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Inkjet Printed Fractal-Connected Electrodes with Silver Nanoparticle Ink
Vaseem, Mohammad,Lee, Kil Mok,Hong, A-Ra,Hahn, Yoon-Bong American Chemical Society 2012 ACS APPLIED MATERIALS & INTERFACES Vol.4 No.6
<P>The development of a simple and reliable method for nanoparticles-based ink in an aqueous solution is still a challenge for its inkjet printing application. Herein, we demonstrate the inkjet printing of fractal-aggregated silver (Ag) electrode lines on substrates. Spherical, monodisperse Ag nanoparticles have been synthesized using silver nitrate as a precursor, ethylene glycol as a reducing agent, and polyvinyl pyrrollidone as a capping agent. As-synthesized pure Ag nanoparticles were well dispersed in water-ethylene glycol mixture, which was directly used as an ink for inkjet printing. Using this ink, the Ag electrodes of fractal-connected lines were printed on Si/SiO<SUB>2</SUB>, glass, and polymer substrates. The fractal-connected Ag lines were attributed to the diffusion-limited aggregation of Ag nanoparticles and the effect of annealing on conductivity was also examined.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2012/aamick.2012.4.issue-6/am300689d/production/images/medium/am-2012-00689d_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am300689d'>ACS Electronic Supporting Info</A></P>
Vaseem A. Ansari,Muhammad Arif,H. H. Siddiqui,R. K. Dixit 경희대학교 융합한의과학연구소 2016 Oriental Pharmacy and Experimental Medicine Vol.31 No.4
In the present study, triterpenoidal glycoside was isolated from ethanolic extract of aerial part of the plant Nepeta hindostana. The ethanolic extract was subjected to Si-gel CC and compound was isolated. The isolated compound Napedinolside has been characterized as 1β,11α,30-trihydroxy-lup-20(29)ene-(3 → 1′)-β-D-pyranoside on the basis of spectroscopic (UV, IR, 1H, 13C NMR and MS) methods. The ethanolic and aqueous extract at different concentrations were screened for antiplatelet activity using platelet rich plasma (PRP) prepared by centrifugation of rabbit whole blood (containing 0.9 % sodium citrate as anticoagulant) at 1500 rpm for 15 mins. The Np-01 was identified as triterpenoidal glycoside which was amorphous brownish white powder; yield 0.64 % (w/w); mp 125–127. N. hindostana showed very excellent antiplatelet activity in both aqueous and alcoholic extracts. The minimum concentration showed antiplatelet activity was 0.5 μg/ml. These findings demonstrate that ethanolic and aqueous extract of the selected plant material at different concentrations showed significant antiplatelet activity. The triterpenoidal glycoside from aerial parts of N. hindostana could hold promise for future application in the treatment of blood clot and pulmonary embolism related diseases.
Vaseem Ahmad Ansari,Muhammad Arif,Md. Sarfaraj Hussain,Hefazat Hussain Siddiqui,Rakesh Kumar Dixit 한국한의학연구원 2016 Integrative Medicine Research Vol.5 No.4
Background The fruit Terminalia belerica is a rich source of vitamins, acids, and nutraceuticals which have free radical scavenging activity. Thus, the ethanolic extract of fruit and its isolated compound (Tb-01) were intended to estimate antiplatelet and antioxidant activities. Methods The ethanolic extract was submitted to Si-gel CC and the compound was isolated. The compound Tb-01 was characterized as benzoyl-β-D-(4′→10″ geranilanoxy)-pyranosides on the basis of spectral data [ultra violet (UV), infrared (IR), 1H nuclear magnetic resonance (NMR), 13C NMR, and Mass Spectroscopy] and chemical analyses. The ethanolic extract and Tb-01 at different concentrations were in vitro screened for antiplatelet and antioxidant activity. The antiplatelet activity was carried out by using platelet rich plasma prepared by centrifugation of rabbit whole blood (containing 0.9% sodium citrate as anticoagulant) and antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl, reducing power, and nitric oxide anion scavenging activity models. Results The compound Tb-01 was an amorphous brownish powder, yield 0.64% (w/w), melting point 105–110 °C, Retardation factor/Retention Value (Rf value) at 0.42 in methanol:chloroform (20:80) solvent system, UV absorption maxima at 243 nm, and molecular peak [M + H]+ at 394.15 m/z. It was observed that the ethanolic extract and Tb-01 at different concentrations showed significant antiplatelet and antioxidant activity. The antioxidant activity, like scavenging of 1,1-diphenyl-2-picrylhydrazyl radicals, nitric oxide radical, and reductive power were found to be concentration-dependent and increased when increasing amounts of sample were used. Conclusion Mass spectra and 1H NMR confirmed the isolated compound structure which was supported by 13C NMR and IR spectra. Tb-01could be promising for future applications in the treatment of blood clots, pulmonary embolism, and other related diseases.
