47 research outputs found
Spectroscopic, Structural, and Morphology of Nickel Oxide Nanoparticles Prepared Using <i>Physalis</i> <i>angulata</i> Leaf Extract
No full textGreen synthesis of nickel oxide nanoparticles (NiO NPs) usingPhysalisangulataleaf extract (PALE) as weak base sources and stabilizing agents has been reported. Chemical bonding and vibration spectroscopy, crystallographic structure, optical band gap, particle size and microscopic studies of NiO NPs were also investigated. Ni-O vibration modes of NiO NPs were analyzed by FTIR and Raman instrument at ~400 and ~900 cm-1wavenumber. XRD pattern of NiO NPs confirmed cubic crystal structure with space groupFm-3m.Optical band gap of NiO NPs determined by using Tauc plot method was about 3.42 eV. Particle size analyzer showed size distribution of NiO NPs was 64.13 nm which confirm NiO formed in nanoscale. Electron microscopic studies of NiO NPs were observed by using scanning electron microscopy and transmission electron microscopy.</jats:p
Extraction of Sungkai (Peronema cannescens Jack) leaves, Antioxidant Activity Test and Its Nanoemulsion Formulation
No full textSungkai (Peronema canescens J.) is an Indonesian native plant widely distributed on the islands of Kalimantan and Sumatra. Potential of these plants is related to the presence of secondary metabolites, which can be obtained through extraction. In its application, plant extract requires a delivery system that can penetrate well into the skin and maximise the efficacy of the active ingredients, such as nanoemulsion, which has high kinetic stability due to the smaller droplet size. The research was conducted to compare the yields from the two extraction methods, the presence of active compounds in the plants related to their properties as antioxidants and then formulated into nanoemulsion. The results showed that Sungkai leaves extract contains active metabolites such as alkaloids, flavonoids, tannins and saponins. The extraction of sungkai leaves yields 15.91% and 14.71% for CE and UAE methods. The total phenolic and flavonoid values were 27.74 and 41.88 mg GAE/g extract; 17.60 and 36.02 mg QE/g extract; and IC50 values of 50.78 and 53.50, included in the strong antioxidant category. Stable nanoemulsion formulation was obtained by adding 1 gram of olive oil with a homogenisation speed of 15000 rpm, with particle size of 83.4 nm and a polydispersity index of 0.455
Modifikasi Bentonit Terpilar Al dengan Polianilin Sebagai Reduktor Ion Cr (VI)
Get PDFBentonit merupakan salah satu mineral yang kelimpahannya cukup besar di Indonesia. Untuk meningkatkan daya guna bentonit maka dibuat bentonit terpilar Al dengan polianilin dan diaplikasikan sebagai agen pereduksi ion Cr(VI). Pengukuran dengan XRD menunjukkan pilarisasi dengan polikation Al menyebabkan basal spacing dari bentonit naik menjadi 18,41413 Ã…. Sintesis Bent@Al@PANI dilakukan secara in situ dengan perbandingan konsentrasi APS/anilin adalah 1,25. Hasil uji FTIR dan spektrofotometer UV-Vis mengindikasikan bahwa polianilin yang diperoleh merupakan bentuk emeraldin salt (ES). Dari pengolahan data persentase 0,1 g Bent@Al@PANI 0,05 M dengan waktu reaksi 10 menit, pH 3,0 mampu mereduksi Cr(VI) 1,92x10-4 M sebesar 89,92%.
Kata kunci: bentonit, basal spacing, reduksi Cr(VI), polianili
Facile green preparation of Y2O3 decorated with ZnFe2O4 using citrus limon (L.) osbeck leaf extract for photocatalytic degradation of malachite green
No full textThe Y2O3 decorated with ZnFe2O4 was successfully synthesized using Citrus limon (L.) Osbeck leaf extract for the first time. A modification of Y2O3 with ZnFe2O4 nanoparticles was carried out because Y2O3 is stable but has a wide band gap, making it less active in visible light. On the other hand, ZnFe2O4 has a small band gap and is cheap. The synthesized ZnFe2O4/Y2O3 nanocomposites, ZnFe2O4, and Y2O3 nanoparticles were characterized using FTIR, XRD, TEM, SEM, and DRS UV–Vis. TEM and DRS UV–Vis results show that the ZnFe2O4/Y2O3 nanocomposite particle has a size of 49,61 nm with a unique shape and an optical band gap of 2.08 eV. The photocatalytic activity of Y2O3, ZnFe2O4, and ZnFe2O4/Y2O3 was observed based on the photodegradation of malachite green (MG) dye under visible light. The results demonstrate that ZnFe2O4/Y2O3 can degrade MG with a photodegradation percentage of 95 % within 120 min, which is better than pure ZnFe2O4 and Y2O3. After the fourth cycle, the photodegradation percentage of MG by ZnFe2O4/Y2O3 remained at 88 %, demonstrating good reusability of ZnFe2O4/Y2O3 for photocatalytic degradation. These findings demonstrate that the use of ZnFe2O4 as a modifier may increase the photocatalytic performance of Y2O3
Microwave-Assisted Synthesis of Alginate-Stabilized Gold Nanoparticles
