An official website of the United States government
Abstract Mineral dissolution in porous media coupled with single- and/or multi-phase flows is pervasive in natural and engineering systems. Dissolution modifies the physical, hydrological, and geochemical properties of the solid matrix, resulting in a complex coupling between local dissolution rate and pore-scale flow. The work reports a microfluidic approach that includes 2D reactive porous media and advanced pore flow diagnostics for the study of pore-scale dissolution in porous media with unprecedented details. The 2D microfluidic porous media, called micromodels, were fabricated in calcite by combining photolithography and wet etching, which not only offers precise control over the structural and chemical properties, but also facilitate unobstructed optical access to the pore flow, significantly improving over existing methods. We believe the work represents the first of its kind as it for the first time directly applies photolithography to calcite samples and demonstrates the use of particle image velocimetry to investigate chemical reactions in porous media. The preliminary results have revealed the crucial roles of local concentration gradients in mineral dissolution and call for reconsideration of many assumptions used in the current modeling tools, which paves the way for renewed fundamental understanding of reactive transport and improved modeling tools with better accuracy.
more »
« less
This content will become publicly available on June 4, 2026
3D Printing Reactive Porous Media: Calcite Precipitation Kinetics on Surface Functionalized Polymer Films and 3D-printed Cores
Mineral precipitation reactions in porous media can change the porosity and permeability of the rock formations. Predicting the rate of reaction and impacts on formation properties is challenging due to a lack of understanding of mineral precipitation reaction kinetics and mechanisms in porous media. This is furthermore challenging due to the highly heterogeneous nature of natural porous media. Here, we aim to develop a novel experimental platform leveraging 3D printing to facilitate replicable mineral precipitation experiments in controlled, heterogenous porous media systems. This requires fundamental understanding of the kinetics of mineral precipitation on the polymer materials used to fabricate the 3D printed porous media. In this work, we manipulate (via sulfonation) material surfaces (high impact polystyrene, HIPS) to promote calcite precipitation from supersaturated solutions to inform the design of synthetic subsurface systems. Calcite precipitation on HIPS films of varied surface sulfonation is confirmed using X-ray diffraction (XRD) analysis and weight-based precipitation experiments where increased precipitation with increased surface functionalization and solution saturation index are observed. This approach is then applied to 3D-printed porous media to enhance understanding of geochemical reactions, specifically calcite precipitation. Three dimensional images of Bentheimer Sandstone are used as the basis for 3D-printed porous media samples. Two 3D-printed samples were functionalized with acid to activate the surface and promote mineral precipitation. Functionalized and unfunctionalized samples underwent calcite precipitation core flooding experiments with oversaturated calcite solutions for 96 hours. Three dimensional X-ray micro-CT imaging revealed calcite growth in functionalized samples, with a calcite volume fraction of approximately 2.6% and a substantial reduction in porosity. Unfunctionalized samples exhibited diminished calcite precipitation and porosity changes. These findings demonstrate that reactive 3D-printed porous media can provide a versatile geochemical modeling and experimentation platform. Functionalizing 3D printed samples enhances reactivity, allowing investigations of mineral precipitation processes in complex porous media. This research highlights the potential for further exploration of 3D-printed media in various geochemical contexts.
