Tin dioxide （SnO2） nano-particles were prepared on high silica TON, MFI and FAU type zeolites by impregnation of SnC12 solution and subsequent calcination at 873 K. XRD and SAED were used to characterize the crystal...
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Tin dioxide （SnO2） nano-particles were prepared on high silica TON, MFI and FAU type zeolites by impregnation of SnC12 solution and subsequent calcination at 873 K. XRD and SAED were used to characterize the crystalline phase, and TEM was used to characterize the morphology, the particle size and the agglomerative state of the formed nano-materials. The nano-particles, which possess 8 nm, 10-80 nm and 6 nm in size, were found to form on the outer surface of TON, MFI and FAU zeolites, respectively. SnO2 microcapsules and SnOz netlike nanostructure were obtained by decomposition of SnO2-TON and SnO2-MFI in 40% hydrofluoric acid at room temperature. Compared with the nano-particles formed on NaY zeolite, the special morphology and the agglomerative state of SnO2 nanostructures on TON and MFI type zeolites with one and two dimension channel system indicate that the heterogeneous framework, surface structure and property perform important function for forming and growing SnO2 nanostructure on the outer surface of the zeolites.
Surface‐biofunctionalized synthetic polymer fibers composed of a fiber‐forming host polymer and an oligopeptide conjugate can be prepared from electrospinning, report Spontak and co‐workers on p. 87. The conjugate ...
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Surface‐biofunctionalized synthetic polymer fibers composed of a fiber‐forming host polymer and an oligopeptide conjugate can be prepared from electrospinning, report Spontak and co‐workers on p. 87. The conjugate consists of a polypeptide segment and a polymer block that is compatible with the host polymer. Because the more polarizable peptide segment migrates to the surface during electrospinning, peptide surface‐enrichment is achieved in a single step without further treatment.
The effect of sodium alginate, as binder, and polyethyleneglicol, as plasticizer, on rheological and mechanical properties of suspensions used in water-based tape casting of LZSA glass ceramics was studied. The invest...
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ISBN:
(纸本)0470080507
The effect of sodium alginate, as binder, and polyethyleneglicol, as plasticizer, on rheological and mechanical properties of suspensions used in water-based tape casting of LZSA glass ceramics was studied. The investigation was carried out using a statistical design approach. An aqueous suspension of a parent glass from the LZSA (Li2O-ZrO2SiO 2-Al2O3) system was used. Viscosity, thixotropy and yield stress behavior were measured for the aqueous suspensions as a function of additive composition. Tensile strength of cast tapes was also measured. The experiments were shown to be statistically significant.
Novel carbosilane liquid crystalline dendrimers based on 1,6-hexanediol were prepared. Using the precursors Gn-C1 （n = 1-3） with Si-C1 bonds on the periphery as dendritic scaffolds and 4-[4-（6-hydroxyhexyloxy）phen...
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Novel carbosilane liquid crystalline dendrimers based on 1,6-hexanediol were prepared. Using the precursors Gn-C1 （n = 1-3） with Si-C1 bonds on the periphery as dendritic scaffolds and 4-[4-（6-hydroxyhexyloxy）phenylazo]- nitrobenzene as mesogenic group, a series of carbosilane liquid crystalline dendrimers from the first to the third generation were synthesized. These carbosilane liquid crystalline dendrimers showed smectic phase.
Commercial polyurethane foams with a monomodal pore size distribution were used to produce LZSA glass ceramic foams by the polymeric sponge method. A suspension containing LZSA glass ceramic, bentonite and sodium sili...
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ISBN:
(纸本)0470080507
Commercial polyurethane foams with a monomodal pore size distribution were used to produce LZSA glass ceramic foams by the polymeric sponge method. A suspension containing LZSA glass ceramic, bentonite and sodium silicate, was prepared in water and isopropanol media to impregnate the polymeric foams by dip coating. The suspension was characterized by Theological measurements. The effect of the solvent on the microstructure and physical properties on the LZSA foams was also evaluated. The cellular microstructure of the glass-ceramic foams was characterized by scanning electron microscopy (SEM) and micro-computer X-ray tomography (μ-CT). The LZSA foam prepared with isopropanol suspension exhibited higher mechanical strength under compression than those prepared with water.
Supercritical CO2 (sc-CO2) was first time utilized to make germanium (Ge) nanocrystals by thermolysis of diphenylgermane (DPG) or tetraethylgermane (TEG) with octanol as capping ligand at 500°C and 27.6 MPa. A ne...
Supercritical CO2 (sc-CO2) was first time utilized to make germanium (Ge) nanocrystals by thermolysis of diphenylgermane (DPG) or tetraethylgermane (TEG) with octanol as capping ligand at 500°C and 27.6 MPa. A new approach to prepare Ge nanocrystals of high chemical yield by reduction of GeI2 with LiAlH4 in trioctylphosphine (TOP) at 300°C is also presented. In both cases, Ge nanoparticles with high crystallinity were observed with high resolution transmission electron microscopy (HRTEM), and the presence of Ge was confirmed by X-ray diffraction (XRD) pattern. Compared to the supercritical organic solvents investigated in the previous study to make Ge nanoparticles, the reaction in sc-CO2 produced much less organic contaminants and made the removal of by-products and cleaning of the nanocrystals much easier. While Ge nanoparticles were synthesized in sc-CO2 with DPG and octanol, bulk Ge instead of nanoparticles was obtained without the presence of CO2 at the same concentration of DPG and octanol. High chemical yield of up to 75% was achieved for the Ge nanoparticles made from GeI2 with TOP, and only minimal cleaning is required to obtain Ge nanocrystals with high purity.
A reactive extrusion process was developed improving the rheological properties of PET via the coaddition of a dianhydride and polyol. Specifically, the coaddition of pyromellitic dianhydride (PMDA) with pentaerythrit...
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This paper explores the development of and pilot study done on an online textbook and research tool, based on the book, "how to model it", by Starfield, Smith and Bleloch. In many engineering design texts, t...
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This paper explores the development of and pilot study done on an online textbook and research tool, based on the book, "how to model it", by Starfield, Smith and Bleloch. In many engineering design texts, the solution(s) to design problems are provided in the pages following the proposed problem. With this online system, students are able to read only a portion of the text, and then must complete one or more tasks for which they submit a response to the system. This approach forces the students to begin practicing the engineering design process, rather than simply reading about someone else's design process. As a research tool, the computerized method of data gathering addresses the issue of increasing sampling frequency without much larger investment in research time, as no transcription is required. The small pilot study showed students' responses included data on their design process thinking as well as their proposed solution to the problems
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