scholarly journals Effect of pH and Irradiation Power in the Synthesis of Gold Nanoparticles by using Binahong (Anredera cordifolia) Leaves Extract

2021 ◽  
Vol 37 (2) ◽  
pp. 476-483
Author(s):  
Foliatini F ◽  
Nurdiani N
Keyword(s):  
Irradiation Time ◽  
Low Ph ◽  
Microwave Oven ◽  
Nano Particles ◽  
Total Power ◽  
Truncated Form ◽  
Nonspherical Particle ◽  
Clear Explanation ◽  
Irradiation Power ◽  
Experimental Parameters

Au nano particles have been successfully synthesized using extract of binahong (Anredera cordifolia) leaves at various pH, irradiation power and irradiation time. The synthesis was conducted using microwave oven for some minutes, at certain adjusted experimental condition. pH of solution was varied from 2 – 10, irradiation power was adjusted in the range of 30% - 100% of total power of 800W, and iiradiation time was studied in the range of 30 – 120 second. The experimental results showed at low pH, the nonspherical particle was more commonly formed. The stabilization of particles took place more effectively at the higher pH. At low pH, the nano particles were below 50 nm in size and were in form of triangle, rod, rhombic, cubic, or truncated form of these shapes. UV-Vis spectra also indicated that both microwave irradiation power and time significantly affect the morphology of particles. These research provide clear explanation about the effect of the pH and irradiation time over the AuNP synthesis by using greener method, which can be further studied in optimizing experimental parameters for conducting industrial scale synthesis.

scholarly journals Otimização da produção de biodiesel a partir de óleo de coco babaçu com aquecimento por microondas

2018 ◽  
Vol 39 (4) ◽  
pp. 37
Author(s):  
Ulisses Magalhães Nascimento ◽  
Antonio Carlos Sales Vasconcelos ◽  
Eduardo Bessa Azevedo ◽  
Fernando Carvalho Silva
Keyword(s):  
Microwave Heating ◽  
Irradiation Time ◽  
Reaction Times ◽  
Coconut Oil ◽  
Microwave Oven ◽  
Raw Material ◽  
Biodiesel Production ◽  
Experimental Conditions ◽  
Domestic Microwave Oven ◽  
Central Composite

Reactions under microwave heating present reduced reaction times and larger yields. Therefore, this work is aimed at adapting a domestic microwave oven and optimizing the transesterification reaction used in biodiesel production with microwave heating, using babaçu coconut oil as raw material. It was used a central composite design for varying irradiation time, KOH concentration, and oil:methanol ratio. Statistical analyses were performed in orderto assess the significance of the model used. The optimized experimental conditions were: oil:methanol ratio, 8.59; KOH concentration, 2.19 %; and irradiation time, 70 seconds, givingan yield of approximately 100% regarding esters formation.

Position Controlled Growth in Carbon Nanotubes Catalyzed by an Iron Nano-dot Array

2005 ◽  
Vol 900 ◽  
Author(s):  
Jun-ichi Fujita ◽  
Takahito Mukawa ◽  
Satoshi Okada ◽  
Ryota Kobayashi ◽  
Masahiko Ishida ◽  
...  
Keyword(s):  
Electron Beam ◽  
Carbon Nanotube ◽  
Position Control ◽  
Irradiation Time ◽  
Chemical Vapor ◽  
Ethanol Vapor ◽  
Nano Particles ◽  
Control Technique ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth

ABSTRACTWe report a successful demonstration of a position control technique for carbon nanotube growth catalyzed by an iron nano-dot array, which was fabricated by using electron beam induced chemical vapor deposition (EB-CVD). Point irradiation of an electron beam with ferrocene source gas produced an amorphous carbon dot containing iron atoms that were uniformly dispersed into each dot, and its position could be precisely controlled. Vacuum annealing of the ferrocene based dots induced segregation of iron nano-particles, whose size was almost proportional to the beam irradiation time. After removing the carbon residue, an ethanol CVD process carried out at 800°C under 40 mmHg of ethanol vapor induced carbon nanotube growth from the dots. Many grown nanotubes were very thin, being 0.7 to 1.8 nm in diameter. These diameters were much less than that of the bottom iron particles.

