Compatibility of poly(dimethylsiloxane) microfluidic systems with high viscosity hydrocarbons

Abstract

In this work, the compatibility of poly(dimethylsiloxane) (PDMS) with high viscosity petroleum liquids (bitumen) was evaluated to study the possibility of using PDMS microchannels in heavy oil and bitumen extraction research using solvent based methods such as Vapor Extraction. Three curing agent to base ratios (1:2, 1:10, and 1:20) were used to fabricate PDMS. Swelling ratio of these three samples in the vicinity of different organic solvents and diluted bitumen were evaluated by measuring the weight of sample every 15 min. It was found that 1:10 ratio PDMS was preferential ratio for minimizing absorption. We were particularly interested in the kinetic of swelling, deformation, and discoloration of PDMS. The hypothesis was that a PDMS microchip can still be used for experiments with heavy oil and bitumen if the experiment time is much shorter than the time it takes for PDMS discoloration, swelling, and deformation. The coating of PDMS slabs with trichloro (1 h 1 h 2 h 2 h-perfluorooctyl) silane was also tested and swelling ratios were again measured to evaluate the effect of surface coating. Swelling ratios were at the same order for uncoated PDMS which shows silane coating is not able to improve the solvent compatibility of PDMS. Moreover, solubility parameter was used to predict the swelling ratio of 1:10 PDMS sample in organic solvents. It predicts that hexane and toluene have the highest solubility that was in great agreement with experimental results. It seems that solubility parameter is a reliable factor to qualitatively predict the swelling ratio of PDMS. The effect of bitumen on transparency of PDMS was also studied using Ultraviolet-Visible spectrophotometer.

Pattern Formation in Evaporative Drying of a Polymer Solution Droplet over a Soft Swellable Substrate

“…The system despite its similarity with very well-known droplet evaporation over a rigid flat surface actually exhibits significantly distinct physics, where diffusive penetration of the solvent into the matrix and swelling of the substrate play an important, crucial role. The findings are also critically important in many systems, which include non-aqueous microfluidics, − understanding cell–matrix interaction over a bio-scaffold that may allow penetration of fluids, spray painting over plastic surfaces, and so on.…”

Surface acoustic wave-based generation and transfer of droplets onto wettable substrates

“…2d and e respectively), which are consistent with values reported in the literature. 61,62 The obtained PDMS surface is considered rigid since the elastocapillary number length 63,64 (g/E) , where g is the liquid surface tension and E is the Young's modulus of PDMS, 65 is considered to be low (z10 À8 m). To achieve hydrophobic surface, the spin-coated PDMS layer is cured at 180 C for 90 min, 66 and the WCA is measured to be 110 AE 0.3 (Fig.…”

Study on Epoxy Resin‐Modified Asphalt Binders with Improved Low‐Temperature Performance

“…e reason is that S is modified by silicone rubber. e calculated solubility parameter of silicone rubber is 7.65 (J/cm 3 ) 1/2 , while the solubility parameter of matrix binder is 15.68 (J/cm 3 ) 1/2 , and the large difference between the two leads to poor compatibility [23,24]. erefore, S will no longer be used in subsequent experiments.…”