eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
3
12
4000
Huge opportunities for industry of nanofibrous concrete technology
Abdullah Keyvani
1
Department of Civil Engineering, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran
In spite of the fact that cementitious and concrete materials are mainly used on a large scale and in huge quantities for roads, dams, bridges and building constructions, the mechanical behavior of these materials depends to a great extend on structural elements and phenomena which are effective on a micro and nanoscale. Although this is well known by researchers, material producers and engineers for many years, the aspect of nanoscience and nanotechnology has hardly found any special attention, so far. New efforts and possibilities of material engineering on nanoscale in other fields may well lead to a new leap forward to improve mechanical and physical properties as well as durability of this important group of composite construction materials. This paper intends to stimulate the application and development of nanoscientific and nanotechnological concepts of nanofiber materials and their applications in concrete. Due to the wide range of possibilities, however, it does not claim to present a complete overview of the whole field. This would clearly go beyond the scope of this paper. It rather gives a short outline on the related cementitious and concrete material problems and research topics where nanoscience and nanotechnology could produce a major contribution to improve the nanofibrous materials where research needs to be done. Capability to accurately predict failure in joints offers significant potential for developing higher performance structural designs that are safer at the same time since these nanotubes can be used to accurately assess the behavior of joints, members and structures. Nanofibrous cement based materials can monitor regions of partial damages, localized changes in strains, stresses and temperatures of any joints and members.
https://www.ijnnonline.net/article_4000_668e5f906baa878917e88ab23cf85666.pdf
Nanotechnology
Cement
Concrete
Nanofibrous
Carbon nanotubes
Multy-wall nanotubes
Single-wall nanotubes
Strength
eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
13
20
4001
Preparation of MCM-41 nanofluid and an investigation of Brownian movement of the nanoparticles on the nanofluid conductivity
A. Amrollahi
1
A. A. Hamidi
2
A. M. Rashidi
3
Faculty of Chemical engineering, University College of Engineering, University of Tehran, I. R. Iran
Faculty of Chemical engineering, University College of Engineering, University of Tehran, I. R. Iran
Gas Division ,Research Institute of Petroleum Industry (RIPI)
In this investigation the silicate nano structure of MCM-41 has been used for the production of nanofluid. The particles have negligible heat conductivity and therefore by their dispersion in a base fluid like water, it is possible to study the increase of heat conductivity due to the Brownian motion effects. In this work a suitable apparatus for the measurement of heat conductivity has been built and calibrated and then using the apparatus and preparing suitable nanofluids, the conductivity and the volumetric heat capacities have been measured. Experimental results show that the preparation time of the nanofluid using the ultrasonic method has pronounced effect on the increase of the conductivity. A twenty four hours preparation time for the nanofluid containing 2.5% (vol) of the particles results in a 7% increase in the conductivity of the base fluid while showing no significant increase in the volumetric heat capacity. Investigating the effect of increasing the temperature and volumetric percentage of the particles it can be deduced that Brownian nano particles movement is one of the main factors in increasing the thermal nanofluids conductivity.
https://www.ijnnonline.net/article_4001_49f3625ea54127f7513205579749c762.pdf
nanofluid
Nano particles
Effective thermal conductivity
specific heat capacity
eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
21
36
4002
Diamondoids and DNA Nanotechnologies
Hamid Ramezani
1
Mohammad Reza Saberi
2
G. Ali Mansoori
3
School of Pharmacy, Mashhad University of Medical Science, Mashhad, Iran.
Department of Medicinal Chemistry, School of Pharmacy & Avicenna Pharmaceutical Research Center, Mashhad University of Medical Science, Mashhad, Iran.
Departments of Bio & Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60607-7052 USA.
Diamondoids are cage-like saturated hydrocarbons consisting of fused cyclohexane rings. The Diamondoids family of compounds is one of the best candidates for molecular building blocks (MBBs) in nanotechnology to construct organic nanostructures compared to other MBBs known so far. The challenge is to find a route for self-assembly of these cage hydrocarbons and their applications in the bottom-up synthesis. In this paper, a DNA-based self-assembly technique called “DNA Bridge-based Self-assembly” (DBS) is introduced to self-assemble the diamondoid molecules based upon a bottomup strategy. The results of our computations and simulations with different molecular mechanical force fields (MM+, AMBER, BIO+, and OPLS) and different optimization algorithms (Polak-Ribiere, Fletcher- Reeves, and block-diagonal Newton-Raphson) furthermore confirm the feasibility of the formation of such hybrid nanoarchitecture.
https://www.ijnnonline.net/article_4002_d7972677cf8c5fc1d627056e9a0aaf62.pdf
Diamondoids
DNA Bridge-based Self-assembly (DBS)
Self-assembly
Bottom-up synthesis
DNA Nanotechnology
eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
37
44
4003
Palladium nanoparticles synthesis using polymeric matrix: poly(ethyleneglycol) molecular weight and
palladium concentration effects
P. Ahmadian Namini
1
A. A. Babaluo
2
B. Bayati
3
Nanostructure Materials Research Center (NMRC), Sahand University of Technology
Nanostructure Materials Research Center (NMRC), Sahand University of Technology Research Center of Polymeric Materials, Sahand University of Technology,
Research Center of Polymeric Materials, Sahand University of Technology
Due to unique applications of palladium nanoparticles, synthesis of these nanoparticles by a simple and low cost method is very important. In this work, Pd nanoparticles were synthesized with narrow size distribution by loading metal salt (Pd(OAc)2 ) into the polymeric matrix (PEG) as reducing agent and stabilizer. Also, the effect of metal salt concentration and PEG molecular weight on the conversion of Pd 2+ to nano Pd 0 and synthesized palladium nanoparticles morphology were investigated by UV-vis spectroscopy, XRD and TEM. The UV results confirmed the significant effect of PEG molecular weight on the reduction reactivity of polymeric matrix. Also, TEM and XRD results revealed that metal salt concentration has significant effect on the synthesized Pd nanoparticles size.