Synthesis of P(AA-AM)/ Organic Montmorillonite Super Absorbent Resin under Focused Signal-Mode Microwave Irradiation

2013 ◽  
Vol 746 ◽  
pp. 137-141
Author(s):  
Shui Li Lai ◽  
Ying Hua Gao
Keyword(s):  
Microwave Irradiation ◽  
Cetyltrimethylammonium Bromide ◽  
Irradiation Time ◽  
Single Mode ◽  
Synthesis System ◽  
Organic Montmorillonite ◽  
Irradiation Power ◽  
Aqueous Solution Polymerization ◽  
Signal Mode ◽  
Irradiation Technology

A super absorbent resin (SAR) of acrylic acid (AA)/acrylamide (AM) /organic montmorillonite (OMMT) composite was synthesized by aqueous solution polymerization. This process was carried out under precision microwave organic synthesis system and its single-mode focusing microwave irradiation technology was studied. The montmorillonite (MMT) was modified by treating with cetyltrimethylammonium bromide. Moreover, the factors that effect on liquid absorbency rate of the SAR were discussed, such as neutralization degree (ND) of AA, microwave irradiation time, microwave irradiation power and the dosage of the OMMT. It gave the best liquid absorbency rate (1520g.g-1 and 165g.g-1 in purified water and 0.9wt% NaCl solution, respectively).

Surface Modification of Alumina Nano-Particles by UV-Induced Grafting Polymerization of 2-Hydroxyethyl Methacrylate

2010 ◽  
Vol 93-94 ◽  
pp. 95-98 ◽  
Author(s):  
K. Yantaboot ◽  
S. Maensiri ◽  
Paveena Khansawai ◽  
Sittipong Amnuaypanich
Keyword(s):  
Uv Irradiation ◽  
Irradiation Time ◽  
Nano Particles ◽  
Hydroxyethyl Methacrylate ◽  
Alumina Surface ◽  
Sequential Method ◽  
Grafting Polymerization ◽  
Alumina Particles ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Alumina nano-particles was grafted with poly(2-hydroxyethyl methacrylate) (PHEMA) utilizing the sequential method; that is, the alumina surface was first rendered with initiator, benzophenone, by UV-irradiation followed by the grafting polymerization of HEMA on the surface which was initiated thermally and propagated via the free-radical polymerization. FT-IR spectroscopy confirmed the successful grafting of PHEMA onto the alumina surface. Determined by thermalgravimetry (TG), the amount of benzophenone on the alumina surface was found to increase with the UV-irradiation time; however upon grafting of PHEMA, the amount of grafted-PHEMA was the same irrespective of the reaction time. The glass transition temperature (Tg) of grafted-PHEMA on alumina particles was approximately 93 °C that is higher than that of PHEMA which has Tg around 85 °C. This indicates the more restricted movement of grafted-PHEMA compared with the ungrafted-PHEMA.

scholarly journals A Green Synthesis of a Novel Calix[4]Resorcinarene from 7-Hydroxycitronellal Using Microwave Irradiation

2018 ◽  
Vol 18 (1) ◽  
pp. 53
Author(s):  
Ratnaningsih Eko Sardjono ◽  
Iqbal Musthapa ◽  
Iis Rosliana ◽  
Fitri Khoerunnisa ◽  
Galuh Yuliani
Keyword(s):  
Energy Consumption ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Irradiation Time ◽  
Microwave Oven ◽  
Conventional Heating ◽  
Heating Method ◽  
Microwave Assisted ◽  
Domestic Microwave Oven ◽  
Waste Production

A new versatile macromolecule cyclic C-3,7-dimethyl-7-hydroxycalix[4]resorcinarene (CDHHK4R) has been synthesized from a fragrance agent, 7-hydroxycitronellal, via microwave irradiation. The reaction utilized a domestic microwave oven at various irradiation time and power to yield an optimum condition. As a comparison, the conventional heating method was also employed for the synthesis of the same calix[4]resorcinarene. Compared to the conventional method, microwave-assisted reaction effectively reduced the reaction time, the amount of energy consumption and the waste production. It is found that the synthesis of CDHHK4R by microwave irradiation yielded 77.55% of product, higher than by conventional heating which was only 62.17%.

