Ink-Jet Printing of High-Molecular-Weight Polymers in Oil-in-Water Emulsions

摘要

Ink-jet printing of high-molecular-weight polymers is inhibited by the extensional elasticity of the polymer chains. This article describes how emulsions can be used to print high-molecular-weight polymers at much higher concentrations than is possible in a binary solution. The polymers are dissolved in the dispersed phase of an oil-in water emulsion. The surface tension of the oil-water interface opposes deformation of the oil droplets during ejection from the nozzle and leads to the extensional strain occurring in the polymer-free continuous phase. We show that a solution of polystyrene (PS) (M-n = 419 kDa, polydispersity index = 1.21) can be printed at an overall concentration of 3.8 wt % in a sodium dodecyl sulfate-stabilized emulsion of methyl benzoate in water, an order of magnitude higher in concentration than previously reported for PS dissolved in binary solutions [Hoath, S. D.; Harlen, 0. G.; Hutchings, I. M. J. Rheol. 2012, 56 (5), 1109-1127]. Factors influencing the formulation of emulsions for ink -jet printing of polymers are discussed.