A solution-printing technique that enables the patterning and aligning of organic semiconducting crystals is necessary for their practical application. Here, we report the facile growth of 6,13-bis­(triisopropylsilylethynyl) pentacene (TIPS-PEN) semiconducting crystal patterns via a novel blade-coating technique. Defining low/high shearing-speed regions alternatively in a programmed manner enables the growth of TIPS-PEN crystals in low-speed regions and their patterning in high-speed regions. Various crystal-analysis tools, including polarized UV–vis absorption spectroscopy, grazing-incidence wide-angle X-ray scattering, and near-edge X-ray absorption fine structure, reveal that a crystal grown at an optimum shearing speed is highly oriented along the shearing direction with high crystallinity, and its molecules have a more edge-on orientation for efficient lateral-charge transport. As a result, organic field-effect transistors comprised of these crystals show a high field-effect mobility of up to 1.74 cm2/(V s). In addition, various crystal patterns can be created by simply changing the programming parameters, suggesting the broad utility of the crystal patterns and printing technique.

We developed a simple method for the fabrication of superhydrophobic surfaces on various substrates using spray coating. The fabrication method started with the blending of a modified hydrophobic siloxane binder, silica nanoparticles, and a volatile solvent by sonication. The mixture was spray-coated on various surfaces such as slide glass, paper, metal and fabric, forming a rough surface comprising silica particles dispersed in a hydrophobic binder. Surface hydrophobicity was affected by the surface energy of the binder and the degree of roughness. Therefore, we realized a superhydrophobic surface by controlling these two factors. The hydrophobicity of the siloxane binder was determined by the treatment of fluorine silane; the roughness was controlled by the amount of coated materials and sonication time. Thus, using the spray coating method, we obtained a superhydrophobic surface that was mechanically durable, thermally stable, and chemically resistant.

The cellular distribution of silica nanoparticles (NPs) in the liver is not well understood. Targeting specific cells is one of the most important issues in NP-based drug delivery to improve delivery efficacy. In this context, the present study analyzed the relative cellular distribution pattern of silica NPs in the liver, and the effect of surface energy modification on NPs. Hydrophobic NP surface modification enhanced NP delivery to the liver and liver sinusoid fFendothelial cells (LSECs). Conversely, hydrophilic NP surface modification was commensurate with targeting hepatic stellate cells (HSCs) rather than other cell types. There was no notable difference in NP delivery to Kupffer cells or hepatocytes, regardless of hydrophilic or hydrophobic NP surface modification, suggesting that both the targeting of hepatocytes and evasion of phagocytosis by Kupffer cells are not associated with surface energy modification of silica NPs. This study provides useful information to target specific cell types using silica NPs, as well as to understand the relationship between NP surface energy and the NP distribution pattern in the liver, thereby helping to establish strategies for cell targeting using various NPs.

To apply the solution-processed organic field-effect transistors (OFETs) to practical device manufacturing, there is a need for a processing technology capable of patterning organic semiconductors with high reproducibility and uniform shape in a large area. Herein, the facile, scalable strategy to fabricate poly­(3-hexylthiopehene-2,5-diyl) (P3HT) patterns through the flow-blade coating process. Controlling the stick–slip motion by the coffee-ring effect in low-/high-speed conditions induces the repetition of the advancing and receding of the contact line of the solution, which enables us to fabricate deposition of P3HT in low-speed regions and spacing in high-speed regions. Various surface-modified dielectrics with self-assembled monolayers (SAMs) influenced the morphological properties of patterned P3HT and indicated that the optimum condition for OFETs was achieved in alkyl-terminated SAM-treated cases. Additionally, various analysis tools including grazing-incidence wide-angle X-ray diffraction and near-edge X-ray absorption fine structure reveals that the flow-blade coating produces P3HT patterns with enhanced edge-on orientation compared to spin-casting and forms electrically and morphologically consistent films regardless of the pattern width. As a result, the practical large-area integrated OFET arrays on 4 in. wafer substrate exhibited highly uniform electrical characteristics (average field-effect mobility of 0.095 cm2/(V s)) with a deviation value of 0.0109.

No abstract