Ultrathin Hydrophobic Inorganic Membranes via Femtosecond Laser Engraving for Efficient and Stable Extraction in a Microseparator

Abstract

Miniaturization of separators is essential owing to the enhanced surface area and reduced diffusion distance. It is difficult to realize membrane-based countercurrent extraction in the microscale as surface forces dominate over gravity forces and a considerable pressure drop perturbs pressure control. Here, we report a new route for continuous and high-yield extraction in microchannel membrane contactors using inorganic membranes with collective effects of femtosecond laser engraving and hydrophobic self-assembly, resulting in similar extraction efficiencies as organic membranes but with a much wider operating range and better durability, owing to their uniform pore size at 10 μm, hydrophobic feature, and model-guided pressure control. Compared to conventional devices, the lower flow capacity of the microseparator could be offset by reduction in "height equivalent to a theoretical plate", resulting in potential orders of magnitude reduction in device volume. The microseparator was then integrated with a microreactor for continuous synthesis and separation of a highly explosive chemical, methyl ethyl ketone peroxide, from which high extraction efficiencies were obtained with the final product meeting industrial standard. This work provides an attractive alternative, inorganic membranes, to organic membranes in microscale separation with improved stability and a wider operating range.

Reversible Bubble Transfer on a Bioinspired Tridirectionally Anisotropic Lubricant-Infused Surface

“…Rough structures are crucial for surface wettability, and nanoscale structures are demonstrated to be indispensable to stabilize the lubricants on SLIS. , Currently, various methods have been developed to construct micro/nanostructures on solid surface, such as hydrothermal, , photolithography, , spray coating, , pulsed laser ablation, , and so forth. Among them, femtosecond laser has the advantages of ultra-short pulse width and ultra-high peak intensity, enabling high precision processing of various materials (e.g., metals, semiconductors, and polymers), and are, therefore, widely used to machine diverse micro/nanostructures that are required by SLISs.…”