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An important concern when developing new inks containing novel, bulk, solid-state additives is to ensure consistency during the printing process. In particular, the additives should not build up on the rollers, blankets or plates during printing. In this

This paper describes a newly developed forensic marker technology, known as Datatrace DNA (Digital Nanoparticle Authentication), which offers a groundbreaking approach to counterfeit security protection through nanotechnology that is invisibly embedded within the molecular structure of a manufactured product. Extremely tiny quantities of some security compounds (called security markers) can be incorporated into various sensitive materials, such as explosives, identification documents, printing inks and weapons. Each marker possesses unique or unusual properties that are detected by the Datatrace hand-held electronic reader, known as "The Authenticator". As such, the Datatrace system provides a secure and invisible barcode for authentication. The DatatraceDNA® markers are very stable and cannot be destroyed even at 1000 °C, which provides a life-time protection for the labelled products. Therefore, this novel technology offers the potential to reduce criminal activities by deterring counterfeiting and theft, and assisting in the recovery and return of assets that have been stolen.

In this paper, the polymerization kinetics of unsaturated double bonds (C=C) in TiO2- and ZrO2-doped hybrid polymeric thin films during UV irradiation and thermal curing is studied by monitoring the variation of C=C absorption band at 1630 cm-1 using FT-IR spectroscopic technique. Experimental results showed that polymerization of the unsaturated C=C groups in the TiO2- and ZrO2-doped hybrid polymers can be realized by either photo-irradiation or thermal treatment. The UV-induced polymerization process is much faster than thermal curing, but a full conversion of C=C groups into polyacrylate chains cannot be achieved without thermal treatment. The catalytic effect of TiO2 and ZrO2 on promoting the polymerization of C=C groups was observed, and the time of UV exposure and thermal curing for cross-linking C=C bonds was found to decrease with the increase of the concentration of TiO2 and ZrO2. The activation energy of the hybrid material containing varied concentration of TiO2 and ZrO2 was calculated, and the results indicated that TiO2 is more active than ZrO2 in promoting the polymerization of the unsaturated C=C bonds. Finally, the mechanisms for TiO2 and ZrO2 enhancing the material's photosensitivity (i.e. promoting polymerization of C=C bonds) have been proposed and discussed.

We investigated linear optical and second-order nonlinear optical (NLO) properties of films of poly(bisphenol A carbonate) resin, and a newly synthesised titania/silica/hybrid sol-gel polymer resin doped with Disperse Red 1 (DR1) molecular chromophore. DC electric field induced second harmonic generation (SHG) technique has been used to monitor in situ the polar alignment and relaxation of orientation of the guest molecules in the corona-poled films. The temporal behaviour of the second harmonic signal was remarkably different in these two polymers both during poling and when the poling field was turned off. A fast decay of the second harmonic intensity was observed at room temperature in 3 wt% DR1-doped sol-gel film, and a long relaxation time constant was found in 13 wt% DR1-doped polycarbonate film. Resonantly enhanced d eff coefficient of about 9 pm/V was found in the sol-gel film, and 25 pm/V in the polycarbonate film at the fundamental wavelength 1053 nm. The d 33 values were about 20 pm/V, and 60 pm/V in these films, respectively. The SHG results were used to estimate the average rotation mobility parameter of DR1 molecules in the host polymers.

To achieve a simplified microstructure patterning process, patterning in thin films with a single-step exposure to UV-light or E-beam process for fabrication of integrated optical waveguides and components is of great interest in optics, because the complicated structure developing stage by wet chemical or plasma etching is not required. In this paper, we describe our study on the microstructure patterning in TiO2-doped hybrid glassy polymer thin films by irradiating with focused E-beam. An anhydrous sol-gel process based on hydrolysis and condensation of metal alkoxides with boric acid under non-hydrous conditions was applied to homogeneously incorporating TiO2 into silica network, and transparent glassy TiO2-doped thin films with varied TiO2 concentrations (up to 40 mol%) were prepared by spin coating the hybrid polymer onto fused silica substrates and silicon wafers. The TiO2-doped hybrid material showed a low OH absorption, low optical losses at the telecommunication windows (<0.40 dB/cm at 1550 nm and <0.20 dB/cm at 1310 nm respectively), good thermo-optical linearity and good thermal stability up to 200 °C. Single-step direct surface patterning in the TiO2-doped hybrid glassy films with focused electron beams irradiation showed that tine structure with resolution at submicron level can be fabricated. As the process does not need a developing (etching) process, the profiles of the lines fabricated by the E-beam direct writing showed few distortion. The high precise patterning microstructure with submicron feature sizes in the TiO2-doped hybrid glassy thin films may provide potentials for applications to the fabrication of optical gratings.