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Abstract Poly(ε-caprolactone) (PCL) is one of the leading biocompatible and biodegradable polymers. However, the mechanical property of PCL is relatively poor as compared with that of polyolefins, which has limited the active applications of PCL as an industrial material. In this study, to enhance the mechanical property of PCL, cellulose nanofibers (C-NF) with high mechanical property, were employed as reinforcement materials for PCL. The C-NF were fabricated via the electrospinning of cellulose acetate (CA) followed by the subsequent saponification of the CA nanofibers. For the enhancement of the mechanical property of the PCL composite, the compatibility of C-NF and PCL was investigated: the surface modification of the C-NF was introduced by the ring-opening polymerization of the ε-caprolactone on the C-NF surface (C-NF-g-PCL). The polymerization was confirmed by the Fourier transform infrared (FTIR) spectroscopy. Tensile testing was performed to examine the mechanical properties of the C-NF/PCL and the C-NF-g-PCL/PCL. At the fiber concentration of 10 wt%, the Young’s modulus of PCL compounded with neat C-NF increased by 85% as compared with that of pure PCL, while, compounded with C-NF-g-PCL, the increase was 114%. The fracture surface of the composites was analyzed by scanning electron microscopy (SEM). From the SEM images, it was confirmed that the interfacial compatibility between PCL and C-NF was improved by the surface modification. The results demonstrated that the effective surface modification of C-NF contributed to the enhancement of the mechanical property of PCL. 

ABSTRACT Polydopamine (PDA) is a biopolymer, which can form uniform thin films on almost all solid substrates as well as at the liquid/air interface. Carbonized polydopamine possesses graphite-like structure and exhibits high electrical conductivity, which makes it a potential carbon-based thin film conductor. However, studies on mechanical behavior of PDA and its derived materials are very limited. In this study, PDA samples were synthesized through self-assembly of dopamine in aqueous solution. Elastic modulus of thin films was measured using the nanoindentation technique. It is shown that the Young’s modulus of PDA thin film increased with increasing heat treatment temperature (up to 600°C). Doping with Cu ions also increased the Young’s modulus of PDA. Furthermore, all PDA thin films, with and without Cu, exhibited creep behavior. 

Abstract In this study, a superhydrophobic and superoleophilic stainless mesh coated with polytetrafluoroethylene/silicon dioxide (PTFE/SiO 2 ) was fabricated through electrostatic self-assembly method followed by sintering treatment. The PTFE was utilized to construct low-surface-energy surface and the SiO 2 nanoparticles were added to enhance its surface roughness. The as-prepared stainless mesh exhibited desirable superhydrophobicity and superoleophilicity with a water contact angle of 152° and oil contact angle of 0°. The coated stainless mesh could separate a variety of oil/water mixtures with high efficiency and it also exhibited good recyclability. Moreover, the corrosion-resistance of stainless mesh was greatly improved by coating it with PTFE. The thermogravimetric analysis (TGA) measurements showed that the coated mesh could withstand high temperature of up to 430°C, indicating excellent thermal-resistance. It is believed that this ultra-robust stainless mesh would have significant potential applications in industry. 

Abstract The actual incorporation of dopant species into the ZnS Quantum Dots (QDs) host lattice will induce structural defects evidenced by a red shift in the corresponding exciton. The doping should create new intermediate energetic levels between the valence and conduction bands of the ZnS and affect the electron-hole recombination. These trap states would favour the energy transfer processes involved with the generation of cytotoxic radicals, so-called Reactive Oxygen Species, opening the possibility to apply these nanomaterials in cancer research. Any synthesis approach should consider the direct formation of the QDs in biocompatible medium. Accordingly, the present work addresses the microwave-assisted aqueous synthesis of pure and doped ZnS QDs. As-synthesized quantum dots were fully characterized on a structural, morphological and optical viewpoint. UV-Vis analyzes evidenced the excitonic peaks at approximately 310 nm, 314 nm and 315 nm for ZnS, Cu-ZnS and Mn-ZnS, respectively, Cu/Zn and Mn/Zn molar ratio was 0.05%. This indicates the actual incorporation of the dopant species into the host lattice. In addition, the Photoluminescence spectrum of non-doped ZnS nanoparticles showed a high emission peak that was red shifted when Mn 2+ or Cu 2+ were added during the synthesis process. The main emission peak of non-doped ZnS, Cu-doped ZnS and Mn-doped ZnS were observed at 438 nm, 487 nm and 521 nm, respectively. Forthcoming work will address the capacity of pure and Cu-, Mn-ZnS quantum dots to generate cytotoxic Reactive Oxygen Species for cancer treatment applications. 

