Electrostatic Formation of Liquid Marbles Using Thermo-responsive Polymer-coated Particles

Liquid marbles, floating droplets: preparations, properties, operations and applications

“…The common method to prepare LMs with composite functions is rolling droplets on a powder bed. 5,13,50,92,104,105 Except for the rolling approach, many researchers have proposed other ways to prepare LMs (see Table 2), such as electrostatic formation, 30,79,95,102,[106][107][108][109] selforganization by evaporation, 96,97 impacting hydrophobic powders, 77,103,110,111 self-assembly on a water surface, 16,18,50,98 inclined rolling method, 15,43,101,112 rotary centrifugation, 19 etc.…”

“…Recently, Kawata used PNIPAM@PS powder to form LMs via static electricity and the voltage power could reach 2.0 kV. 30 Kido prepared LMs with pH-responsive particles in two ways: rolling and the electrostatic method. They demonstrated that the powders from pH 3.0 solution are hydrophilic but from pH 10.0 solution are hydrophobic.…”

“…For example, liquids in LMs, such as water or blood, are more operable. 28 LMs can be driven or disassociated by external stimuli 29,30 and provide a cozier environment for an aerobe. 2,31 The particle shell ensures longer-time stability 24,[32][33][34][35] and stronger robustness of LMs because of the decreased evaporation rate.…”

Liquid Marbles under Electric Fields: New Capabilities for Non-wetting Droplet Manipulation and Beyond

“…Preparing LMs with water drops at 25 and 40 °C results in a smooth and rough LM surface, respectively, because PNIPAM@PS particles are hydrophilic and within the droplet at 25 °C but become hydrophobic and coat the water drop at 40 °C. 78 Owing to the wettability switch of PNIPAM affected by temperature, the prospect of using particles displaying low contact angles was explored, and LMs with diverse morphologies were prepared. Similar studies have also been performed on pH-responsive particles by drying latex particles under different conditions to cause a substantial disparity in their hydrophilic−hydrophobic balance and, consequently, their LM formation ability.…”

“…PNIPAM exhibits different hydrophobicity above or below its lower critical solution temperature, which is around 32 °C. Preparing LMs with water drops at 25 and 40 °C results in a smooth and rough LM surface, respectively, because PNIPAM@PS particles are hydrophilic and within the droplet at 25 °C but become hydrophobic and coat the water drop at 40 °C . Owing to the wettability switch of PNIPAM affected by temperature, the prospect of using particles displaying low contact angles was explored, and LMs with diverse morphologies were prepared.…”