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Hydrofluoroethers are shown to be benign solvents for a wide variety of organic electronic materials, even at extreme conditions such as boiling temperature (see figure). Coupled with fluorous functional materials they open new frontiers for “green” materials processing that can be readily adopted by industry.

The concept of chemical orthogonality has long been practiced in the field of inorganic semiconductor fabrication, where it is necessary to deposit and remove a layer of photoresist without damaging the underlying layers. However, these processes involving light sensitive polymers often damage organic materials, preventing the use of photolithography to pattern organic electronic devices. In this article we show that new photoresist materials that are orthogonal to organics allow the fabrication of complex devices, such as hybrid organic/inorganic circuitry and full-colour organic displays. The examples demonstrate that properly designed photoresists enable the fabrication of organic electronic devices using existing infrastructure. Results and discussionAs a first target, we fabricated top-contact OTFTs having channel lengths which are difficult to achieve with conventional

Two types of preformed alginate wet gels, one with a low (30−35%) and the other with a high (65−75%) content of glucuronic acid, were reacted with an aliphatic triisocyanate that was priorly allowed to diffuse in the pores. This reaction formed urethane groups on the surface of the alginate framework and also formed a polyurea (PUA) network connecting these urethane groups via respective reactions of the triisocyanate with alginate surface −OH groups or with gelation water remaining adsorbed on the inner surfaces of the wet gels. These processes formed a conformal nanothin film of PUA around the alginate network. After drying the wet gels with the supercritical fluid CO 2 , we obtained PUA/polyurethane-crosslinked alginate (X-alginate) aerogels. Although X-alginate aerogels are essentially copolymers, unlike all copolymers mentioned in previous literature reports, the relative topology of the alginate and the cross-linker is defined at the nanoscopic scale rather than at the molecular level. For the systematic study of X-alginate aerogels as a function of synthetic conditions, the experimental protocol was designed according to the central circumscribed rotatory design model using the alginate and the triisocyanate concentration as independent variables. Empirical models were derived for all relevant material properties by fitting experimental data to the two independent variables. The chemical identity of all samples was confirmed with attenuated total reflectance−Fourier transform infrared spectroscopy and solid-state 13 C and 15 N cross-polarization magic angle spinning NMR spectroscopy. The percentage of PUA uptake in X-alginate aerogels (58−98%) was calculated from skeletal density data. Scanning electron microscopy showed that all samples were nanofibrous, indicating that PUA coated conformally the skeletal network of both alginates, and the micromorphology remained the same as in the native (non-cross-linked) samples. X-alginate aerogels are mechanically strong materials, in contrast to their native counterparts, which are extremely weak mechanically. Compared to various organic aerogels from the literature, X-alginate aerogels can be as stiff as many other polymeric aerogels with 2 or 3 times higher densities. In addition, X-alginate aerogels are good candidates for sound insulation applications, as the speed of sound in most samples was estimated to be significantly lower than the speed of sound in dry air.

An acid-sensitive semiperfluoroalkyl resorcinarene was synthesized, and its lithographic properties were evaluated. Its solubility in segregated hydrofluoroether solvents enables the patterning of delicate organic electronic materials.

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A novel approach for photochemical definition of distinct, basic color, emission areas in thin polymeric films is introduced. Two-color, blue and green, fluorescence imaging is demonstrated using an amino diphenylhexatriene derivative that upon protonation shows sizable shifts in both absorbance and fluorescence spectra. Protons are generated photochemically in selected areas of the thin polymeric films containing the probe by a typical onium salt photoacid generator. Significant “flow” of transferred electronic energy from a typical aromatic polymer, epoxy novolac, to the mentioned dye was manifested permitting amplification and color tunability of fluorescent signals.