Journal Article

Here we report the preparation of mechanically robust silica aerogel polymer nanocomposites using surface-initiated atom transfer radical polymerization. This approach was used to grow poly(methyl methacrylate) (PMMA) with low polydispersities and establish the first structure–property relationship between the grafted PMMA molecular weight and bulk physical properties of the hybrid aerogel.

Strong polymer−silica aerogel composites were prepared by chemical vapor deposition of cyanoacrylate monomers onto amine-modified aerogels. Amine-modified silica aerogels were prepared by copolymerizing small amounts of (aminopropyl)triethoxysilane with tetraethoxysilane. After silation of the aminated gels with hexamethyldisilazane, they were dried as aerogels using supercritical carbon dioxide processing.

A brief review is given about the development of rubber isostatic pressing (RIP) of powders for magnets and other materials that includes: principles of RIP; RIP apparatuses; recent progress; and advantages of RIP. As the recent progress, a new filling technique, ‘air tapping (AT) and grid separation (GS)’, is presented.

Applying RIP (Rubber Isostatic Pressing) to the ferrite sintered magnets, the following have been developed: (1) Ferrite sintered magnets having energy product as high as 5.12 MGOe (2) RIP setup for arc-segment magnets

Abstract BACKGROUND: The powder reaction moulding process uses a reactive monomer as carrier and binder for the moulding of metal or ceramic powders. De-binding is achieved using thermal depolymerisation which is followed by sintering to give the finished component. Binder can be recovered for re-use. RESULTS: Moulding compounds, with various powder volume fractions, have been prepared using stainless steel, silicon nitride and alumina with n-butyl cyanoacrylate as binder, and the stability of the compounds established.

Near-IR reflectance spectroscopy has been used to study the curing of ethyl cyanoacrylate adhesive on polished dental glass and microscope slide substrates. The effects of changing the glue film thickness and the type of substrate on the curing rate have been investigated whilst maintaining a constant humidity. The FTIR spectral data has been used to calculate and plot the extents of cure versus time for various film thicknesses.

Glass ionomer cement (GIC) has been successfully used in dental field for more than 40 years. Despite numerous advantages of GIC, low bond strength and slow setting rate limited conventional GICs for use only at low stress-bearing areas. To improve bond strength to tooth, two kinds of cyanoacrylates such as ethyl 2-cyanoacrylate (EC) and allyl 2-cyanoacrylate (AC) were added in a commercial GIC. Changes in setting time of cyanoacrylate-modified GICs (CMGICs) according to the concentration of cyanoacrylates and/or p-toluene sulfonic acid (TSA) was investigated using a rheometer.

The present work demonstrates feasibility of an inkjettable, isotropically electrically conductive adhesive in the form of a silver loaded resin with a 2-step curing mechanism. In the first step, the adhesive is dispensed (jetted) and precured leaving a “dry” surface. The second step consists of assembly and final curing. The 2-step cure system is based on a Acrylate-Epoxy-Resin matrix with very low viscosity, i.e., 3 mPas of newtonian properties. Spheroidal silver particles of high purity and a compatible organic coating have been loaded at 70% by weight.

Many advanced medical and biological devices require microscale patterning of cells, proteins, and other biological materials. This article describes the use of piezoelectric ink jet processing in the fabrication of biosensors, cell-based assays, and other microscale medical devices. A microelectromechanical system-based piezoelectric transducer was used to develop uniform fluid flow through nozzles and to prepare well-defined microscale patterns of proteins, monofunctional acrylate ester, sinapinic acid, deoxyribonucleic acid (DNA), and DNA scaffolds on relevant substrates.

A photometric assay was developed to study the surface erosion of polymeric nanoparticles. The hydrolytic degradation of polyalkylcyanoacrylate particles was studied in different environments (NaOH, buffer, cell culture medium and serum). The influence of particle modification on the degradation rate was assessed. Particularly, the effect of polymer coating for particle targeting and fluorescence labelling was investigated. From the absorption data, a t 50% and t 100% can be calculated for fast degrading particles and obtained by an extrapolation in case of a slow degradation process.