Ethylene–propylene copolymer/ordered polysilsesquioxane nanocomposites prepared via organic acid‐ or base‐catalyzed binary silica water‐crosslinking reactions

In situ silica sol–gel‐derived organic–inorganic hybrid materials, which comprise a vinyltrimethoxysilane‐grafted ethylene–propylene copolymer (EPR‐g‐VTMS) and n‐hexyltrimethoxysilane (HTMS), were successfully prepared in the presence of an organic acid and base catalyst. Benzenesulfonic acid and aniline were selected as the organic acid and base catalyst, respectively, to examine the progress and effect of progressive changes in the silane water‐crosslinking reaction of EPR‐g‐VTMS/HTMS composites. The water‐crosslinked EPR‐g‐VTMS/HTMS composites were characterized by means of attenuated total reflectance Fourier transform infrared spectroscopy, gel content, solid‐state ²⁹Si cross‐polarization/magic‐angle spinning NMR, wide‐angle X‐ray scattering, tensile strength and field‐emission scanning electron microscopy measurements. These results revealed that the type of catalyst has a substantial influence on the nature of siloxane bonds and eventually the physical tensile properties of the water‐crosslinked EPR‐g‐VTMS/HTMS composites, which can be explained mainly from knowledge of the traditional acid‐ and base‐catalyzed silica sol–gel reaction. Moreover, an in‐depth analysis of the aniline‐catalyzed composites indicated the formation of ladder‐type poly(n‐hexylsilsesquioxane)s and the presence of a highly ordered structure with a thickness equal to the length of two n‐hexyl groups in all‐trans conformation. We demonstrate potential for the future design of highly ordered silicate‐based organic–inorganic hybrid nanocomposites. Copyright © 2009 Society of Chemical Industry     

Supramolecular Materials from Inorganic Building Blocks

Inorganic materials of nanometric dimensions and controllable morphologies are now widely available permitting their use as building blocks in supramolecular structures. Incorporation of inorganic blocks into hybrid structures can yield unique materials that have no naturally occurring or organic synthetic analogues. In this short review, we describe the construction and functions of supramolecular materials prepared using inorganic building blocks, with emphasis on material-like components. Examples described in this review are categorized as (i) inorganic structures within organic assemblies (silica-supported Langmuir monolayers, organic–inorganic lipid bilayer vesicles etc.), (ii) organic components in inorganic nanospaces (mesoporous materials including biocomponents such as peptides and proteins), (iii) organic/inorganic nanohybrid blends (nanorod-liquid crystal blends and surfactant-guided gold nanostructures), and (iv) hierarchic structures (layer-by-layer assemblies of mesoporlous carbons and capsules).     

No. 5Vol. 42, No. 2, pp. 110–120, 2008Design and development of an innovative hybrid powder based on a computer simulation and its application to base make up products

An innovative hybrid powder prepared through computer simulation allowed a new foundation to be developed having a fine, smooth texture that has never been achieved before. The optical structure/design of the powder was based on the results of measurements and analyses conductedon the optical characteristics of a baby's fine skin that is the envy of many women. In order to achieve the optimal optical characteristics, the Finite Differential Time Domain (FDTD) method to solve Maxwell's differential equation by difference and time domain was applied to the computer simulation method. For the synthesis of the hybrid powder based on the optical model, a proprietary shape regulation coating technology was used, in which flaky substrates were coated with micro-spherical forms of barium sulfate crystals. The developed hybrid powder exhibited optical characteristics that showed a significant diffusion characteristic in the visible light region. The foundation containing this powder could conceal pores, fine wrinkles, freckles, and spots, and provided a fine, smooth texture owing to its microscopic reflection characteristics that has never been available from a conventional foundation.     

Physical and electrochemical characterization of ionic liquids based on quaternary phosphonium cations containing a carbon–carbon double bond

Physical and electrochemical characterizations of novel two ionic liquids based on quaternary phosphonium cations containing an unsaturated carbon–carbon bond (triethyl(4-pentenyl)phosphonium and allyltributylphosphonium cations) are presented in this report. It was found that both unsaturated phosphonium cations gave low-melting salts in combination with a bis(trifluoromethylsulfonyl)amide anion. The thermogravimetric analysis suggested that the unsaturated phosphonium ionic liquids showed higher thermal stability than those of the corresponding saturated phosphonium ILs. The unsaturated phosphonium ionic liquids also exhibited relatively low viscosity and high conductivities when compared to those of the corresponding saturated phosphonium ionic liquids. These results indicate an improving effect of introducing a carbon–carbon double bond into the phosphonium cations on both the thermal stability and the transport property. The voltammetric measurements suggested that the triethyl(4-pentenyl)phosphonium-based ionic liquid showed a high cathodic stability, enabling the deposition and dissolution of metallic lithium in the phosphonium ionic liquid system.     

