Rapid Prototyping (RP) is a method used everywhere from the entertainment industry to healthcare. Layer orientation is an important aspect of the final product. The objective of this research was to evaluate the effect of layer orientation on the mechanical strength and toughness of a polymer. The polymer used was a combination of two materials, ZP 130 and ZB 58, fused together in the Z Corporation Spectrum Z510 Rapid Prototyping Machine. ZP 130 is a powder composed of vinyl polymer (2-20%), sulfate salt (0-5%), and plaster that contains <1% crystalline silica (50-95%). ZB 58 is a liquid composed of glycerol (1-10%), preservative (sorbic acid salt) (0-2%), surfactant (<1%), pigment (<1%), and water (85-95%). After removal from the machine the samples were sealed with Z bond 101 which is Beta-methoxyethyl cyanoacrylate (60-100%). The layer orientations studied were the crack arrestor, crack divider, and short transverse with various combinations of the three, for a total of seven orientations. The mechanical strength was evaluated using tensile testing and three-point bend testing. The toughness was evaluated by Izod impact testing. Five samples for tensile testing and three-point bend testing as well as 15 samples for the Izod impact test for each of the seven orientations were made. The total number of samples was 175. The crack arrestor orientation was the strongest main orientation for the tensile and three-point bend test. Weibull analysis was done on the Izod impact testing due to high variation in the results for the crack arrestor and short transverse directions. It was found that the layer orientation and surface roughness played a significant role in the penetration of the Z bond 101 coating and in the overall strength of the samples.

To realize the origin of efficient spin injection at organic-ferromagnetic contact in organic spintronics, we have implemented the formation of quasi-molecular magnet via surface restructuring of a strong organic acceptor, tetrafluoro-tetracyano-quinodimethane (F4-TCNQ), in contact with ferromagnetic cobalt. Our results demonstrate a spin-polarized F4-TCNQ layer and a remarkably enhanced magnetic anisotropy of the Co film. The novel magnetic properties are contributed from strong magnetic coupling caused by the molecular restructuring that displays an angular anchoring conformation of CN and upwardly protruding fluorine atoms. We conclude that the π bonds of CN, instead of the lone-pair electrons of N atoms, contribute to the hybridization-induced magnetic coupling between CN and Co and generate a superior magnetic order on the surface.

The spin polarization of organic-ferromagnetic interfaces in an organic spin valve critically affects the efficiency of spin injection or detection. We examined the chemical and electronic properties of ferromagnetic Co deposited on organic Alq3 and the interfacial spin-polarized capability of the electronic states. Our x-ray photoemission spectra and calculations with density-functional theory indicate a sequential and unequal distribution of charge from Co clusters to N and then to O atoms in Alq3. The preferential orbital hybridization at specific functional sites produces efficient spin polarization of organic molecules. Element-specific measurements of x-ray magnetic circular dichroism demonstrate the preferential spin polarization in the lowest unoccupied molecular orbital state of N atoms at the complex interface for Co atop Alq3, which agrees satisfactorily with calculation. Our results indicate that an induced interfacial spin polarization on engineering the dominant reaction of Co with mainly N and O atoms in Alq3 might pave a way for effective spin filtering in organic spintronics.PACS number(s): 79.60. Fr, 75.70.Cn, 68.35.Fx, 75.76.+j Organic spin valves (OSV) in which an organic semicon ductor (OSC) spacer is sandwiched between two ferromagnetic (FM) electrodes have attracted much attention because of an enduring spin coherence of organic materials via weak spin-orbit coupling [1], Dediu et al. pioneered in achiev ing magnetoresistance (MR) up to 30% near 295 K in a LaovSrojMnOsfLSMOj/sexithiophenefTgj/LSMO OSV, ini tiating a great potential of organic-based spintronics [2], Xiong et al. subsequently made a remarkable observation of a giant MR at 40% at 11 K in a LSMO/Alq3/CoOSV [1], Among the most widely used OSC in OSV, tri(8-hydroxyquinoline) aluminum (Alq3) composed of 7r-conjugated molecules is considered to be a promising material for effective spin transport because of its great spin-relaxation time and unique molecular structure [1,3-6], The combination of Alq3 and d -band FM Co has achieved striking MR values [1,7-12], Although an ill-defined layer between Alq3 and top Co was manifested at an Alq3 thickness greater than 100 nm, it is one of few examples in which an OSV displayed a large MR [1], Such an ill-defined layer is ascribed to the diffusion of metal into a soft organic layer, which might be related to the disputed results of the MR sign and mechanism [1,12-15], To prevent the unexpected interdiffusion and chemical interaction at the interfacial region, a buffer layer inserted between the top Co and Alq3 has improved the device performance [9,16-18]. Although metal interdiffusion is preventable with those meth ods, it might not provide a deep understanding of the lacking essential mechanisms [19][20][21]. Moreover, in the case of an OSV with no buffer layer, a large MR was still achieved [1,8]. Various techniques have been used to engineer, to control, or to detect the efficient spin injection and transport [ 1,4,22,23] 'jenghan @ on traditionally applying a specific bias voltage to...

Nitrogen-doped TiO2 nanotube arrays (N-TNAs) were successfully fabricated by a simple thermal annealing process in ambient N2 gas at 450 °C for 3 h. TNAs with modified morphologies were prepared by a two-step anodization using an aqueous NH4F/ethylene glycol solution. The N-doping concentration (0–9.47 at %) can be varied by controlling N2 gas flow rates between 0 and 500 cc/min during the annealing process. Photocatalytic performance of as-prepared TNAs and N-TNAs was studied by monitoring the methylene blue degradation under visible light (λ ≥ 400 nm) illumination at 120 mW·cm−2. N-TNAs exhibited appreciably enhanced photocatalytic activity as compared to TNAs. The reaction rate constant for N-TNAs (9.47 at % N) reached 0.26 h−1, which was a 125% improvement over that of TNAs (0.115 h−1). The significant enhanced photocatalytic activity of N-TNAs over TNAs is attributed to the synergistic effects of (1) a reduced band gap associated with the introduction of N-doping states to serve as carrier reservoir, and (2) a reduced electron‒hole recombination rate.

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