Synthesis of ZnO nanoparticles and their ink-jetting behavior.
Vaseem, Mohammad,Lee, Kil-Mok,Shin, Jin-Koog,Hahn, Yoon-Bong American Scientific Publishers 2012 Journal of Nanoscience and Nanotechnology Vol.12 No.3
<P>Zinc oxide (ZnO) nanoparticles were synthesized by ultrasonically-assisted solution process without using any surfactants. The as-synthesized spherical ZnO nanoparticles with diameter of 20 +/- 5 nm possessed crystalline nature with wurtzite hexagonal phase and showed a blue-shifted near band-edge ultra-violet absorption at -340 nm due to quantum confinement effect of ZnO nanoparticles. The as-synthesized ZnO nanoparticles were further formulated as an ink for ink-jet printing application. Jetting and writing of various line patterns on Si and ITO substrates were demonstrated using the as-formulated ZnO ink. UV-treated substrates showed an improvement in the fixation of ink on substrate due to decreased contact angle with controlled surface wettability.</P>
Low temperature preparation of CuO nanospheres and urchin-shaped structures via hydrothermal route
Khan, R.,Vaseem, M.,Jang, L.W.,Yun, J.H.,Hahn, Y.B.,Lee, I.H. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.609 No.-
We demonstrated a simple one-step hydrothermal route for the preparation of cupric oxide (CuO) nanoparticles in the form of either nanospheres or urchin-shaped structures. The choice between these two types of structures was easily achieved by switching between NaOH or NaBH<SUB>4</SUB> during the nanoparticles synthesis. The first resulted in the production of nanospheres, the second gave rise to the urchin-like structures. Possible growth mechanisms for the formation of CuO nanospheres were discussed. Structural and optical properties of these nanospheres were investigated and their band-gap was found to be 1.54eV. The higher band-gap value compared to the bulk CuO was attributed to the strong quantum confinement of charge carriers in the small nanoparticles comprising the nanospheres.
Improved Optical Transparency of CuO Films Prepared by using Quantum-dot Ink on Glass Substrates
Rizwan Khan,Jin Hyeon Yun,이인환,Mohammad Vaseem,한윤봉 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.1
The present investigation reports a simple solution process for synthesizing CuO quantum dots at low temperature without using surfactants or templates. Detailed structural characterizations revealed that the as-prepared CuO quantum dots were uniform and dense with high crystallinity. As-prepared CuO quantum dots were used as an ink to prepare CuO films on glass substrates via a spin-coating method. The effects of annealing temperature on the optical properties of CuO films were investigated. The optical transparency of the CuO films showed an improved transmittance of > 80% at a wave length of 800 nm after annealing at 300 C. In addition, the band-gap energy was observed to decrease from 1.70 to 1.28 eV with increasing annealing temperature from 300 to 500 C due to the improvement in the crystallinity with grain growth in the films.
Kim, Jin-Hwan,Kim, Haslin,Vaseem, Mohammed,Hahn, Yoon-Bong American Scientific Publishers 2013 Journal of Nanoscience and Nanotechnology Vol.13 No.10
<P>The effects of gas atmosphere and sputter time for depositing silver (Ag) on the structural, optical and electrical properties of ZnO/Ag/ZnO transparent conducting oxide (TCO) films have been investigated with sputtering Ag target in Ar or N2. It was found that the properties of the Ag and ZnO/Ag/ZnO films are quite dependent on the gas environment and the sputter time. The optical transparency of ZnO/Ag/ZnO films was easily controllable when sputtering the Ag target in N2 rather than in Ar. With optimizing the sputter time and atmosphere for Ag adsorption, the ZnO-based TCO films where the Ag layer was embedded in N2 yielded low resistance of 6.1-9.1 omega/sq and high transmittance of 93-96% over the visible range of wavelengths.</P>
Improved optical transparency of cuo films prepared by using quantum-dot ink on glass substrates
Khan, Rizwan,Yun, Jin Hyeon,Lee, In-Hwan,Vaseem, Mohammad,Hahn, Yoon Bong 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol. No.
<P>The present investigation reports a simple solution process for synthesizing CuO quantum dots at low temperature without using surfactants or templates. Detailed structural characterizations revealed that the as-prepared CuO quantum dots were uniform and dense with high crystallinity. As-prepared CuO quantum dots were used as an ink to prepare CuO films on glass substrates via a spin-coating method. The effects of annealing temperature on the optical properties of CuO films were investigated. The optical transparency of the CuO films showed an improved transmittance of > 80% at a wave length of 800 nm after annealing at 300 A degrees C. In addition, the band-gap energy was observed to decrease from 1.70 to 1.28 eV with increasing annealing temperature from 300 to 500 A degrees C due to the improvement in the crystallinity with grain growth in the films.</P>