Fluorescence from fluorescent dye based polyurethane ionomer(III)

A series of reactive fluorescent dyes were successfully synthesized and their structure was proven by IR spectra, NMR spectra, elemental analysis, and mass spectra. The fluorescence performance 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione and 2‐benzyl‐6‐hydroxy‐benzo[de]isoquinoline‐1,3‐dione appears at around 276 and 437.4 nm, respectively, and their quantum yields are 0.662 and 0.562, respectively. It is important to indicate that the fluorescence performance is better for 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione than for as a result of more electron donating groups linked to the 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione molecule. These fluorescent dyes further react with toluene diisocyanate and other additives to form fluorescent dye based polyurethane (PU) ionomer molecules, and their structures are demonstracted by IR spectra. In aqueous solution, the fluorescence performance appears to be better for 6‐amino‐2(‐3‐phenyl‐propyl)‐benzo[de]isoquinoline‐1,3‐dione based PU ionomer than for 6‐amino‐2‐phenyl‐ethyl‐benzo[de]isoquinoline‐1,3‐dione based PU ionomer. For the fluorescent dye based PU ionomer molecule system, the number‐average particle sizes of the fluorescent dye based PU ionomer molecules in water increase with increasing concentration of the fluorescent dye, as a result of the increased free volume of the ionomer molecule. This may be the result of increased intermolecular interactions between ionomer– molecules themselves. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 455–465, 2005     

3D printing robot: model optimization and image compensation

A novel 7-axis robot for industrial large 3D printing applications is presented in this paper,which is developed by Institute of Robotics and Automatic Information System,Nankai University.Base on the prototype,the mechanism on three-dimensional printing is deeply dissected.By investigating the reason of color distortions in 3D printing, a novel multistep compensation algorithm based on model optimization and image compensation is developed.Finally,the experimental results show the performance of the 3D printing robot platform and the proposed algorithms.     

抗氧剂二硬脂基季戊四醇二亚磷酸酯的合成新工艺

本文以季戊四醇、亚磷酸三乙酯和十八醇为原料，在实验室合成了二硬脂基季戊四醇二亚磷酸酯。考查了反应温度、反应时间、催化剂及物料配比对产品收率的影响．实验结果表明，整个工艺过程可分为两步：合成季戊四醇二亚磷酸酯中间体时，最佳的工艺条件为：亚磷酸三乙酯、季戊四醇的摩尔比为2．05：1，催化剂的用量为季戊四醇量的3％，反应温度为13℃，时间为2．5h；在二硬脂基季戊四醇二亚磷酸酯的合成时，十八醇与中间体季戊四醇二亚磷酸酯的摩尔比为2．05：1，反应温度为16℃，时间3h。合成的产品中无酚无三废产生，产品元素分析及红外光谱与目的产物相一致。     

Tacticity effects on the miscibility behavior of poly(methyl methacrylate)/poly(ethylene oxide-b-dimethylsiloxane-b-ethylene oxide) blends

The miscibility of a triblock copolymer poly(ethylene oxide)-poly(dimethylsiloxane)-poly(ethylene oxide) with syndiotactic and isotactic poly(methylmethacrylate) wasstudied. Although isotactic poly(methyl methacrylate) (PMMA) was miscible with poly(ethylene oxide) (PEO) in the pure state, it was immiscible with the PEO end blocks in the copolymer. In comparison, the syndiotactic poly(methyl methacrylate) (sPMMA) was miscible with the PEO blocks as indicated by melting point depression, decrease in crystallinity, and slower rate of spherulite growth of PEO. When blends of the triblock copolymer were cooled to low temperatures, the poly(dimethylsiloxane) (PDMS) middle block which resided in the interlamellar region of PEO spherulites also crystallized; the development of PDMS crystals was clearly suppressed at high sPMMA contents.On leave from Union Chemical Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan     

Aluminum Silicate Films Obtained by Low-Pressure Metal-Organic Chemical Vapor Deposition

Amorphous alumina-silica films with film thickness of 0.41–2.69 μm were prepared on glass and silicon substrates by metal-organic chemical vapor deposition using a mixture of aluminum tri-sec-butoxide (ATSB), hexamethyldisilazane (HMDSN), and argon. By controlling the inputs of ATSB and HMDSN, alumina-silica thin films could contain varied compositions and adjustable properties. Basically, the codeposition of alumina and silica to form alumina-silica using ATSB and HMDSN had a faster growth rate than their individual components. The internal stress could be adjusted by deposition temperature and reactant inputs. Adhesion could be improved by having a silicon-rich thin film, whereas an aluminum-rich film could have slightly higher hardness. Optical properties, e.g., refractive index and optical transmittance, were also measured.     

A highly active bi-crystalline photocatalyst consisting of TiO2 (B) nanotube and anatase particle for producing H2 gas from neat ethanol

Sodium titanate nanotubes (NaTNTs) are converted into monoclinic TiO₂ (B) nanotubes by rinsing with 0.10 M HCl followed by drying at 573 K. As calcination temperature is increased to 673 K, these TiO₂ (B) nanotubes start to transform into anatase nanoparticles producing a bi-crystalline mixture consisting of TiO₂ (B) nanotubes and anatase nanoparticles. The primary particle size of the anatase particles was estimated to be around 10 nm using Scherrer equation. After being promoted with 1% Pt, this bi-crystalline material becomes a very active photocatalyst producing 20% more H₂ gas than 1% Pt/Degussa P-25 TiO₂ in the photocatalytic dehydrogenation of neat ethanol after 2 h of UV light irradiation.     