https://www.ijnnonline.net/article_4003_c36b8e4dbfa736310d3f9180422b4e13.pdf
Palladium
Nanoparticle
Reduction
Polymeric matrix
eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
45
52
4004
Structural and optical properties of n- type porous silicon– effect of etching time
N. Jeyakumaran
1
B. Natarajan
2
S. Ramamurthy
3
V. Vasu
4
Department of Physics, VHNSN College, Virudhunagar – 626001, Tamilnadu, India.
Department of Physics, Sethu Institute of Technology, Kariapattii – 626106, Tamilnadu, India
Department of Physics, Gandhigram Rural University, Gandhigram – 624302, Tamilnadu, India
Department of Physics, Madurai Kamaraj University College, Madurai – 625 002, Tamilnadu, India
Porous silicon layers have been prepared from n-type silicon wafers of (100) orientation. SEM, FTIR and PL have been used to characterize the morphological and optical properties of porous silicon. The influence of varying etching time in the anodizing solution, on structural and optical properties of porous silicon has been investigated. It is observed that pore size increases with etching time and attain maximum for 20 minutes and then decreases. The PL spectrum peak shifts towards the higher energy side, which supports the quantum confinement effect in porous silicon. The FTIR shows that the Si-Hn peaks are observed at the surface of the PS layer and these chemical species also give raise the PL in PS.
https://www.ijnnonline.net/article_4004_1220d4905dc4039b93b28b55e61e5ed9.pdf
Band gap
Etching time
Hydrogen bonds
Porous Silicon
Porosity
Peak intensity
Luminescence
Quantum confinement
eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
53
62
4005
Synthesis, optical and structural characterization of CdS nanoparticles
Sh. Jamali
1
E. Saievar-Iranizad
2
S. Farjami Shayesteh
3
Physics department, Guilan University, Rasht I. R. Iran
Physics department, School of Basic Science, Tarbiat Modares University, Tehran, I. R. Iran
Physics department, Guilan University, Rasht I. R Iran
Cadmium sulfide nanoparticles were grown using wet chemical method by dissolving the reactants of cadmium acetate and sodium sulfide in the presence of thioglycerol (TG) as capping agent in ethanol solvent. Different nanoparticle sizes and size distribution were obtained through varying the molarities of thioglycerol. At higher TG concentration, synthesis provides a nearly monodisperse nanoparticles. Also this method reveals high stability of nanoparticles in ethanol solvent. Samples properties were investigated using UV-VIS absorption, photoluminescence spectroscopy and X-ray diffraction (XRD) methods
https://www.ijnnonline.net/article_4005_433eb1ecfd8b053e66d1a3457d5c01af.pdf
Cadmium Sulfide
nanoparticles
Chemical Synthesis
Photoluminescence (PL)
Aging
effect
Hexagonal structure
eng
Iranian Nanotechnology Society
International Journal of Nanoscience and Nanotechnology
1735-7004
2423-5911
2007-12-01
3
1
63
68
4006
Synthesis of polyvinyl pyridine/C60 conjugates in supercritical carbon dioxide*
N. Bhullar
1
M. G. H. Zaidi
2
S. Alam
3
R. Singh
4
Department of Chemistry, G.B. Pant University of Agriculture & Technology Pant Nagar Uttaranchal 263145 India ,
Department of Chemistry, G.B. Pant University of Agriculture & Technology Pant Nagar Uttaranchal 263145 India
Polymer Division Defense Materials Research Development & Establishment DMSRDE Kanpur208 013 UP India.
Directorate of Extramural Research and Intellectual Property Rights, D.R.D.O. Bhawan ,New Delhi, 110011. India
In the present investigation efforts have been made to synthesis polyvinyl pyridine (PvPy) /C60 conjugates through 2, 2-azobisisobutyronitrile (AIBN) initiated insitu polymerization of PvPy in scCO2.The process of synthesis was monitored under different reaction conditions ranging 1200-1800psi, 60-90 oC over 6 hours. The progress of polymerization was monitored rheoviscometrically. The concentration of PvPy and AIBN ranging 6.95-20.85*10-3 and 304.50-931.50 *10-3 afforded PvPy/C60 conjugates in the yield (%) ranging 10.30-48.8. Selected PvPy/C60 conjugates were characterized through UV-VIS spectra, scanning electron microscopy, gel permeation chromatography and solution rheoviscometery.
https://www.ijnnonline.net/article_4006_79e6226b9e4ccaf3e95db02f1a58e1f5.pdf
Supercritical carbon dioxide
Synthesis
C60/ polyvinyl pyridine conjugates
Rheoviscosity
Spectra
Electron microscopy