Low cost and scalable method for modifying surfaces of hollow particles from hydrophilic to hydrophobic

Abstract

A low cost strategy is developed for hydrophobization of hollow silica particles without compromising with their structural integrity.

A lightweight thermally insulating and moisture-stable composite made of hollow silica particles

“…The composite sample was flipped every 30 m to ensure that each side was uniformly coated. 30 Fig. 1 shows the different steps of the hydrophobization process.…”

“…HSPs with an average diameter of 300 nm were synthesized by using a previously reported method (details ESI †). 30,32 CFs (diameter: 50-100 nm; 3% solid content, from University of Maine Process Development Center) were mixed in water (4 mg mL À1 ) by homogenizing with a homogenizer (IKA-T18 digital Ultra Turrax) at 15 000 rpm for 8 h before mixing with HSPs. HSPs and a CF-based composite was prepared by mixing 80 wt% HSPs with 19.5 wt% CF in water.…”

“…, calcium carbonate, carbon, hydroxy apatite) particles, and bacteria as templates or by etching the solid silica particles. 14–31 We recently demonstrated that HSPs can be synthesized very inexpensively by recycling the solvents. 32 HSPs can provide very high thermal insulation at a lower cost; however, because HSPs are a powder that is usually in the nano-micrometer size range, they are a health hazard, difficult to handle and transport, and can be messy to use.…”

“…[14][15][16][17][18][19] HSPs can be synthesized by several strategies, such as by using polymer reverse microemulsions, micelles, polymer (e.g., polystyrene [PS]) particles, inorganic (e.g., calcium carbonate, carbon, hydroxy apatite) particles, and bacteria as templates or by etching the solid silica particles. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] We recently demonstrated that HSPs can be synthesized very inexpensively by recycling the solvents. 32 HSPs can provide very high thermal insulation at a lower cost; however, because HSPs are a powder that is usually in the nano-micrometer size range, they are a health hazard, difficult to handle and transport, and can be messy to use.…”

Hollow Silica Particles: A Novel Strategy for Cost Reduction

“…Hollow silica particles can be synthesized by several methods, such as by using polymer micelles, reverse microemulsions, inorganic (e.g., calcium carbonate, carbon, hydroxy apatite) particles, polymer (e.g., polystyrene; PS) particles, and bacteria as templates [ 22 , 23 , 24 , 25 , 26 , 27 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. Similarly, some other unconventional methods, including etching of solid silica particles and spray drying a solution of solid silica particles, have also been explored [ 50 , 51 , 52 , 53 ].…”