Ion gels formed with ABA triblock polymers and ionic liquids (IL) have recently attracted significant attention. Because of their high ionic conductivity, high capacitance, and good mechanical integrity, ion gels prepared from triblock polymers of polystyrene-b-poly(methyl methacrylate)-b-polystyrene (SMS) and polystyrene-b-poly-(ethylene oxide)-b-polystyrene (SOS) and an IL 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide ([EMI][TFSI]) have been successfully applied as the dielectric layer in thin film transistors. However, water absorption can negatively affect the stability of the dielectric layer and lead to electrical breakdown. Consequently, the preferred polymer of these two is SMS. However, the high glass transition temperature (T g ) of PMMA limits the usable SMS polymer concentration in order to ensure comparable ionic conductivity to that of SOS ion gel; this constraint limits the modulus of the gel to about 10 3 Pa. In this work, we developed a new ABA triblock ion gel system using poly(ethyl acrylate) (PEA) as a low T g and hydrophobic midblock. The low T g of the midblock ensures the ionic conductivity of the resulting ion gels is comparable to that of SOS ion gels at polymer concentrations up to 50 wt %, which is a significant improvement relative to the currently used SMS ion gels. Additionally, by decreasing the size of the midblock at constant polymer concentration, the modulus and ionic conductivity of the ion gels increase synergistically. This interesting and counterintuitive effect reflects the concurrent increase in the number density and chain stretching of midblocks, accompanied by a net reduction in midblock concentration within the conducting phase. We demonstrate that electrolyte gated transistors (EGTs) made with SEAS ion gels have improved stability under ambient humid conditions in comparison to those made with SOS ion gels.

A facile, high-resolution patterning process is introduced for fabrication of electrolyte-gated transistors (EGTs) and circuits using a photo-crosslinkable ion gel and stencil-based screen printing. The photo-crosslinkable gel is based on a triblock copolymer incorporating UV-sensitive terminal azide functionality and a common ionic liquid. Using this material in conjunction with conventional photolithography and stenciling techniques, well-defined 0.5-1 µm thick ion gel films are patterned on semiconductor channels as narrow as 10 µm. The resulting n-type ZnO EGTs display high electron mobility (>2 cm 2 Vs −1 ) and on/off current ratios (>10 5 ). Further, EGT-based inverters exhibit static gains >23 at supply voltages below 3 V, and five-stage EGT ring oscillator circuits display dynamic propagation delays of 50 µs per stage. In general, the screen printing and photo-crosslinking strategy provides a clean room-compatible method to fabricate EGT circuits with improved sensitivity (gain) and computational power (gain × oscillating frequency). Detailed device analysis indicates that significantly shorter delay times, of order 1 µs, can be obtained by improving the ion gel conductance.

We have designed printable, biocompatible, and degradable ion gels by combining a novel ABA triblock aliphatic polyester, poly(ε-decalactone)-b-poly(DL-lactide)-bpoly(ε-decalactone), and a low toxicity ionic liquid, 1-butyl-1methylpyrrolidinium bistrifluoromethanesulfonylimide ([P 14 ]-[TFSI]). Due to the favorable compatibility between amorphous poly(DL-lactide) and [P 14 ][TFSI] and the insolubility of the poly(ε-decalactone), the triblock polymer forms self-assembled micellar cross-links similar to thermoplastic elastomers, which ensures similar processing conditions and mechanical robustness during the fabrication of printed electrolyte-gated organic transistor devices. Additionally, the ester backbone in the polymer structure enables efficient hydrolytic degradation of these ion gels compared to those made previously using carbon-backbone polymers.

Diphenhydramine (DPH) has been used with ibuprofen (IBU) or naproxen (NAP) in combined therapies to provide better clinical efficacy as an analgesic and sleep aid. We discovered that DPH can form protic ionic liquids (PILs) with IBU and NAP, which opens the opportunity for a new delivery mode of these combination drugs. [DPH][IBU] and [DPH][NAP] PILs exhibit low ionicity, as confirmed by Fourier transform infrared and H NMR spectroscopy, and accompanied by low diffusivity, high viscosity, and poor ionic conductivity. Evaluation of pharmaceutical properties of the two PILs showed that these PILs, despite high solubility and good wettability, exhibited low dissolution rates, owing to the poor dispersion of the PIL drops and the resultant small surface area during dissolution. However, when loaded into a mesoporous carrier, the PIL-carrier composites exhibited improved dissolution rates along with excellent flow properties and easy handling. Oral capsules of both PILs were developed using such composites. Such capsule products exhibited acceptable drug release and bioavailability as demonstrated by a predictive artificial stomach-duodenum dissolution test.

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