Papers by Author: Qiu Ling Chen

Abstract: Surface treatment before glass bonding is an important and critical issue for glass-based lab-on-chip fabrication. In the present article we verified five different activation methods for obtaining sound thermal assisted direct bonding (TADB) on glasses. Glass surface has been investigated by means of water contact angle, X-ray photoelectron spectroscopy (XPS). The optimum surface activation method for TADB on glasses was found to be H₂SO₄:H₂O₂ (3:1 by volume) followed by HNO₃. By using the TADB optimized activation method, the glass bonding strength higher than 32MPa was obtained with a glass the roughness of 50 nm.

Abstract: . Fe3O4 nanoparticles were synthesized and doped into two glass systems (Na2O-B2O3 glass and PbO-Bi2O3-B2O3-GeO2 glasses) at low concentrations using traditional glass melting method. The formation of Fe3O4 nanoparticles was obtained through coprecipitation of Fe(II) and Fe(III) in alkaline media.The size of the Fe3O4 nanoparticles was observed to be around 15 nm. The structure and properties of doped glasses were studied by X-ray diffraction (XRD), scanning electric microscope (SEM), UV-VIS spectray, FT-IR spectray analysis and Faraday rotation test. Compared to the host glass, Fe3O4 nanoparticles doped glasses shown enhanced Faraday Effect in term of Verdet constant and will have potential application in magneto-optical devices.

Abstract: Fe3O4 nanoparticles doped magnetic-optical PbO-Bi2O3-B2O3 glasses were prepared and studied and the effects of Fe3O4 nanoparticle on the properties of magnetic-optical glass were analyzed. It is found that the doping of Fe3O4 nanoparticles into glasses increased the Verdet constant of magneto optical glass without evident degradation in glass transmittance. The formation of Fe3O4 nanoparticles was obtained through coprecipitation of Fe(II) and Fe(III) in alkaline media. The structure and properties of doped glasses were studied by X-ray diffraction (XRD), scanning electric microscope (SEM), UV-VIS spectray analysis and Faraday rotation test etc.

Abstract: A modified rod in tube technique for tellurite glass preform fabrication is reported, and the effects of the fabrication process on the preform quality are discussed in terms of different processing factors. The conditions for obtaining good quality of reproducible preforms were experimentally investigated. Preforms with a good interface between core and cladding were obtained by this technique, then drawn to fiber.

Abstract: An overview of the last 16 years of activity on joining of advanced ceramics, glasses and ceramic matrix composites at Politecnico di Torino (Italy) will be presented. Results on thermal assisted direct bonding (TADB) of glasses for lab-on-chip devices, C/C composites to Cu-alloys for nuclear fusion components (ITER), SiC and SiC/SiC joints for nuclear components (fusion and fission), glass joining of foam glass, C/C joints for aerospace applications, ceramics to stainless steels for Solid Oxide Fuel Cells (SOFC), will be shown. Mechanical tests on joined components will be discussed, in particular, the results of an experimental campaign on carbon/carbon and ceramic joints tested in pure and apparent shear by nine different configurations.