title: Experimental and computational study of the effect of alcohols on the solution and adsorption properties of a nonionic symmetric triblock copolymer.
abstract: This study investigates the effect of alcohols on the solution and adsorption properties of symmetric triblock nonionic copolymers comprising blocks of ethylene oxide (EO) and propylene oxide (PO) (EO(37)PO(56)EO(37)). The cloud point, surface tension, critical micelle concentration (CMC), and maximum packing at the air-water interface are determined, and the latter is compared to the amount of polymer that adsorbs from solution onto polypropylene (PP) and cellulose surfaces. The interaction energy and radius of micelles are calculated by using molecular dynamics (MD) simulations. Equivalent MD bead parameters were used in dynamic density functional theory (DDFT) simulations to study the influence of alcohols on the phase behavior of EO(37)PO(56)EO(37) and its adsorption on PP from aqueous solutions. The simulation results agree qualitatively with the experimental observations. Ethanol acts as a good cosolvent for EO(37)PO(56)EO(37) and reduces the amount of EO(37)PO(56)EO(37) that adsorbs on PP surfaces; however, little or no influence is observed on the adsorption on cellulose. Interestingly, longer chain alcohols, such as 1-pentanol, produce the opposite effect. Overall, the solution and adsorption properties of nonionic symmetric triblock copolymers in the presence of alcohols are rationalized by changes in solvency and the hydrophobic effect.
authors.affiliation: Department of Forest Biomaterials, North Carolina State University, Raleigh, North Carolina 27695, USA.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.forename: Carlos
authors.initials: C
authors.lastname: Salas
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Pasquinelli
authors.forename: Jan
authors.initials: J
authors.lastname: Genzer
authors.forename: Orlando J
authors.initials: OJ
authors.lastname: Rojas
mesh_terms: D000327:Adsorption; D000438:Alcohols / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D003198:Computer Simulation; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D008958:Models, Molecular; D008968:Molecular Conformation; D011092:Polyethylene Glycols / Q000737:chemistry*; D011409:Propylene Glycols / Q000737:chemistry*; D012399:Rotation; D012996:Solutions; D055672:Static Electricity; D013500:Surface Tension
chemical_list: D000438:Alcohols; D008823:Micelles; C116176:PEO-PPO-PEO; D011409:Propylene Glycols; D012996:Solutions; D011092:Polyethylene Glycols; D002482:Cellulose