Articles you may be interested inStress-induced transformation behaviors at low temperatures in Ti-51.8Ni (at. %) shape memory alloy Appl. Phys. Lett. 102, 231915 (2013); 10.1063/1.4809935Cu-substitution effect on thermoelectric properties of the TiNi-based shape memory alloys Shape memory effect in nanoindentation of nickel-titanium thin films An incomplete transformation cycle induces a kinetic stop in the following complete transformation cycle in shape memory alloys. Therefore, the kinetic stop can be regarded as a memory of the previous arrest temperature. Herein, we show that the temperature memory effect of a nickeltitanium shape memory alloy can be expanded to be operational in a very wide temperature range by prestraining and constraining, which may be exploited for various practical applications.

A novel hydrophobically modified and cationic flocculant poly(acrylamide-methacryloxyethyltrimethyl ammonium chloride-methacryloxypropyltrimethoxy silane) (P(AM-DMC-MAPMS)) was synthesized by inverse emulsion polymerization. The molecular structure of hydrophobically cationic polyacrylamide (HCPAM) was characterized by FTIR and 1 H-NMR. The effects of DMC and MAPMS feed ratio on intrinsic viscosity and solubility were measured. The effects of hydrophobically cationic flocculants on reactive brilliant red X-3B solution and kaolin suspension were studied. It was found that the introduction of MAPMS could increase the intrinsic viscosities of P(AM-DMC-MAPMS) and enhance the flocculation properties to anionic dye solution and kaolin suspension, but reduced their water-solubility. V

The effect of certain preparative variables, such as the composition of the feeds, the reaction time, catalyst concentration, degrees Centigrade (8C), and the reaction temperature on the properties of prepared polymer poly(lactic acid-glycolic acid-4-hydroxyproline) (PLGAHpr), was investigated via direct melt polymerization with stannous chloride as a catalyst activated by a proton acid. The new polymer had pendant amine functional groups along the polymer backbone chain. The results with regard to the inherent viscosity and yield of PLGA-Hpr are discussed in relation to a recently proposed polymerization mechanism. The content of lactic acid, glycolic acid, and 4-hydroxyproline (Hpr) in the copolymer was found to affect the surface and bulk hydrophilicity of various PLGA-Hpr copolymers. The inherent viscosity of the copolymer and the yield of the reaction depended on the reaction temperature and varied with the reaction time. The higher the 4-hydroxyproline content of the feedzaq, the lower the inherent viscosity of the copolymer and the yield of the reaction. When the glycolic acid content was more than 70% or the content of HPr was more than 10%, the polymer changed from hemicrystalline to amorphous. The in vitro degradation rate of the PLGA-HPr copolymers is dependent on the feed ratios of lactic acid and glycolic acid in the polymer chain. Lactic acid-rich polymers are more hydrophobic; subsequently they degrade more slowly. The structure of this polymer was verified by infrared (IR) spectroscopy, proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy, X-ray diffractometry (XRD), and differential scanning calorimetry (DSC).

In-chain functionalized polystyrenes with different sequential arrangements of functional groups are preparedvialiving anionic copolymerization. The sequence structures are determined by time sampling to establish the sequence-determination method.

The natural planar and rigid structures of most of the hydrophobic photosensitizers (PSs) [such as tetraphenyl porphyrin (TPP)] significantly reduce their loading efficiencies in polymeric nanoparticles (NPs) because of the strong π−π interaction-induced aggregation. This aggregation-caused quenching will further reduce the quantum yield of singlet oxygen ( 1 O 2 ) generation and weaken the efficiency of photodynamic therapy (PDT). In addition, the small molecular PSs exhibit short tumor retention time and tend to be easily cleared once released. Herein, poly(TPP) NPs, prepared by cross-linking of reactive oxygen species degradable, thioketal linkers and TPP derivatives, followed by coprecipitation, were first developed with quantitative loading efficiency (>99%), uniform NP sizes (without aggregation), increased singlet oxygen quantum yield (Φ Δ = 0.79 in dimethyl sulfoxide compared with 0.52 for original TPP), increased in vitro phototoxicity, extended tumor retention time, light-triggered on-demand release, and enhanced in vivo antitumor efficacy, which comprehensively address the multiple issues for most of the PSs in the PDT area.

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This study investigated the effect of internal stress coupling on the deformation behavior of a NiTi matrix-Nb nanowire composite. It is found that residual internal stresses between the nanowires and matrix was created due to the mismatch between the elastic recovery strain of the Nb nanowires and the phase transformation strain of the NiTi matrix. These internal stresses affect the deformation behavior in subsequent deformation cycles, and the effect is dependent on the volume fraction of the nanowires.

SynopsisPoly(ary1 ether ether ketone) is found to he compatible with poly(ary1 ether sulfone) a t a blending temperature 310°C. There is a single glass transition temperature (T,) for various compositions of the blend. The relationship of T, with composition obeys Gordon-Taylor's equation, where the adjustable parameter k is 0.43. Thermodynamic interaction parameter xl2 is estimated to he -0.001 according to Nishi and Wang's melting point depression equation. When the processing temperature is above 350"C, phase separation takes place as shown by a double mechanical loss tangent relaxations in the range of 100-280°C.