Measurement of the amount and number of pollen particles of Cryptomeria japonica (taxodiaceae) by imaging with a photoacoustic microscope

A photoacoustic microscope (PAM), which includes a condenser microphone and a pair of linear-motor-driven pulse stages, was specially designed for spectroscopic applications. The PAM was applied to measure the amount and number of pollen particles of Cryptomeria japonica (CJ), which is known for its allergic function against eyes and nose. The advantage of photoacoustic (PA) imaging is both its high sensitivity and its counting ability up to high concentrations of the specimen. The CJ pollen particles were fixed on a piece of adhesive tape or on albumen (egg white) on a glass slide set in a PA cell. The PA image showed the ability of this method to count CJ pollen from the several-hundred-milligram region to even a single particle. The PA signal obtained was integrated over the specimen surface. The dependence of the PA signal on the amount or number of the pollen particles was measured. The resulting coefficients of correlation of the calibration curves for the amount and the number of pollen particles were 0.94 and 0.97, respectively.     

Mechanical control of nanomaterials and nanosystems

In situations of power outage or shortage, such as periods just following a seismic disaster, the only reliable power source available is the most fundamental of forces i.e., manual mechanical stimuli. Although there are many macroscopic mechanical tools, mechanical control of nanomaterials and nanosystems has not been an easy subject to develop even by using advanced nanotechnological concepts. However, this challenge has now become a hot topic and many new ideas and strategies have been proposed recently. This report summarizes recent research examples of mechanical control of nanomaterials and nanosystems. Creation of macroscopic mechanical outputs by efficient accumulation of molecular-level phenomena is first briefly introduced. We will then introduce the main subject: control of molecular systems by macroscopic mechanical stimuli. The research described is categorized according to the respective areas of mechanical control of molecular structure, molecular orientation, molecular interaction including cleavage and healing, and biological and micron-level phenomena. Finally, we will introduce two more advanced approaches, namely, mechanical strategies for microdevice fabrication and mechanical control of molecular machines. As mechanical forces are much more reliable and widely applicable than other stimuli, we believe that development of mechanically responsive nanomaterials and nanosystems will make a significant contribution to fundamental improvements in our lifestyles and help to maintain and stabilize our society.     

Wet releasing and stripping SU-8 structures with a nanoscale sacrificial layer

This paper presents a new method of wet releasing SU-8 structures using very thin Omnicoat^™ as sacrificial layer and NMD-3 developer as releasing solution. Four-inch sized SU-8 structures with different pattern and thickness of 65 μm have been successfully released from silicon substrate by this method. Experiments show that Omnicoat^™ layer is very helpful to strip SU-8 molds in which metal structures are electroplated. SU-8 can be removed directly using remover if there is an Omnicoat^™ layer between the substrate and SU-8 and the electroplated structures is with large dimension. In the case of electroplated structures with small feature size, SU-8 can be removed by combining wet stripping and plasma etching. Nickel micro coils with linewidth of 10 μm and aspect ratio of 4.1 have been fabricated. The analysis about the influence of Omnicoat^™ layer’s thickness on integrity of SU-8 micro coils is also given in our work.     

Novel Highly Acidic Nanoporous Cage Type Materials and Their Catalysis

Acylation of aromatic compounds such as veratrole (1,2-dimethoxybenzene), anisole, isobutyl benzene, and 2-methoxynaphthalene with acetic anhydride (Ac₂O) has been investigated over different solid acid catalysts such as MWW, BEA, FAU, MOR, and MFI. MWW catalysts have been characterized by X-ray diffraction, N₂ adsorption–desorption isotherm, and HR-FESEM characterization techniques. The reaction is studied in the temperature range 313–353 K under N₂ atmosphere. Among the catalysts tested, MWW was found to be more active than other zeolites. This is mainly due to its three dimensional porous structure with excellent textural characteristics. The effect of veratrole/Ac₂O molar ratio, catalyst concentration, and reaction temperature has been optimized to get higher conversion of Ac₂O. Under the optimized reaction conditions, MWW gave the Ac₂O conversion of 64.3% with a selectivity to acetoveratrone (3′,4′-dimethoxyacetophenone) (100%). It was also found that the structural features and acidity play an important role in the conversion and product distribution in the acylation of different aromatic substrates like anisole, isobutyl benzene, and 2-methoxy naphthalene. MWW catalyst has been reused in few cycles after regeneration by washing with ethyl acetate followed by calcination at 500 °C for 4 h without loss in its activity. The reaction kinetics of the catalyst was also studied and the results are discussed in detail.     

Properties of biomedical pressure-sensitive adhesive copolymer films with pendant monosaccharides

Glucosyloxyethyl methacrylate (GEMA) was copolymerized with butyl acrylate (BA) for the preparation of a biomedical pressure-sensitive adhesive with pendant monosaccharides, for possible use in medical applications. The measurements of 180° peel strength, ball tack, and holding power for the GEMA–BA copolymer films revealed that the film at the GEMA content of 5 mol % has excellent pressure-sensitive adhesive properties. Protein adsorption onto the GEMA–BA copolymer film hardly occurred due to very low interfacial free energy between its surface and water. Release profiles of vitamin B₁₂ from the GEMA–BA copolymer film suggests that it is useful as a material for a transdermal therapeutic system. © 1995 John Wiley & Sons, Inc.