Laser-induced alteration of microstructural and microscopic transport properties in porous materials: Experiment, modeling and analysis

Highlights: • Microscopic changes are induced in the morphometric properties of Indiana limestone rock by using lasers. • Pulsed lasers induce a great increase in micro-porosity with greater pore-connectivity. • Nd:YAG Laser treatment enhances open porosity and pore-connectivity by 15% and 460%. • Pulsed lasers widen the separation range and reduce the separation thickness while CO₂ laser reduces the pore connectivity. • Results show that laser treatments enhance the microscopic fluid transport efficiency in porous materials. Porous materials are of great importance in various industrial applications. Microscopic modifications in the pore structures of these materials can change their functional behavior. We treat Indiana limestone by lasers to modify its pore structures microscopically. Microcomputed tomography (micro-CT) of the treated samples reveal that pulsed Nd:YAG laser with energy 330 mJ increases open porosity of limestone by 15% and almost doubles the total porosity. This laser increases the limestone pore connectivity by 460%. High power CO₂ laser increases the open porosity by 20% but it reduces the pore connectivity of limestone. Our findings show that pulsed laser beams induce high increase in porosity and connectivity. 3D pore scale modeling using Cascaded lattice Boltzmann method (CLBM) on a D₃Q₂₇ model shows that regions treated by pulsed Nd:YAG lasers exhibit enhanced fluid transport efficiency compared to untreated regions. The obtained results successfully demonstrate that lasers can be used to induce a well controlled heat transfer in porous materials directly enhancing their morphometric characteristics and microscopic fluid transport behavior.