Get PDFAn efficient and rapid method for preparation of Au nanoparticles (Au-NP) has been developed by direct microwave irradiation of metal precursor and alginate mixed solution in a single step. Here, alginate molecules act as both the reducing and stabilizing agents of Au-NP. The obtained nanoparticles were characterized by ultraviolet-visible (UV-Vis) spectroscopy, particle size analyzer, fourier transform infrared spectroscopy, and transmission electron microscopy. The nanoparticles have a spherical form and perfectly capped with alginate when using alginate and chloro auric acid (HAuCl4) precursor in the concentration range of 0.50 to 0.75% (w/v) and 0.40 mM, respectively. The use of a lower concentration of alginate and/or higher concentration of HAuCl4 caused agglomeration to occur, thereby resulting in a bigger size of Au-NP and red shifting of surface plasmon resonance (SPR) peak to a higher wavelength
The Synthesis of Alginate-Capped Silver Nanoparticles under Microwave Irradiation
Get PDFSynthesis of silver nanoparticles (Ag-NP) was successfully performed within a few minutes by microwave irradiation of the precursor salt (AgNO3) and alginate mixed solution in one pot. Herein, alginate molecules acted as both a reducing and stabilizing agent for the preparation of the silver nanoparticles. The obtained nanoparticles were characterized by ultraviolet-visible (UV-Vis) spectroscopy, particle size analysis (PSA), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The pH and concentration ratio of the alginate/metal precursor salt greatly influenced the particle size and its distribution of Ag-NP. The higher the pH the higher the nucleation rate and the larger the electrostatic stabilization, while both of them were responsible for producing a smaller particle size and a narrower size distribution. A higher concentration ratio also yielded a smaller particle size and a narrower size distribution, but above the optimum ratio, the trend was conversely changed due to the reducing capability of the alginate, which was dominant above the optimum ratio, thus creating a high density of nuclei, allowing aggregation to occur. A lower ratio not only led to a higher tendency to produce larger particles, but also a higher probability of anisotropic particle shape formation due to the lack of reducing capability of the alginates
Green Synthesis of Gold Nanoparticles using Aqueous Garlic (Allium sativum L.) Extract, and Its Interaction Study with Melamine
Get PDFGold nanoparticles (AuNPs) have been successfully prepared by green synthesis method using aqueous extract of garlic with the Latin name of Allium sativum L. (ASL) as a reducing and stabilizing agents. Identification of active compounds in aqueous ASL extract was conducted by phytochemical analysis and Fourier transform infrared (FTIR) spectroscopy, while the synthesized AuNPs were characterized using UV-Vis spectrophotometer and transmission electron microscopy-selected area electron diffraction (TEM-SAED). The AuNPs formation was optimized at aqueous ASL extract concentration of 0.05%, HAuCl4 concentration of 2.0×10-4 M, and pH of 3.6. The optimized AuNPs was characterized using TEM, and has a spherical shape with particle size of 15±3 nm. The particles were also stable up until one month. The synthesized AuNPs has been studied its interaction with melamine, and showed the optimum pH of interaction at 3.6
A facile and effective technique for the synthesis of thiol-modified Au/alginate nanocomposite and its performance in stabilizing Pickering emulsion
No full textAbstractSynthesis of thiol-based ligand-modified Au/alginate was successfully performed using simple, facile and effective technique, with the aid of microwave irradiation for completing the reduction of gold precursor. The nanocomposite has lower hydrophilicity compared to that of unmodified Au/alginate, as shown by the decrease in surface tension and increase in contact angle to water. Type and concentration of thiol-based ligand greatly influenced the hydrophilicity. By employing mercaptoundecanoic acid (MUA) and dodecanethiol simultaneously as thiol-based ligand modifier for Au/alginate, the as-prepared nanocomposites have the capability to stabilize Pickering O/W (oil-in-water) emulsion of chloroform in water. Nanocomposite concentration and pH significantly affected emulsification capability and emulsion stability
Effect of Concentration of Imperata Cylindrica L Leaf Extract on Synthesis Process of Gold Nanoparticles
Get PDFGold Nanoparticles (GoldNPs) successful was performed using HAuCl4 precursor as Au3+ ion source with 7x10-4 M concentration. The research aims to knows effect of concentration variation of Imperata cylindrica L leaf extract on synthesis process of gold nanoparticles. The research used of green synthesis method. Colloid of nanoparticles which is formed in analyzed using UV-Vis Spectrophotometer, FT-IR Spectroscopy, PSA, PZC, XRD and TEM. The results of synthesis showed the best concentration of Imperata cilindrica L leaf extract at 3,46%, happen a shift of wavelength at UV-Vis from 216 nm to 530 nm with 1.779 absorbance value. The PSA analysis showed a particle size of 51.87 nm and a PZC value of -19.2 mV. The result of FT-IR indicated a shift of wavenumber in the hidroxyl group from 3354 cm-1 to 3390 cm-1 and showed a interaction of hydroxyl group at imperata cylindrica L leaf extract with Au3+ ion. TEM analysis shows the morphology of GoldNPs that spherical shape with a particle size of 20 nm. XRD calculation results show crystallite size of gold nanoparticles is 15.47 nm
