title: Cosolvents as Liquid Surfactants for Boron Nitride Nanosheet (BNNS) Dispersions.
abstract: Despite a range of promising applications, liquid-phase exfoliation of boron nitride nanosheets (BNNSs) is limited, both by low yield in common solvents as well as the disadvantages of using dissolved surfactants. One recently reported approach is the use of cosolvent systems to increase the as-obtained concentration of BNNS; the role of these solvents in aiding exfoliation and/or aiding colloidal stability of BNNSs is difficult to distinguish. In this paper, we have investigated the use of a t-butanol/water cosolvent to disperse BNNSs. We utilize solvent-exchange experiments to demonstrate that the t-butanol is in fact essential to colloidal stability; we then utilized molecular dynamics simulations to explore the mechanism of t-butanol/BNNS interactions. Taken together, the experimental and simulation results show that the key to the success of t-butanol (as compared to the other alcohols of higher or lower molecular weight) lies in its ability to act as a "liquid dispersant" which allows it to favorably interact with both water and BNNSs. Additionally, we show that the stable dispersions of BNNS in water/t-butanol systems may be freeze-dried to yield nonaggregated, redispersible BNNS powders, which would be useful in an array of industrial processes.
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Touseef
authors.initials: T
authors.lastname: Habib
authors.affiliation: Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, United States.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Sundaravadivelu Devarajan
authors.affiliation: Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, United States.
authors.forename: Fardin
authors.initials: F
authors.lastname: Khabaz
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Dorsa
authors.initials: D
authors.lastname: Parviz
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Achee
authors.affiliation: Department of Chemical Engineering, Texas Tech University , Lubbock, Texas 79409, United States.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Khare
authors.affiliation: Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States.
authors.forename: Micah J
authors.initials: MJ
authors.lastname: Green