Investigations of two-photon polymerization of inorganic-organic hybrid materials initiated by femtosecond Ti:sapphire laser pulses are performed. First applications of this technique for the fabrication of three-dimensional microstructures and photonic crystals in inorganic-organic hybrid polymers with a structure size down to 200 nm and a periodicity of 450 nm are discussed.

The development of polymer electrolytes with high ionic conductivity, high lithium transference number, and high electrochemical stability is one of the main aims in the field of lithium battery research. In this work, we describe the synthesis and the characterization of new electrolyte systems, composed of three-dimensional hybrid inorganic−organic networks doped with LiClO 4 . The preparation route comprises only three steps, namely a sol−gel reaction, salt dissolution, and an epoxide polymerization reaction. The lithium concentration, and thus the lithium transference number, was modulated by adding lithium hydroxide in the sol−gel step. In this way, seven electrolytes with varying salt concentrations were prepared. The hybrid electrolytes are characterized by good ionic conductivities (up to 8·10 −5 S/cm at room temperature) and high thermo-mechanical and electrochemical stabilities. Stability tests versus lithium metal via galvanostatic polarization showed that this material is superior with respect to reference poly(ethylene oxide) based electrolytes. W ith the demand for higher energy densities, coupled with the need of increased safety, the electrolyte is considered to be the key component for the development of improved lithium batteries. 1 In particular, much effort is currently spent on the development of solid polymer electrolytes (SPEs) which provide higher thermal stability with respect to standard liquid electrolytes. They also offer better resistance to dendrite formation, thus paving the way for the use of lithium metal anodes and to high energy density batteries such as Li/air and Li/S batteries. 2 The most studied class of polymer electrolytes consists of complexes of poly(ethylene oxide) (PEO) with various lithium salts, as described by Wright and Armand already in the 1970s. 3 These materials are of great interest because of their low cost and toxicity, but the conductivity at room temperature is restricted to ca. 10 −6 S/cm only, which is too low for practical purposes. 4 One of the causes of the low conductivity is the semicrystalline morphology of PEO: ionic conduction occurs predominantly in the amorphous domains, with the crystalline domains playing an impeding role by increasing the tortuosity of the conduction pathways. 5,6 Other drawbacks are the decrease of the mechanical and electrochemical stability at high temperatures 2 and the low Li + transport number. 7 This point is particularly critical for electrolyte application, and it has been variously addressed, either by varying the lithium salt 8 or by developing single-ion conduction electrolytes. 2,9−11 In the field of the binary polyether based electrolytes, one of the easiest and most rewarding research strategies consists of the preparation of composites, in which inorganic particles are dispersed in the PEO matrix. These systems usually benefit from improved mechanical properties and from an increased ionic conductivity. 12,13 The latter effect is attributed to the hindering of the crystallization process or to Lewis acid−ba...

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Sol-gel synthesis allows one to produce inorganic–organic hybrid polymer materials which can be functionalized in order to tailor their physical and chemical properties. Besides, the resulting material properties are significantly influenced by further technological processing of the materials in thin film technology, i.e., the photochemical and thermal curing of the materials. In order to investigate the relationship between technological processing and material properties, a model system containing methacrylic groups as organically polymerizable units is chosen. The degree of conversion of the C=C double bond of the methacrylic group in dependence of the ultraviolet (UV) initiator concentration upon processing is characterized using Fourier-transform infrared spectroscopy. The data are correlated to measurements of the refractive indices at selected wavelengths.

The semiempirical MO method SIN DO^ is extended to second-row atoms from sodium to chlorine. The basis set has a provision to include d orbitals. To retain rotational invariance in a d orbital set, a number of hybrid integrals has to be included that invalidate the zero differential overlap (ZDO) assumption even in a symmetrically orthogonalized basis set. The inclusion of d orbitals rendered the set-up of integral calculation of the original INDO method impractical. Instead of one subroutine for each integral, all explicitly calculated integrals (overlap, core, electronic repulsion) are now contained in a single subroutine under unifying aspects. The parametrization scheme includes pseudopotentials and adjusts the total energy under inclusion of zero point energies to experimental heats of formation of ground states. The vibrational frequencies for the calculation of zero point energies are obtained from calculated force constants and G matrix elements by a scaling procedure. The results for geometries, energies, and dipole moments are compared with MNDO data.