scholarly journals The potential of green seaweed (Caulerpa sp.) extract to synthesis ZnO nanoparticles with zinc nitrate as a precursor and pH variations

2021 ◽  
Vol 924 (1) ◽  
pp. 012088
Author(s):  
R N Sari ◽  
E Sinurat ◽  
D L Ayudiarti ◽  
D A Oktavia

Abstract The potential of green seaweed Caulerpa sp. as a reducing agent, stabilizer, and capping agent and the benefits of zinc oxide (ZnO) nanoparticles in the food and non-food is exciting to be developed. The research was aimed to understand the potential of green seaweed (Caulerpa sp.) to become ZnO nanoparticles capping agent with ten mM zinc nitrate as a precursor and pH variations of 8-12. The analysis included function groups, particle size distribution, and % mass O and Zn composition. The result found that spectra at wave number 574 cm−1 were Zn-O stretching vibration from solution pH synthesis of 11. Size distribution was homogeneous, but it still had not met the size of nano. The average particle size ranged from 992.37-1369.36 nm, and the smallest particle size was obtained at a ZnO synthesized at a pH of 8. The composition from ZnO synthesis at solution pH of 9 was 7.68% O and 92.32% Zn. Caulerpa sp. extract could produce a synthesis of ZnO with ten mM zinc nitrate as a precursor and solution pH variations. Although the biosynthesis had not produced a ZnO with nanoparticles size yet, the particle size distribution had been homogeneous. The biosynthesis at pH 9, %mass Zn and O for ZnO produced had been similar to the ZnO standard.

2015 ◽  
Vol 151 ◽  
pp. 282-287 ◽  
Author(s):  
A. Escobedo-Morales ◽  
D. Téllez-Flores ◽  
Ma. de Lourdes Ruiz Peralta ◽  
J. Garcia-Serrano ◽  
Ana M. Herrera-González ◽  
...  

2015 ◽  
Vol 1130 ◽  
pp. 273-277 ◽  
Author(s):  
M. Zaki Mubarok ◽  
Robi S. Sulistyo ◽  
Siti Khodijah Chaerun ◽  
W.P. Minwal

This paper discusses the results of indirect bioleaching test works of nickel laterite ore by the assistance of Aspergillus niger. Series of metabolic acid biogeneration shake-flask experiments were performed to investigate the effects of substrate type, nitrogen and phosphate dosages, the presence of magnesium and manganese salts, as well as aeration of the culture media on the effectiveness of the metabolic acid biogeneration. The investigation results showed that after 16 days of incubation, the solution pH of 1.44 was obtained from the acid biogeneration using cassava starch as carbon source in the presence of 0.1% (w/w) KH2PO4, 1% (w/w) (NH4)2SO4 and 0.25 g/L of MgSO4 under aerated condition. Leaching experiments of limonite and saprolite ore samples were carried out by using the generated metabolic acids at various ore particle size distributions, solid to liquid ratio and temperature. The highest nickel extraction percentage of 88.9% was obtained from the leaching of saprolite ore at 95°C, stirring speed of 400 rpm, particle size distribution of-80+100 mesh, solid to liquid ratio of 4.65 g/mL after 240 minutes, while that of 84.9% was obtained from the leaching of limonite ore at 95°C, stirring speed of 400 rpm, particle size distribution of-80 +100 mesh and solid-liquid ratio of 5.2 g/ml after 1440 minutes. The leaching of saprolite ore by using the biogenerated acids was selective to magnesium, with co-extracted Mg of only 1.5% after 24h of the agitation leaching test.


2016 ◽  
Vol 88 (1-2) ◽  
pp. 43-60 ◽  
Author(s):  
Khang Wei Tan ◽  
Siah Ying Tang ◽  
Renjan Thomas ◽  
Neela Vasanthakumari ◽  
Sivakumar Manickam

AbstractCurcumin has been found to possess significant pharmaceutical activities. However, owing to its low bioavailability, there is a limitation of employing it towards clinical application. In an attempt to surmount this implication, often the choice is designing novel drug delivery systems. Herein, sterically stabilized nanoscale dispersion loaded with curcumin (nanodispersion) based on non-ionic colloidal system has been proposed. In this study, the process conditions were effectively optimized using response surface methodology (RSM) with Box–Behnken design (BBD). The suggested optimum formulation proved to be an excellent fit to the actual experimental output. STEM images illustrate that the optimal curcumin-loaded nanodispersion has spherical morphology with narrow particle size distribution. Particle size distribution study confirms that the solution pH does not affect the nanodispersion, and physical stability study shows that the colloidal system is stable over 90 days of storage at ambient conditions. More importantly, controlled release profile was achieved over 72 h and the in vitro drug release data fit well to Higuchi model (R2=0.9654).


2017 ◽  
Vol 898 ◽  
pp. 1885-1891 ◽  
Author(s):  
Bei Gang Li ◽  
Min Wang

Fly ash (FA), a kind of fine-powder solid waste, was utilized to prepare a novel Fe/chitosan/FA composite (Fe/CTS/FA) by the calcination and solution reaction with chitosan (CTS) and ferric iron. In combination with the adsorption for reactive turquoise blue KN-G (RTB KN-G) and direct sky blue 5B (DSB 5B) dyes, the main conditions of preparation and adsorption of Fe/CTS/FA were investigated. The composite was characterized with SEM, EDS, particle-size distribution and N2-gas adsorption-desorption technology. The results show that: (1) Fe/CTS/FA prepared by calcining FA at 500°C and further mixing reaction with CTS and FeCl3⋅6H2O solution according to the mass ratio of m(FA):m(CTS):m(Fe)=10:1:0.34 has excellent adsorption properties. The amount of adsorption is mainly affected by solution pH and reaches the equilibrium in 60 min for high-concentration RTB KN-G and DSB 5B dye wastewater with adsorption capacities of 892.95 mg/g and 615.65 mg/g, which are 16.28 and 32.56 times larger than those of FA, respectively. (2) The characterization results of Fe/CTS/FA indicate that CTS and iron hydroxides have been successfully loaded on FA. The surface morphology of Fe/CTS/FA is significantly changed, and the particle-size distribution is obviously smaller than that of FA.


2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda

1995 ◽  
Vol 5 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Christine M. Woodall ◽  
James E. Peters ◽  
Richard O. Buckius

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