scholarly journals Formulasi dan Karakterisasi Nanopartikel Kafein Hasil Isolasi dari Biji Kopi Robusta

2021 ◽  
Vol 7 (1) ◽  
pp. 47-59
Author(s):  
Yunida Yunida ◽  
Muhammad Totong Kamaluddin ◽  
Theodorus Theodorus ◽  
Sonlimar Mangunsong
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Sustained Release ◽  
Vinyl Alcohol ◽  
Glycolic Acid ◽  
Polydispersity Index ◽  
Poly Vinyl Alcohol ◽  
Transmission Electron ◽  
Particle Size Analyzer

Kopi robusta merupakan jenis kopi yang paling banyak dikembangkan oleh petani di Indonesia. Kopi kaya akan zat bioaktif yang memberikan manfaat bagi kesehatan, salah satunya adalah kafein. Namun, konsumsi kafein dalam jumlah berlebihan juga dapat menimbulkan efek samping. Salah satu upaya untuk meminimalkan efek samping dan menghasilkan sediaan sustained release adalah dengan membuat formulasi kafein dalam bentuk sediaan nanopartikel. Dalam penelitian ini dilakukan ekstraksi, isolasi dan identifikasi kafein dari biji kopi robusta. Dari 200 gram biji kopi robusta diperoleh kristal kafein sebanyak 0,83 gram. Hasil identifikasi secara mikroskopis diperoleh morfologi kristal kafein seperti jarum-jarum panjang dan karakteristik kristal kafein mirip dengan kafein standar. Preparasi nanopartikel kafein dilakukan menggunakan metode single emulsion-solvent evaporation dengan pembawa PLGA (Poly-(Lactic-co-Glycolic Acid)) dan PVA (Poly(Vinyl Alcohol)) sebagai stabilizer. Karakterisasi preparat nanopartikel menggunakan PSA (Particle Size Analyzer) memberikan hasil diameter ukuran partikel 183,9 nm, nilai PDI (Polydispersity Index) 0,113 dan zeta potensial -13,5 mV. Penentuan morfologi menggunakan Transmission Electron Microscopy diperoleh partikel yang berbentuk bulat (spheris).  

Radiation – induced preparation of polyaniline/poly vinyl alcohol nanocomposites and their properties

2019 ◽  
Vol 107 (8) ◽  
pp. 725-735
Author(s):  
Hoda H. Saleh ◽  
Rehab Sokary ◽  
Zakaria I. Ali
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Vinyl Alcohol ◽  
Oxidative Polymerization ◽  
Nanocomposite Films ◽  
Poly Vinyl Alcohol ◽  
Transmission Electron ◽  
Scanning Electron

Abstract Polyaniline (PANI) nanoparticles and PANI/poly vinyl alcohol (PVA) nanocomposite films were synthesized by the oxidative polymerization of aniline and ammonium peroxodisulfate (APS), as an oxidizing agent in aqueous medium. The PANI/PVA nanocomposite films were exposed to γ-irradiation after oxidative polymerization. Synthesized polyaniline (PANI) nanoparticles and PANI/PVA nanocomposite films were characterized by attenuated total reflectance infrared spectroscopy (FTIR-ATR), X-ray diffraction, high resolution scanning electron microscopy, (HRSEM) high resolution transmission electron microscopy, (HRTEM) and UV-VIS absorption spectroscopy. Energy band gap of PANI nanofibers was determined from Tauc’s plots which equal 4.2 eV. Scanning electron microscopy images show that chemically synthesized of polyaniline has nanofibers structure and irradiated PANI/PVA nanocomposite have a mixture of nanorod and nanosphere structures. The transmission electron microscopy show that chemically synthesized of polyaniline has average length in the range 34 ± 10 nm with less wide distribution, where as the irradiated PANI/PVA nanocomposite has coreshell structure.

Preparation and Characterization of Monodisperse Ceria Microspheres

2010 ◽  
Vol 434-435 ◽  
pp. 850-852
Author(s):  
Qi Wang ◽  
Bo Yin ◽  
Zhen Wang ◽  
Gen Li Shen ◽  
Yun Fa Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Electron Microscope ◽  
Crystalline Form ◽  
X Ray ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Scanning Electron

In present work, ceria microspheres were synthesized by template hydrothermal method. Crystalline form of the as-synthesized ceria microspheres was defined by X-ray powder diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Dispersibility of ceria microspheres was comprehensively characterized using scanning electron microscope (SEM) observation and laser particle size analyzer. Furthermore, the ultraviolet light absorption performances of ceria microspheres with several different sizes were compared by ultraviolet visible spectrophotometer. The results showed that ceria microspheres presented excellent UV absorbent property and the size influence was remarkable.

scholarly journals Optimasi Formula Submikro Partikel Poly (Lactic-co-Glycolic Acid) Pembawa Betametason Valerat dengan Variasi Konsentrasi Poly (Vinyl Alcohol) dan Waktu Sonikasi

