scholarly journals Pengaruh Jumlah Polimer terhadap Karakteristik Fisik dan Pelepasan Nanopartikel Fraksi Diterpen Lakton Sambiloto - Kitosan

2020 ◽  
Vol 7 (2) ◽  
pp. 99
Author(s):  
Retno Sari ◽  
Abhimata Paramanandana ◽  
Dewi Isadiartuti ◽  
Annisa Maulidia Rahayyu

Fraksi diterpen lakton dari Andrographis paniculata Nees (sambiloto) (FDTLS) memiliki kandungan utama andrografolid. andrografolid diketahui memiliki bioavailabilitas buruk, bersifat sangat lipofilik, dan memiliki kelarutan yang rendah di dalam air. Penjebakan bahan sukar larut ke dalam polimer hidrofilik seperti kitosan dapat memperbaiki disolusi yang selanjutnya akan meningkatkan bioavailabilitas dan efektivitasnya. Tujuan penelitian ini adalah untuk meningkatkan disolusi serta mengetahui pengaruh jumlah kitosan terhadap karakteristik fisik, efisiensi penjebakan dan pelepasan FDTLS dari nanopartikel FDTLS-kitosan. Nanopartikel dibuat dengan metode gelasi ionik-semprot kering menggunakan tripolifosfat sebagai penyambung silang. Nanopartikel dibuat dengan rasio FDTLS-kitosan yang berbeda, yaitu 1:2 (FK1), 1:2,5 (FK2) dan 1:3 (FK3). Evaluasi yang dilakukan meliputi morfologi, pemeriksaan differential thermal analysis (DTA), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), efisiensi penjebakan, dan uji pelepasan. Nanopartikel yang dihasilkan berbentuk sferis dan FK2 mempunyai permukaan paling halus dengan entalpi paling tinggi. Difraktogram nanopartikel FDTLS-kitosan menunjukkan perubahan kristalinitas menjadi lebih amorf. Efisiensi penjerapan FDTLS dalam nanopartikel kitosan sebesar 29,01-32,69%. Hasil uji pelepasan nanopartikel menunjukkan peningkatan kecepatan FDTLS terlarut sebesar 1,6 kali dibandingkan dengan substansi FDTLS. Dari hasil penelitian dapat disimpulkan bahwa pembentukan nanopartikel dengan polimer kitosan dengan metode gelasi ionik-semprot kering dapat meningkatkan jumlah FDTLS terlarut.

1996 ◽  
Vol 11 (3) ◽  
pp. 703-715 ◽  
Author(s):  
H. C. Zeng

The PbO/MoO3 system with 47%: 53%, 53%: 47%, and 50%: 50% molar ratios at various processing temperatures has been studied with x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential thermal analysis (DTA) methods. It is found that in addition to the crystallization of primary PbMoO4 phase, subphases such as Pb2MoO5 and PbMo2O7 are also formed. The remaining PbO and MoO3 are detected at certain stages of the thermal process due to localized powder inhomogeneity. Physical processes, such as sublimation, eutectic melting, solid to liquid, and liquid to vapor transformations are also investigated. In particular, evaporations of excessive PbO or MoO3 in the nonstoichiometric PbO/MoO3 can be correlated to thermal processing parameters. The current study has led to the following three processing guidelines to obtain stoichiometric PbMoO4: (i) for high temperature application, such as the Czochralski melt growth, it is suggested an excessive MoO3 (a few mol %) must be included and a slow heating rate should be employed; (ii) for low temperature synthesis, the stoichiometric PbO–MoO3 can be used, but with a fast heating rate; and (iii) PbO-rich PbO/MoO3 system is not recommended in PbMoO4 synthesis.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


2019 ◽  
Vol 70 (8) ◽  
pp. 2747-2752
Author(s):  
Constantin Marutoiu ◽  
Ioan Bratu ◽  
Mircea Gelu Buta ◽  
Olivia Florena Nemes ◽  
Sergiu Petru Timbus(Monk Siluan) ◽  
...  

A two-sided wooden icon from a monastery in Transylvania was submitted for multidisciplinary investigations involving X-Ray Fluorescence, Radiographic Photographyand Fourier Transform Infrared Spectroscopy. The most important part of the icon is St. Nicholas wooden icon, painted over forty years ago. The spectroscopic methods used revealed the painting materials composition, the status of the wooden stage, and the presence of resins as varnish (Fourier Transform Infrared Spectroscopy). On one side, the St Nicholasicon was painted over an old icon, St. Arch. Michael, which was evidenced by X-Ray Photography. The obtained data can serve for the preservation and the restoration of these wooden icons.


2021 ◽  
pp. 152808372110592
Author(s):  
Vahid Shakeri Siavashani ◽  
Gursoy Nevin ◽  
Majid Montazer ◽  
Pelin Altay

Flexible sensors and wearable electronics have become important in recent years. A good conductive and flexible textile is needed to develop a commercial wearable device. Conductive polymers have generally been used with limitation in reducing the surface resistance to a certain amount. In this research, a method for fabricating a stretchable highly conductive cotton/lycra knitted fabric is introduced by treating the fabric with polypyrrole (PPy), silver nanoparticles (SNPs) composites, and post-treating with poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) (PEDOT:PSS). Polypyrrole and SNPs were in situ fabricated on the cotton/lycra fabric by consecutive redox reaction of silver nitrate and pyrrole and finally covered by PEDOT:PSS solution through dip-coating. The coated textile was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray mapping, and energy dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy confirmed PPy-SNPs (P-S) composites on the fabric surface. Fourier transform infrared spectroscopy results, X-ray mapping, EDAX, and XRD analysis also confirmed the P-S composites and PEDOT:PSS polymeric layer on the fabric. Morphological observation showed a layer of PEDOT:PSS on the P-S caused the higher connection of coating on textiles which resulted in the higher electrical conductivity (43 s/m). Also morphological observations showed penetration of the silver particles inside fibers which represented improving in attachment and stability of the coating on the fibers. Further, the electrical conductivity of PPy-SNPs-PEDOT:PSS coated textile increased under the tension. Hence, the stretchable and highly conductive knitted cotton/lycra fabric has potentiality to be used for fabricating the flexible sensors or wearable electronics.


Author(s):  
S. J. Pradeeba ◽  
K. Sampath

This research was carried out based on the significance of protecting the environment by preventing the contamination of water caused from effluents discharge from dyeing industries, effective nanocomposite were prepared to solve this problem. The poly(azomethine), ZnO, and poly(azomethine)/ZnO nanocomposites were prepared and characterized by Fourier transform-infrared spectroscopy, ultraviolet (UV)–visible spectroscopy, powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), scanning electron Microscope (SEM), and transmission electron microscopy (TEM) techniques. Methylene blue (MB), Malachite green (MG), and Bismarck brown (BB) were degraded from water using poly(azomethine) (PAZ), zinc oxide (ZnO), PAZ/ZnO (PNZ) nanocomposites as photocatalyst in the presence of natural sunlight. The degradation efficiency and reaction kinetics were calculated, and the outcome of the photocatalytic experiments proved that the PAZ/ZnO nanocomposites reveals excellent photocatalytic activity and effective for decolorization of dye containing waste water than PAZ and ZnO in the presence of natural sunlight. The maximum degradation efficiency 97%, 96%, and 95% was obtained for PNZ nanocomposites at optimum dosage of catalyst as 500 mg and 50 ppm of MB, MG, and BB dye concentration, respectively. The maximum degradation time was 5 h. After photocatalytic study, the samples were characterized by Fourier-transform infrared spectroscopy (FT-IR) and UV–visible spectroscopy.


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