A new type of low dielectric polyimide/poly(silsesquioxane)-like (PI/PSSQ-like) hybrid nanocomposite material is successfully prepared from the polyimide (ODA±ODPA) precursor containing phenyltrialkoxysilane (PTS) at two chain ends and monoaryltrialkoxysilane with a self-catalyzed sol±gel process. We employ p-aminophenyltrimethoxysilane (APTS) to provide bonding between the PTS and ODPA±ODA phase. It is shown by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) that the PSSQ-like domain sizes with uniform size are fairly well separated in the hybrid ®lms. The silica domain sizes of 5000-PIS and 5000-PIS±50-PTS ®lms are in the range of 30±100 nm, of 5000-PIS±100-PTS and 10000-PIS±100-PTS in the range of 80±200 and 300±600 nm, respectively. The dielectric constant can be 2.79 for 5000-PIS±140-PTS with fairly good mechanical properties. The PI/PSSQ-like hybrid ®lms have higher onset decomposition temperature and char yield in thermogravimetric analysis (TGA) and higher T g in differential scanning calorimetry (DSC) than the pure PI. Moreover, the PI/PSSQ-like hybrid ®lms have excellent transparency even under high PTS content. In the series of X-PIS hybrid ®lms, the coef®cient of thermal expansion (CTE) below T g increases with the PI block chain length, but in the series of X-PIS±y-PTS ®lms, it slightly increases with the PTS content. However, above T g the CTE of X-PIS and X-PIS±24-PTS is much lower than that of the pure PI. The dielectric constant and water absorption of X-PIS±y-PTS ®lms decrease with the PTS content because of the higher free volume and hydrophobicity. q

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In this study, we devised a simple method to enhance the conductivity of poly(3,4ethylenedioxythiophene)-poly(styrene-sulfonate) (PEDOT:PSS) films through spin-coating with various surface-modified compounds, and then applied this technique to the preparation of ITO-free polymer solar cells (PSCs). The electrical conductivity of PEDOT:PSS films can be increased by more than two order of magnitudes merely by spin-coating a compound containing one or more polar groups-such as ethanol, methoxyethanol, 1,2-dimethoxyethane, and ethylene glycol-onto the films. In this paper, we discuss the phenomena occurring through conductivities, morphologies, and chemical properties of the modified PEDOT-PSS films as determined using Raman spectroscopy, a four-point probe, scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The schematic 3D morphological model of directly solvent-modified PEDOT:PSS films is presumed for ITO-free devices. The desirable conductivity enhancements of these materials make them attractive candidates for use as anode materials in ITO-free PSCs.

Highly transparent and stable luminescent ZnO/poly(hydroxyethyl methacrylate) nanocomposites have been synthesized via a nanoparticle surface modified method. 3-(Trimethoxysilyl)propyl methacrylate (TPM) was used as the stabilizing agent in a simple, mild sol-gel route to prepare TPM-modified ZnO nanoparticles. The existence of TPM on the nanoparticle surface effectively promotes the stability of colloidal ZnO nanoparticles and the compatibility between the inorganic nanoparticles and the organic matrix in the solid nanohybrid. The resulting ZnO/PHEMA nanocomposites with TPM-modified nanoparticles have better dispersibility and controllable luminescent properties. The characteristics of TPM-modified and unmodified ZnO nanoparticles have been studied by ultraviolet-visible (UV-vis) absorption spectroscopy, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and 1 H NMR spectroscopy.

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