2018 ◽  
Vol 5 (1) ◽  
pp. 55
Author(s):  
Mardiyanto Mardiyanto ◽  
Najma Anuria Fithri ◽  
Winesfin Raefty
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Classification System ◽  
Glycolic Acid ◽  
Poly Vinyl Alcohol ◽  
Diffusion Cell ◽  
Franz Diffusion Cell ◽  
Transmission Electron ◽  
Biopharmaceutics Classification

Preparasi betametason valerat (BMV) ke dalam submikro partikel bertujuan untuk mengatasi permasalahan kelarutan (Biopharmaceutics Classification System II) dan meningkatkan kemampuan penetrasi pada kulit. Metode emulsion solvent evaporation digunakan dalam mempreparasi BMV yang terenkapsulasi oleh polimer PLGA (Poly Lactic-co-Glycolic Acid) dan stabilizer PVA (Poly Vynil Alcohol). Proporsi komponen formula optimum yang didapatkan yaitu konsentrasi PVA 50 mg dan waktu sonikasi 10 menit dengan nilai respon %EE 73,000%, pH 4,800, dan %kadar BMV pada uji stabilitas 62,057%. Hasil analisis diameter, PDI (Poly Dispersity Index), dan zeta potensial formula optimum yang dihasilkan masing-masing sebesar 342,700 nm, 0,104, dan -12,200 mV. Penentuan morfologi partikel menggunakan alat Transmission Electron Microscopy menunjukkan bentuk hampir sferis. Pengujian penetrasi partikel dilakukan melalui uji difusi secara in vitro, menggunakan alat Franz Diffusion Cell. Hasil uji difusi menunjukkan nilai persen terdifusi tertinggi pada submikro partikel PLGA-BMV (23,067% ± 0,055) dibandingkan dengan zat aktif murni (18,007% ± 0,002), dan sediaan BMV yang berada di pasaran (19,506 ± 0,071). Analisis laju disolusi menunjukkan submikro partikel PLGA-BMV (84,211% ± 1,943) meningkatkan proses pelepasan obat dibandingkan BMV murni (10,912% ± 0,246). Laju pelepasan dan mekanisme pelepasan PLGA-BMV mengikut orde nol. 

scholarly journals Aplikasi Teknologi Nanoenkapsulasi sebagai Delivery System Fitobiotik Alami untuk Ternak

2019 ◽  
Vol 2 (2) ◽  
pp. 91-95
Author(s):  
Umi Maesaroh ◽  
Nanung Danar Dono ◽  
Zuprizal Zuprizal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Delivery System ◽  
Target Organ ◽  
Transmission Electron ◽  
Particle Size Analyzer

Teknologi nanoenkapsulasi merupakan suatu teknologi penyalutan partikel dimana memiliki diameter ukuran dari mikrometer sampai nonometer yang menggunakan suatu bahan enkapsulan khusus hingga membuat partikel tersebut mempunyai sifat fisikokimia yang diinginkan. Dalam sistem pengantaran komponen bioaktif fitobiotik pada target organ, nanoenkapsulasi berperan sebagai pembawa (carrier) senyawa bioaktif yang ada di dalam matriksnya. Nanopartikel memiliki ukuran yang sangat kecil akan tetapi luas permukaan untuk proses terjadinya reaksi kimia lebih lebar, sehingga menjadikan pencernaan dan pemanfaatan nutrien dalam tubuh ternak lebih optimal. Penelitian ini bertujuan untuk mengetahui karakteristik dari nanoenkapsulasi fitobiotik alami untuk ternak. Karakteristik dari nanenkapsulasi fitobiotik alami diteliti dengan menggunakan metode gelasi ionik antara ekstrak daun sirsak, kitosan dan STPP. Parameter yang diamati yaitu karakteristik nanoenkapsulasi ekstrak daun sirsak (NEDS) meliputi ukuran partikel, morfologi, dan zeta potensial. Ukuran partikel dan potensial zeta diamati dengan menggunakan particle size analyzer (PSA), dan morfologi nanopartikel diamati dengan menggunakan transmission electron microscopy (TEM). Hasil penelitian menunjukkan bahwa NEDS memiliki ukuran sebesar 234,00 ± 21,5 nm, dengan morfologi berbentuk bulat, dan muatan zeta potensial sebesar 38,20 ± 1,93 mV.Kata kunci : nanokapsulasi, fitibiotik, daun sirsak, kitosan

Study on Synthesis of PVA Stabilized Silver Nanoparticles using Green Synthesis and Their Application for Catalysis

2012 ◽  
Vol 1453 ◽  
Author(s):  
Ja Young Cheon ◽  
Won Ho Park
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Reaction Temperature ◽  
Ag Nanoparticles ◽  
Vinyl Alcohol ◽  
Reaction Rate ◽  
Poly Vinyl Alcohol ◽  
Transmission Electron

