Indriana Kartini
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara, Yogyakarta 55281

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Synthesis of Silver-Chitosan Nanocomposites Colloidal by Glucose as Reducing Agent Endang Susilowati; Triyono Triyono; Sri Juari Santosa; Indriana Kartini
Indonesian Journal of Chemistry Vol 15, No 1 (2015)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (466.175 KB) | DOI: 10.22146/ijc.21220

Abstract

Silver-chitosan nanocomposites colloidal was successfully performed by chemical reduction method at room temperature using glucose as reducing agent, sodium hydroxide (NaOH) as accelerator reagent, silver nitrate (AgNO3) as metal precursor and chitosan as stabilizing agent. Compared to other synthetic methods, this work is green and simple. The effect of the amount of NaOH, molar ratio of AgNO3 to glucose and AgNO3 concentration towards Localized Surface Plasmon Resonance (LSPR) absorption band of silver nanoparticles was investigated using UV-Vis spectrophotometer. The stability of the colloid was also studied for the first 16 weeks of storage at ambient temperature. The formation of silver nanoparticles was confirmed by the appearance of LSPR absorption peak at 402.4–414.5 nm. It is also shown that the absorption peak of LSPR were affected by NaOH amount, ratio molar AgNO3/glucose and concentration of AgNO3. The produced silver nanoparticles were spherical with dominant size range of 6 to 18 nm as shown by TEM images. All colloidals were stable without any aggregation for 16 weeks after preparation. The newly prepared silver-chitosan nanocomposites colloidal may have potential for antibacterial applications.
The Effect of Caramelization and Carbonization Temperatures toward Structural Properties of Mesoporous Carbon from Fructose with Zinc Borosilicate Activator Tutik Setianingsih; Indriana Kartini; Yateman Arryanto
Indonesian Journal of Chemistry Vol 14, No 3 (2014)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (595.66 KB) | DOI: 10.22146/ijc.21236

Abstract

Mesoporous carbon was prepared from fructose using zinc borosilicate (ZBS) activator. The synthesis involves caramelization and carbonization processes. The effect of both process temperature toward porosity and functional group of carbon surface are investigated in this research. The caramelization was conducted hydrothermally at 85 and 100 °C, followed by thermally 130 °C. The carbonization was conducted at various temperatures (450–750 °C). The carbon-ZBS composite were washed by using HF 48% solution, 1M HCl solution, and aquadest respectively to remove ZBS from the carbon. The carbon products were characterized with nitrogen gas adsorption-desorption method, FTIR spectrophotometry, X-ray diffraction, and Transmission Electron Microscopy. The highest mesopore characteristics is achieved at 100 °C (caramelization) and 450 °C (carbonization), including Vmeso about 2.21 cm3/g (pore cage) and 2.32 cm3/g (pore window) with pore uniformity centered at 300 Å (pore cage) and 200 Å (pore window), containing the surface functional groups of C=O and OH, degree of graphitization about 57% and aromaticity fraction about 0.68.
Characterization and Photocatalytic Activity of TiO2(rod)-SiO2-Polyaniline Nanocomposite Sri Wahyuni; Eko Sri Kunarti; Respati Tri Swasono; Indriana Kartini
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (666.302 KB) | DOI: 10.22146/ijc.22550

Abstract

A study of TiO2(rod)-SiO2 composites coated with polyaniline (PANI) has been performed. PANI was synthesized through in-situ polymerization of aniline at various concentration (0.0137, 0.0274, and 0.0411 M) on the composite under acidic condition. PANI was confirmed by the appearance of C=N, C=C vibrations and the redshift of the band-gap from 3.14 eV for the TiO2(rod)-SiO2 into 3.0 eV for the TSP01 composite. It is also shown that the polymerization does not change the crystal structure of TiO2(rod)-SiO2 as confirmed by the XRD pattern. The TEM image shows a mixed structure of SiO2 coated by TiO2(rod)-PANI layers and the oxides coated by PANI layers. Therefore, the surface area of the resulted TiO2(rod) and the composites did not change significantly. The T TiO2(rod)-SiO2-PANI composite give small improvement under visible irradiation from 20.25 to 25.59% (around 5% from the bulk of TiO2(rod)) and from 25.03 to 25.59% (around 2% from TiO2(rod)-SiO2 composite). The mixed structure of the composites, as well as the formation of excessive layers of PANI, are possibly the case for the low photoactivity. Further improvement to obtain a core-shell structure with a thin layer of PANI is still sought.