more »
« less
- Award ID(s):
- 2025626
- PAR ID:
- 10643658
- Publisher / Repository:
- InterPore Journal
- Date Published:
- Journal Name:
- InterPore Journal
- Volume:
- 2
- Issue:
- 2
- ISSN:
- 3007-410X
- Page Range / eLocation ID:
- IPJ040625 to 7
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Numerical simulation is a commonly employed technique for studying carbon dioxide (CO2) storage processes in porous media, particularly saline aquifers. It enables the representation of diverse trapping mechanisms and the assessment of CO2 retention capacity within the subsurface. The intricate physicochemical phenomena involved necessitate the incorporation of multiphase flow, accurate depiction of fluid and rock properties, and their interactions. Among these factors, geochemical reaction rates and mechanisms are pivotal for successful CO2 trapping in carbonate reactive rocks. However, research on kinetic parameters and the influence of lithology on CO2 storage remains limited. This limitation is partly due to the challenges faced in laboratory experiments, where the time scale of the reactions and the lack of in situ conditions hinder accurate measurement of mineral reaction rates. This study employs proxy models constructed using response surfaces calibrated with simulation results to address uncertainties associated with geochemical reactions. Monte Carlo simulation is utilized to explore a broader range of parameters and identify influential factors affecting CO2 mineralization. The findings indicate that an open database containing kinetic parameters can support uncertainty assessment. Additionally, the proxy models effectively represent objective functions related to CO2 injectivity and mineralization, with calcite dissolution playing a predominant role. pH, calcite concentration, and CO2 injection rate significantly impact dolomite precipitation, while quartz content remains unaffected.more » « less
-
Abstract One of the most fundamental characteristics of a biomaterial tailored for bone repair and regeneration is its ability to promote bone regeneration and healing of large defects. This work reports producing a functionalized and hieratically porous bone scaffold that significantly supports cell adhesion and proliferation by providing bone mimicry structure and controlled release of protein. The Slit Guidance Ligand 3 (SLIT3) protein was previously tested to promote bone formation and control the resorption process in natural bone healing. In this study, our goal was to design a nanocomposite bone scaffold to be functionalized with SLIT3 protein and then evaluate the uptake and release profile from surface into culture media to support bone marrow-derived mesenchymal stem cells (MSC) 3D culture. Indirect 3D printing of a polylactic-co-glycolic acid (PLGA), hydroxyapatite nanoparticles, and polydopamine coated (PLGA-HANPs-PDA) was utilized to obtain a hierarchically porous and SLIT3 protein-releasing scaffold. The produced scaffold was evaluated and optimized using chemical, architectural, mechanical, and biological characterization techniques. Optimal physicochemical properties resulted in a unique microstructure with an average pore size of 178.06 ± 45 µm, 63% porosity, and stable and homogenous chemical composition. Mechanical testing demonstrated a compression strength up to 1.5 MPa at 75% strain, with a compression modulus of 0.58 ± 0.05 MPa. Preliminary biological experiments showed that the scaffold exhibited gradual SLIT3 protein release, biodegradability, and reliable biocompatibility for MSC cell culture. Finally, we showed for first time the bioactivity of SLIT3 protein within PLGA-HANPs-PDA scaffold to promote attachment and growth of mesenchymal stem cell (MSCs) seeded in bone mimicry scaffold matrix. The collected findings will serve as a bedrock for thorough and targeted in vitro studies to evaluate anticipated osteogenesis the MSCs.more » « less
-
Abstract The macro-porous ceramics has promising durability and thermal insulation performance. As porous ceramics find more and more applications across many industries, a cost-effective and scalable additive manufacturing technique for fabricating macro-porous ceramics is highly desirable. Herein, we reported a facile additive manufacturing approach to fabricate porous ceramics and control the printed porosity. Several printable ceramic inks were prepared, and the foaming agent was added to generate gaseous bubbles in the ink, followed by the direct ink writing and the ambient-pressure and room-temperature drying to create the three-dimensional geometries. A set of experimental studies were performed to optimize the printing quality. The results revealed the optimal process parameters for printing the foamed ceramic ink with a high spatial resolution and fine surface quality. Varying the concentration of the foaming agent enables the controllability of the structural porosity. The maximum porosity can reach 85%, with a crack-free internal porous structure. The tensile tests showed that the printed macro-porous ceramics possessed enhanced durability with the addition of fiber. With a high-fidelity three-dimensional (3D) printing process and the precise controllability of the porosity, we showed that the printed samples exhibited a remarkably low thermal conductivity and durable mechanical strength.more » « less
-
Abstract The macro-porous ceramics has promising durability and thermal insulation performances. A cost-effective and scalable additive manufacturing technique for the fabrication of macro-porous ceramics, with a facile approach to control the printed porosity is reported in the paper. Several ceramic inks were prepared, the foaming agent was used to generate gaseous bubbles in the ink, followed by the direct ink writing and the ambient-pressure and room-temperature drying to create the three-dimensional geometries. The experimental studies were performed to optimize the printing quality. A set of studies revealed the optimal printing process parameters for printing the foamed ceramic ink with a high spatial resolution and fine surface quality. Varying the concentration of the foaming agent enabled the controllability of the structural porosity. The maximum porosity can reach 85%, with a crack-free internal porous structure. The tensile tests showed that the printed macro-porous ceramics have enhanced durability with the addition of fiber. With a high-fidelity 3D printing process and precise control of the porosity, the printed samples exhibited a low thermal conductivity and high mechanical strength.more » « less