ABSTRACTThe parameters influencing the formation of silver nanoparticles are reported. We used poly(vinyl alcohol) (PVA), maltose and silver nitrate as stabilizer, reductant and silver nanoparticles precursor, respectively. The formation of nanoparticles depended upon reaction temperature and pH of solution. The pH of solution controlled by HCl and NaOH. The reaction rate and amount of nanoparticles increase with increasing the reaction temperature. Also, formation of nanoparticles are influenced by pH. The size distribution and dispersion of Ag nanoparticles formed in PVA solution were observed by Transmission electron microscopy (TEM) and the reaction rate and amount of nanoparticles were characterized UV-vis spectrophotometer.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Introduction of Nanoscale Porous Aromatic Frameworks in PTMSP Matrix

2020 ◽  
Vol 869 ◽  
pp. 28-39
Author(s):  
Danila Bakhtin ◽  
Leonid Kulikov ◽  
Alexander Malakhov ◽  
Stepan D. Bazhenov
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Ir Spectroscopy ◽  
Suzuki Reaction ◽  
Main Idea ◽  
Polymeric Materials ◽  
Transmission Electron ◽  
Porous Aromatic Framework ◽  
Porous Aromatic Frameworks

Samples of nanoscale nano-PAF-10 and nano-PAF-24 porous aromatic framework-like polymeric materials were synthesized using the Suzuki reaction in a microemulsion. Monomers were tetrakis-(p-bromophenyl)methane and 1,4-phenylenediboronic acid. The main idea of the approach is to use 1,4-phenylenediboronic acid not only as a direct participant in the reaction, but also as a surfactant, which allows to stabilize the drops of the emulsion. Using this procedure, samples of PAF-like polymers were synthesized from the mixture, containing the mixture of tetrakis(p-bromophenyl)methane and 1,4-phenylenediboronic acid in ratio from 1:2 to 1:6; the reaction was conducted from 10 to 24 hours. The resulting materials were characterized by IR spectroscopy, NMR spectroscop. To estimate the particle size of the obtained materials, transmission electron microscopy was used. The object of the study were polymers, that were synthesized in 10-hour and 24-hour reactions. The particle size in the first material was in the range of 3-10 nm, in the second - from 30 to 100 nm.

Novel Methods for Preparation and Surface Treatment of Nano-CaCO3

2013 ◽  
Vol 750-752 ◽  
pp. 336-339
Author(s):  
Fa Chao Wu ◽  
Teng Fei Shen
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Fourier Transform ◽  
Room Temperature ◽  
Transmission Electron ◽  
Reduce Energy Consumption ◽  
Scanning Electron

In this work, CaCO3 nanoparticles have been synthesized via heat-treatment of a new precursor. Effect of calcinations temperature on particle size has been investigated. The products were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). nanoCaCO3 was modified using chloroform as solvent and fatty acid as modifier atroom temperature. The advantage of this modification is that it can be proceed at room temperature and it can reduce energy consumption.

scholarly journals Gold Particle Size Determination on Au/TiO2-CeO2 Catalysts by Means of Carbon Monoxide, Hydrogen Chemisorption and Transmission Electron Microscopy

2009 ◽  
Vol 5 ◽  
pp. 13-23 ◽  
Author(s):  
C. Guzmán ◽  
Gloria Del Angel ◽  
Ricardo Gómez ◽  
F. Galindo ◽  
R. Zanella ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Monoxide ◽  
Particle Size ◽  
Gold Particle ◽  
Precipitation Method ◽  
Hydrogen Chemisorption ◽  
Gold Particles ◽  
Transmission Electron ◽  
Gold Particle Size

Au/TiO2 and Au/TiO2-CeO2 catalysts were prepared by the sol-gel method and carbon monoxide, hydrogen chemisorption and TEM spectroscopy have been exploited to determine the size of gold particles. The gold nanoparticles (8.1 to 2.1 nm) were deposited by using the deposition-precipitation method. The XRD characterization shows the presence of anatase as the TiO2 crystalline phase; while by XPS spectroscopy, the presence of Au°, Au2O3, Ce3+ and Ce4+ species co-existing in the Au/TiO2-CeO2 catalysts is shown. The characterizations by TPD-CO as well as by TPD-H2 (temperature programmed desorption) showed that on catalysts containing cerium, the gold particle size can be determined with great accuracy by using these chemisorption methods. The gold particle size calculated from either the CO or H2 thermodesorption values is in good agreement with that obtained by High Resolution Transmission Electron Microscopy (HRTEM) and Scanning Transmission Electron Microscopy (STEM) analyses. It was proposed that the TPD-CO and/or TPD-H2 techniques could be helpful for the characterization of the gold particles by TEM; especially when the high contrast in the pictures of the supports containing CeO2 prevents the particle size from being determined.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

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