The Spreading of Inkjet‐Printed Droplets with Varying Polymer Molar Mass on a Dry Solid Substrate

Abstract

An experimental study on the spreading of inkjet printed droplets of a polystyrene/toluene solution with varied molar masses on solid dry surfaces is presented. The polymer's number‐averaged molar mass was varied between 1.5 and 545 kDa, which also caused a variation in the viscosity from 0.6 to 1.7 mPa · s. The results were compared with theoretical models for droplet spreading and were found to fit with an error between 2 and 20% with the predictions. Furthermore, the in‐flight evaporation of the free‐falling droplet was investigated for polystyrene/toluene solutions that have a constant vapor pressure by printing from a systematically increased height.

Improvements in carbon fibre reinforced composites by inkjet printing of thermoplastic polymer patterns

“…The Oh of ink A and B was found to be 0.083 and 0.0284, respectively; this is in agreement with the theoretical predictions of Fromm [23] for a printable ink, however, it is not within the defined printable range of 0.1 < Oh < 1 [20]. However, other work [24,25] has also reported that inks outside of this region are printable, suggesting that this should not be a significant problem. The inks were deposited both on glass substrates (to determine the repeatability of the printed pattern), and onto carbon fibre reinforced Cycom 977-2 resin prepreg, in a hexagonal pattern (Fig.…”

Inkjet Printing—Process and Its Applications

“…[3] The drop then dries through solvent evaporation, [4] as shown in Figure 1. Recent studies [5] show that drop spreading and the final printed shape strongly depend on the viscosity, which in turn is a function of the molar mass of the polymer. More interestingly, the aforementioned group also found a printing height dependence of the final dried-drop diameter, which was a function of the polymer concentration.…”

“…Despite the difficulties in ensuring these conditions, all-printed transistors have been demonstrated using pentacene precursors and poly-4-vinylphenol (PVP) dielectric; [24] and polypyrrole and PVP-K60. [25] Additive printing of active layer inks (organic semiconductors dissolved in various solvents) such as poly [5,5 0 -bis(3-dodecyl-2-thienyl)-2, 2 0 -bithiophene] (PQT-12), [26] F8T2, [27] air-stable poly(3-hexylthiophene) (P3HT) derivatives, [28] 6,13-bis(triisopropylsilylethynyl) pentacene (TIPs pentacene), [29] other pentacene precursors and oligothophenes [30] have been demonstrated. Recently, carbon nanotubes (mobility $ 0.07 cm 2 V À1 s…”

Comparing membrane- and cantilever-based surface stress sensors for reproducibility

“…Numerous studies have been conducted to improve the control of the inkjet deposition of polymers [18,19]. For example, it was demonstrated that the coffee ring effect can be effectively decreased and even suppressed by mixing solvents of different surface tensions [20].…”