovery, often by mobilizing heavy oils that could not be removed by the conventional recovery methods and water flooding. [1,2] Chemical flooding is often used to improve the oil recovery. The addition of polymers increases viscosity and decreases permeability of flooding water; tuning these parameters can reduce the mobility difference between the heavy oils and polymer solution, thereby reducing the fingering effects and increasing the oil sweep efficiency [2]. Water-in-oil emulsions are formed during drilling and multiple stages of production operations. [3] Thus an understanding of interactions of emulsions with polymers and gels used in EOR treatments is necessary for controlling and improving EOR processes. Polyacrylamide (PAM) polymers and gels are widely used in EOR approaches [4-6] due to low cost of acrylamide, robust polymerization approaches, and PAM aqueous solution properties. Herein, we develop a suitable Dissipative Particle Dynamics (DPD) framework for the PAM nanonogels placed into the oil-water mixtures and focus on the phase separation dynamics of oil-water mixtures containing these nanogels. MODELING PAM GELS IN OIL-WATER MIXTURES Within the dissipative particle dynamics (DPD) approach, clusters of
Downloaded from https://www.cambridge.org/core. HKUSTby Library, on 15 Jan 2018 at 09:44:39, subject to the Cambridge Core terms of use molecules or atoms are represented beads interacting via soft repulsive potential , available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/adv.2018.47
[7]; this soft repulsion potential allows one to use larger length and time scales compared to that in Molecular Dynamics (MD). Herein, we adapted DPD approach to simulate PAM gel network [8]. In this approach, we combine the features and parameters choices from the previously developed models for PAM chains in oilwater mixtures [9] and PNIPAAm gels [8]. The PAM gel forms a macroscopic network as a result of vinyl-divinyl radical polymerization. [10] The copolymerization of acrylamide with methylenebisacrylamide (MB
Data Loading...