Effect of surfactants on the particle sizes of red#170 polyurea microcapsules

Red#170 (pigment) polyurea microcapsules have been successfully prepared at our laboratory. Both core and shell of these microcapsules are demonstrated to be red#170 pigment and polyurea, respectively, by infrared (IR) spectra. The number-average particle sizes of these microcapsules are seen to decrease with increasing concentration and the ethylene oxide chain length of nonylphenylpolyoxyethylene ether (NP_n; n = 6, 8, 10, 12, 16) as an emulsifier in the water phase used for making microcapsules. Experimental results indicate that the average particle sizes of red#170 polyurea microcapsules are smaller for the system with NP₁₆ than for the system with NP₄ (in the oil phase) and/or NP₁₆ (in the water phase) and that, in the presence of NP_n, these particle sizes are seen to be slightly smaller for use of methylcellulose than for use of sodium carboxymethylcellulose as a protective colloid. It is also interesting to note that the released amounts of red#170 pigment from polyurea microcapsules in di-n-butylphthalate solvent is lower for a system with NP ₁₆ than for a system with methylcellulose, as a result of good emulsification leading to decrease the interaction between toluene diisocyanate and water molecules. This may further cause more crosslinkage to take place at the urea groups, resulting in a decrease in the porosity of the capsules. © 1994 John Wiley & Sons, Inc.     

Tracking local optimality for cost parameterized optimization problems

In this paper, a procedure for computing local optimal solution curves of the cost parameterized optimization problem is presented. We recast the problem to a parameterized nonlinear equation derived from its Lagrange function and show that the point where the positive definiteness of the projected Hessian matrix vanishes must be a bifurcation point on the solution curve of the equation. Based on this formulation, the local optimal curves can be traced by the continuation method, coupled with the testing of singularity of the Jacobian matrix. Using the proposed procedure, we successfully compute the energy diagram of rotating Bose–Einstein condensates.     

Production of 14-Oxo-<Emphasis Type="Italic">cis</Emphasis>-11-eicosenoic Acid from Lesquerolic Acid by <Emphasis Type="Italic">Sphingobacterium multivorum</Emphasis> NRRL B-23212

The objective of this study was to explore the extent of microbial conversion of lesquerolic acid (14-hydroxy-cis-11-eicosenoic acid; LQA) by whole cell catalysis and to identify the newly converted products. Among compost isolates including NRRL strains B-23212 (Sphingobacterium multivorum), B-23213 (Acinetobacter sp.), B-23257 (Enterobacter cloacae B), B-23259 (Escherichia sp.) and B-23260 (Pseudomonas aeruginosa) the S. multivorum strain was the only microorganism that converted LQA to produce a new product identified as 14-oxo-cis-11-eicosenoic acid by GC-MS and NMR analyses. The conversion yield was 47.4% in 48 h at 200 rpm and 28°C in small shake flask experiments. In comparison, both Acinetobacter and Pseudomonas strains failed to convert LQA to major new products but used LQA apparently as an energy source during fermentation. For structural analysis, 6.88 g of 14-oxo-cis-11-eicosenoic acid was produced from converting 11 g LQA (a 62% yield) in 72 h at 200 rpm and 28 °C in Fernbach flasks using 18-h-old NRRL B-23212 cultures and an improved medium that also contained EDTA and glycerol in lieu of glucose as carbon source. NRRL B-23212 was further identified by 16S rRNA gene sequence analysis as a unique strain of S. multivorum. Therefore, S. multivorum NRRL B-23212 possesses an enzymatic activity presumably a secondary alcohol dehydrogenase for converting LQA to produce 14-oxo-cis-11-eicosenoic acid, a first report that demonstrates the functional modification of LQA by whole cell catalysis.     

Synthesis and Characterization of Polystyrene-b-Poly(4-vinyl pyridine) Block Copolymers by Atom Transfer Radical Polymerization

We aimed at the synthesis of well-define PS-b-P4VP by using atom transfer radical polymerization in two-step process. First, polystyrenes with benzyl bromide end group (PS-Br; by ATRP) were prepared as macroinitiator for the next ATRP of 4-vinyl pyridine and characterized these polymers from ¹H-NMR and MALDI-TOF. Comparing with MALDI-TOF-MS, ¹H-NMR and GPC analyses, this indicates that the formation of the block copolymer can be observed. During the polymerizations, molecular weight distribution and kinetics have been evaluated from GPC traces and ¹H-NMR analyses. We further characterized the thermal properties of these block polymers by DSC and TGA. DSC measurement on the PS-b-P4VP block copolymers exhibited two glass transitions, indicating that the resulting block copolymers are phase separated. Two maxima differential peaks were observed on the TGA trace for the PS-b-P4VP block copolymers might be assigned to the decomposition of the P4VP blocks at 380 ^○C and the PS blocks at higher temperature.