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Abstract The mechanism of separation methods, for example, liquid chromatography, is realized through rapid multiple adsorption‐desorption steps leading to the dynamic equilibrium state in a mixture of molecules with different partition coefficients. Sorting of colloidal particles, including protein complexes, cells, and viruses, is limited due to a high energy barrier, up to millions kT, required to detach particles from the interface, which is in dramatic contrast to a few kT for small molecules. Such a strong interaction renders particle adsorption quasi‐irreversible. The dynamic adsorption‐desorption equilibrium is approached very slowly, if ever attainable. This limitation is alleviated with a local oscillating repulsive mechanical force generated at the microstructured stimuli‐responsive polymer interface to switch between adsorption and mechanical‐force‐facilitated desorption of the particles. Such a dynamic regime enables the separation of colloidal mixtures based on the particle‐polymer interface affinity, and it could find use in research, diagnostics, and industrial‐scale label‐free sorting of highly asymmetric mixtures of colloids and cells.
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This content will become publicly available on December 4, 2025
Investigation of Dynamic Adsorption and Desorption of Polymer Nanogel in Porous Media through Microfluidics
Summary Understanding the transport and retention of elastic nanogel and microgel particles in porous media has been a significant research subject for decades, essential to the application of enhanced oil recovery (EOR). However, a lack of dynamic adsorption and desorption studies, in which the kinetics in porous media are seldom investigated, hinders the design and application of polymer nanogel in underground porous media. In this work, we visualized and quantified the transport and dynamic adsorption of polymer nanogel in 3D glass micromodels that were manufactured by packing glass beads in capillaries. Calibrating the linearity of fluorescence intensity to concentration, we calculated the adsorption kinetics at concentrations of 0.1 wt%, 0.2 wt%, and 0.3 wt% and flow rates of 0.01 mL/h, 0.02 mL/h, and 0.03 mL/h. In addition to time, concentration, and flow rate, the experimental results showed that dynamic adsorption is also a function of transport distance, which is due to the different adsorption abilities of particles. We also found that the uneven adsorption distribution can be attenuated by decreasing nanogel concentration or increasing flow rate. The work provides a new method to obtain adsorption and desorption kinetics and adsorption profile of submicron particles in porous media at flowing conditions through microfluidics.
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- Award ID(s):
- 2152609
- PAR ID:
- 10583442
- Publisher / Repository:
- Society of Petroleum Engineers
- Date Published:
- Journal Name:
- SPE Journal
- Volume:
- 30
- Issue:
- 01
- ISSN:
- 1086-055X
- Page Range / eLocation ID:
- 344 to 357
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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