In this study Klason lignins from Eucalyptus grandis (LEUG) and Pinus taeda (LPIT) were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TGA). The degradation kinetic parameters were determined by TGA using the Kissinger method. Thermogravimetric results showed that LPIT had higher thermal stability and also higher activation energy than LEUG. FTIR result...

We report a strain sensing approach that utilizes wrinkled patterns on poly (dimethylsiloxane) (PDMS) as an optical grating to measure thermally-induced strain of different materials. The mechanism for the strain sensing and the effect of PDMS grating on strain sensing are discussed. By bonding the PDMS grating onto a copper or silicon substrate, the coefficient of thermal expansion (CTE) of th...

The toughness and coefficient of thermal expansion of a series of functionalized graphene sheet epoxy nanocomposites are investigated. Functionalized graphene sheets are produced by splitting graphite oxide into single graphene sheets through a rapid thermal expansion process. These graphene sheets contain ~ 10% oxygen due to the presence of hydroxide, epoxide, and carboxyl functional groups wh...

IR, X-ray diffraction and thermal analysis were used to illustrate the structure of cerium and thorium laurate in solid state. IR results reveal that the fatty acid exists with dimeric structure through intermolecular hydrogen bonding and cerium and thorium laurate were ionic in nature. The X-Ray diffraction measurements confirm that these soaps posses double layer structure with long spacing. ...

The continuation of Moore’s law by conventional complementary metal oxide semiconductor (CMOS) scaling is becoming more and more challenging, requiring huge capital investments. On proposed scenario is the implementation of compound semiconductors as parts of advanced CMOS devices for More-than-Moore integration. The continuation of improved performance characteristics in CMOS manufacturing is ...

Sintering of nanosilver paste has been extensively studied as a lead-free die-attach solution for bonding semiconductor power chips, such as the power insulated gated bipolar transistor (IGBT). However, for the traditional method of bonding IGBT chips, an external pressure of a few MPa is reported necessary for the sintering time of ~1 h. In order to shorten the processing duration time, we dev...

We report a novel microsensor-based in-situ temperature monitoring method for industrial soft solder die attach processes. The method is demonstrated on an automatic die bonder. Nine aluminum-based thermistors were integrated at several locations on a test chip and read out during the attach process. The aluminum metallization of a commercial CMOS process was used as sensing material. A custom-...

The dissociations of R-hydroxy-N-nitrosopyrrolidine, 1, and R-hydroxy-N-nitrosopiperidine, 2, to form the nitrosiminium ions, 3 and 4, respectively, have been studied as models for the SN1 process of the corresponding R-acetoxy-N-nitrosamines. In excellent agreement with experiments, the ionization of the pyrrolidine derivative is found to be more endothermic at ab initio levels up to MP4(SDTQ)...

Here, we introduce a simple and fast method for bonding a poly(dimethylsiloxane) (PDMS) silicone elastomer to different plastics. In this technique, surface modification and subsequent bonding processes are performed at room temperature. Furthermore, only one chemical is needed, and no surface oxidation step is necessary prior to bonding. This bonding method is particularly suitable for encapsu...

We produced experimentally a new bonding material that consisted of a mixture of a base resin (4-META/MMA-TBB resin adhesive) and thermoexpandable microcapsules for safe, easy debonding. Microcapsules in the base resin would start expansion at 80 degrees C, leading to a remarkable decrease in bond strength. Stainless steel brackets were bonded to bovine permanent mandibular incisors using bondi...