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The combined effect of oxygen and nitrogen functional groups on highly crystalline carbon supports like multiwalled carbon nanotubes (MWCNT) and MWCNT‐few layer graphene hybrid structures (MWCNT+FLG) have been investigated towards oxygen reduction reaction (ORR) performance and carbon corrosion durability in polymer electrolyte membrane fuel cell (PEMFC) applications. The pristine carbon supports were modified with oxygen and nitrogen functionalities by treating with concentrated mineral acids and subsequent nitrogen plasma treatment assisted with R.F. magnetron sputtering. Pt nanoparticles were dispersed over these chemically modified carbon supports by polyol reduction method. The physicochemical properties of as synthesized electrocatalysts were studied by different techniques such as XRD, TEM, FTIR, Raman and XPS. Electrochemical properties were investigated by cyclic voltammetry and linear sweep voltammetry in 0.1M HClO4 medium. Compared to commercial Pt/C catalysts, durability show ∼30 % enhancement for the as prepared electrocatalysts due to the presence of large amount of pyrrolic nitrogen and highly oriented graphitic nature of the catalyst supports. The ORR performance were comparable with Pt/C (TEC10E30E) in terms of MSA, 259, 270, 252 A g−1 for Pt/C, Pt/N‐f‐MWCNT, Pt/N‐f‐(MWCNT+FLG) respectively.

Self-assembly of pristine multi-walled carbon nanotubes (CNTs) in aqueous dispersion using a protein, bovine serum albumin (BSA), has been demonstrated. Step-wise conformational changes in BSA as a function of temperature have been deployed to direct the assembly of nanotubes. More specifically, CNTs distributed randomly in native BSA at 35 °C as well as completely denatured BSA solution at 80 °C self-assemble in the intermediate temperature range of 45-65 °C, as evident from scanning and transmission electron microscopy. Fourier transform infrared (FTIR) and fluorescence studies indicate significant changes in the α-helical content of the protein with respect to the amide I and II bands and tryptophan emission intensity, respectively. The stability of CNT dispersion in BSA solution has been attributed to the hydrophobic interaction between nanotubes and the protein molecule by adding sodium cholate to the dispersion. Moreover, a mechanism based on electrostatic repulsion between BSA-bound CNTs has been proposed for the thermally reversible assembly of CNTs in BSA solution based on evidence from zeta potential measurements and FTIR spectroscopy. Thus the present report demonstrates bio-mimetic self-assembly of as-synthesized CNTs using changes in surface charge and conformation of an unfolding protein for biomedical applications and nanobiotechnology.

N-doped reduced graphene oxide stabilized copper nanoparticles are designed as a heterogeneous catalyst for achieving Cu(i)-catalyzed [3+2] cycloaddition “click” chemistry.

Aim The aim of this study was to evaluate and compare the shear bond strength of hydrophilic materials like Transbond MIP with Assure-fluoride releasing light cure sealant paste system (Reliance orthodontic product), Enhance Lc-adhesion booster (Reliance Orthodontics) Prime and Bond NT–one step adhesive with nanotechnology (Dentsply Product India) with Transbond XT as the control group. Materials and methods The study was conducted on 180 extracted human premolar teeth which were divided into five main groups. Each group contained 36 teeth, which were further subdivided into three subgroups containing 12 teeth. The teeth were bonded in three different surface environments namely dry, contaminated with artificial saliva and reprimed after contamination with artificial salvia. The brackets were bonded and cured. The shear bond strength was tested using Instron universal testing machine (4501). Results The results were subjected to statistical analysis like 3 factorial ANOVA and compared to post-hoc using the Student Newman levels test. The residual resin on the tooth surface after debonding was evaluated with adhesive remnant index. Clinical significance The results revealed that in situations in which moisture contamination is critical there is distinct advantage in using hydrophilic primers. How to cite this article Nirupama C, Kavitha S, Jacob J, Balaji K, Srinivasan B, Murugesan R, Krishnaswamy NR. Comparison of Shear Bond Strength of Hydrophilic Bonding Materials: An in vitro Study. J Contemp Dent Pract 2012;13(5): 637-643.