SmartNano

논문 초록 (Abstract)

Ultralight sponges with the ability to release protons on demand, namely, superhydrophobic melamine formaldehyde sponges (SHpho-MFSs), which are characterized as being safe-to-handle, convenient-to-use, easy-to-store, easy-to-carry, and easy-to-collect, are switched from superhydrophilic MFSs (SHphi-MFSs) by a one-step ultrasound treatment at a low pH. The wettability of the SHphi-MFS is completely switched from the outside to the inside of the MFS. After wettability switching is achieved, the SHpho-MFS that is prewetted with water and oil is able to selectively separate both water and oil, respectively. A compressed SHpho-MFS also exhibits excellent separation performance of a water-in-oil emulsion. Furthermore, since the SHpho-MFS can linearly release protons in an aqueous solution, during the oil/water separation (water-removing), an aqueous solution of a strong base is neutralized or changed into a certain solution with a tailored pH by a simple filtration step using an appropriately sized SHpho-MFS. The SHpho-MFS can maintain a slow reaction rate and reduce the sudden release of heat during neutralization. Controlled release of the SHpho-MFS capable of the ordered production of protons on demand is also achieved because the release “on and off” behavior of protons is repeatedly observed for every cycle.