ABSTRACT Climate change and an increase in endangered species, are examples of technological advances negatively impacting the environment. As technology demands increase, an earnest effort to reduce the environmental impact of processing and manufacturing related activities is critical. From a business perspective, minimizing or removing toxic process chemicals is a high impact area that can increase work environment safety and decrease waste management costs. This work presents processing considerations when transitioning to greener alternative polymer resist solvents, for applications in nanomanufacturing with sustainability considerations. Within government contracting, process modifications that change product form, fit, or function require qualification and at minimum justification. This work presents the conversion from a chlorobenzene to anisole based solvent using a 495 kMW polymetheyl methacrylate polymer resin, without impacting form fit or function of the intended device. Resist conversion is of interest as the difference in the substituents of the two solvents, impact the effective toxicity of the polymer resists. Specifically, the oral median lethal dose (LD 50 ) in rats for chlorobenzene is 1110 mg/kg, while anisole is 3700 mg/kg. Therefore, developing a process utilizing anisole and replacing chlorobenzene addresses safety concerns and contributes to green initiatives worldwide. Within this work electron beam lithography fabricated transistor components consisting of a double layered source, and gate were converted from a chlorobenzene to anisole based process; while maintaining process of record specifications. The purpose of this work is to provide a starting platform for individuals seeking to convert from a chlorobenzene solvent to an anisole based resist for sub-micron lithography steps. 

Abstract Ultra deep desulfurization of liquid fuels such as gasoline/diesel has attracted considerable attention of modern clean fuel research due to strict environmental regulations. Apart from that, SO x produced during combustion, poison the catalytic converter and exhaust emission system. Comparing to conventional catalytic and hydrodesulfurization techniques, adsorptive method for removal of sulfur bearing compounds e.g. thiophene derivatives is a promising approach which does not require hydrogen gas and high temperature. In this study, we used nickel sulfide nanoparticles incorporated poly(methyl methacrylate)-zirconia membranes as potential affinity material for adsorptive extraction of dibenzothiophene from n-hexane. The functionality and surface morphology of synthesized material was examined by Fourier transformation infrared (FTIR) spectroscopy and atomic force microscopy (AFM) images, respectively. The quantitative data regarding adsorptive removal of dibenzothiophene was determined by monitoring the shift in absorbance values of standard solutions before and after treating with synthesized material under ambient conditions. Nickel sulphide nanoparticles exhibited suitable rebinding response for removal of dibenzothiophene down to 1 ppm due to affinity interactions which is useful concerning ultra deep desulfurization. Finally, nickel sulphide nanoparticles were incorporated in poly(methyl methacrylate)-zirconia membrane which showed potential application for adsorptive desulfurization of dibenzothiophene at ambient conditions. 

ABSTRACT This work presents the synthesis of selenium-based nanoparticles via microwave-assisted heating and their subsequent characterization using UV-vis Spectroscopy (UV-Vis), high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy (EDX), techniques. Ongoing research includes the study of the nanoparticles capacity to generate reactive oxygen species (ROS). 

ABSTRACT In this study, 3 types of zwitterionic phospholipid biosurfactants LDP(S), CDP(S) and CTDP(S) were prepared from 3 different raw materials such as rapeseed oil, coconut oil and cottonseed oil respectively. The structure of the resulting phospholipid biosurfactants was elucidated by FT-IR, 1 H NMR and 13 C NMR spectroscopies and their interfacial properties have been examined such as CMC, static surface tension, wetting property, solution stability, and foam property. Interfacial property measurement and prescription test in cosmetic formulation prepared with the newly synthesized biosurfactants revealed that CDP(S) biosurfactant possesses excellent mildness and superior interfacial properties, indicating the potential applicability in cosmetic product formulations. 

ABSTRACT Size control of copper fine particles is highly important for their application for conductive materials. In this study, easy size tuning of the copper fine particles coated by n-hexylamine was achieved via controlling the ratio of n-hexylamine and the precursor CuO. The obtained particles were stable and had a hydrophobic surface. TG-DTA measurement revealed the formation of thin layer of n-hexylamine on the particles.