Preparation of Polymer Suppressant in Coal Transportation under Single Mode Microwave Irradiation

2012 ◽  
Vol 198-199 ◽  
pp. 19-22
Author(s):  
Shui Li Lai ◽  
Ying Hua Gao ◽  
Qiang Chai
Keyword(s):  
Acrylic Acid ◽  
Microwave Irradiation ◽  
Irradiation Time ◽  
Weight Ratio ◽  
Single Mode ◽  
Solution Polymerization ◽  
Oxidized Starch ◽  
Irradiation Power ◽  
Aqueous Solution Polymerization ◽  
Radiation Time

The aqueous solution polymerization of acrylic acid, acrylamide and oxidized starch under single mode microwave irradiation was studied, and a polymer suppressant was synthesized. The factors that influence on performance of the polymer suppressant were discussed, including microwave irradiation time, neutralization degree of acrylic acid (AA), the dosage of oxidized starch. The polymer suppressant was characterized by IR and scanning electron microscopy (SEM). Results indicated that the optimal synthetic conditions are as follows: microwave irradiation power, 300 W; radiation time, 2 mins; 50% neutralization degree of the AA; m(AA) : m(AM) : m(oxidized starch)= 5.0 : 3.3 : 3.4, weight ratio initiator in the feed is 0.4%, respectively.

scholarly journals Change of phase from ?-Bi2O3 to ?-Bi2O3 using the ceramic microwave-assisted approach and its increase of capacitance

2019 ◽  
Vol 32 ◽  
pp. 14-21
Author(s):  
Alejandro Elizarraras Peñaloza ◽  
Miriam Estrada Flores ◽  
Carmen Magdalena Reza San Germán ◽  
Lucía Graciela Díaz Barriga Arceo ◽  
Patricia Santiago Jacinto ◽  
...  
Keyword(s):  
Energy Demand ◽  
Irradiation Time ◽  
Power Level ◽  
Microwave Oven ◽  
Capacitance Measurement ◽  
X Ray Diffraction ◽  
Ceramic Method ◽  
X Ray ◽  
Before And After ◽  
Short Times

The use of microwaves for the synthesis of materials is very important due to its versatility, it is an economical option, friendly with the environment, generates a low energy demand and the syntheses are carried out in very short times. There are many methods that use microwaves to obtain materials, however, the simplest one is the ceramic method, which consists in blending by grinding the reagents or precursors, which are placed in a quartz cell and finally carried to the microwave oven for synthesis. The reagents used to carry out this research are ?-Bi2O3 and graphite. The phase change in the ?-Bi2O3 was obtained despite the differences in weight composition and the variation of power level and irradiation time inside the microwave oven. X-ray diffraction and scanning electron microscopy were used to verify the phase and morphology of the samples before and after irradiation. The last step of this work was the capacitance measurement of the composites made of 0.39 g of alumina and 0.01 g of the product of graphite and bismuth oxide after irradiation at different conditions. The results demonstrated an increasing of capacitance in all the samples conformed by ?-Bi2O3/C/Al2O3.

scholarly journals Synthesis and Environmental Application of BiOI/BiOCl Composites

2014 ◽  
Vol 11 (2) ◽  
pp. 469-476
Author(s):  
Baghdad Science Journal
Keyword(s):  
Methyl Orange ◽  
Room Temperature ◽  
Irradiation Time ◽  
Reducing Power ◽  
Experimental Conditions ◽  
Environmental Application ◽  
Experimental Parameters ◽  
Organic Precursors ◽  
Degradation Of Methyl Orange ◽  
Visible Light Photocatalytic

This work illustrates an enhanced visible light photocatalytic degradation of methyl orange dye (M.O.) by employing BiOI / BiOCl composites prepared under room temperature and without any organic precursors. Various experimental parameters have been studied, namely; composition of the composite, irradiation time and cell material. Composition D which implied 75% BiOI and 25% BiOCl has shown the highest bleaching of M.O. dye. This confirms the optimum photo-sensitization phenomenon for this composition in comparison to others. In the optimum photo-sensitized composite the electron of the conduction band reveals better reducing power and the hole of the valence band exhibits more oxidative power than those of pure BiOI electron and hole. Accordingly, under appropriate experimental conditions, methyl orange was significantly bleached using composite D.

Preparation of Ru Nanoparticles Supported on Al[sub 2]O[sub 3] by Using Conventional Microwave Oven: Effect of Irradiation Power

2011 ◽  
Author(s):  
Ari Sulistyo Rini ◽  
Shahidan Radiman ◽  
Mohd. Ambar Yarmo ◽  
Muhammed Hasan Aslan ◽  
Ahmet Yayuz Oral ◽  
...  
Keyword(s):  
Microwave Oven ◽  
Ru Nanoparticles ◽  
Irradiation Power
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