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All Journal Reaktor IPTEK Journal of Proceedings Series IPTEK The Journal for Technology and Science Bulletin of Chemical Reaction Engineering & Catalysis
Widiyastuti Widiyastuti
Institut Teknologi Sepuluh Nopember
Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Energy Materials Science & Nanotechnology

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Journal : IPTEK Journal of Proceedings Series

 1 
Controlled Morphology of Silica Particle by Spray Drying Method Albar, Abdurrahman Anis; Widiyastuti, Widiyastuti; Setyawan, Heru
IPTEK Journal of Proceedings Series No 6 (2020): 6th International Seminar on Science and Technology 2020 (ISST 2020) - IN-PRESS
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2020i6.11118

Abstract

The controlled morphology of mesoporous silica particle with colloidal silica as precursor solution was investigated using spray drying method. The colloidal silica solution was made from sodium silicate (waterglass) using sol-gel method. The operating condition of spray dring such as precursor solution volumetric rate and hot air flowrate was varied to study the effect of the silica particle’s morphology. Two-fluid nozzle was used as atomizer with volumetric rate ranged from 1.6 mL/min to 5 mL/min, and hot air heated from tubular furnace with flowrate ranged from 210 L/min to 414 L/min, both resulting doughnut-like shape with more doughnut fraction with increased volumetric rate. With the increase of volumetric rate from 1.6 mL/min to 5 mL/min, the surface area and total pore volume are tend to decrease (168.234 to 131.001 m2/g and 0.1652 to 0.1251 cc/g respectively). Meanwhile, for increasing hot air flowrate from 210 L/min to 414 L/min, the surface area are tend to increase (135.353 to 168.234 m2/g) but total pore volume tend to decrease (0.1921 to 0.1652 cc/g).
Synthesis of PVA/SiO2 Nanofibers by Electrospinning Method for Supercapacitor Separators Muhamad Nirwan; Heru Setyawan; Widiyastuti Widiyastuti
IPTEK Journal of Proceedings Series No 6 (2020): 6th International Seminar on Science and Technology 2020 (ISST 2020)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2020i6.11119

Abstract

In this research, polyvinyl alcohol (PVA)/silica nanofibers have been synthesized using electrospinning technique. Solutions of sodium silicate (Na2SiO3) in water and PVA flakes were blended and then processed by electrospinning method to obtain PVA/silica nanofibers. The effect of silica concentration on the resulting morphology and diameter of as-spun nanofibers were investigated by using scanning electron microscopy (SEM). The electrolyte uptake and retention of the as-spun nanofibers were measured. The silica concentration has an effect on the resulting nanofibers, where an increase in silica concentration resulted in a decrease on the diameter of the fibers. The manufactured nanofibers have an average diameter of 200-300 nm. The electrolyte uptake and retention values are also affected by the concentration of the silica in the electrospun solution, with the electrolyte uptake and retention values decreasing with the increase in silica concentration. The best values obtained are 151% for electrolyte uptake and 60% for electrolyte retention, which shows potential for PVA/silica nanofibers as an alternative material for supercapacitor separators.
The Effect of Furnace Temperature and Precursor Concentration Ratio to The Characteristics of Nanocomposite ZnO-Silica Iva Maula; Widiyastuti Widiyastuti; Tantular Nurtono; Fadlilatul Taufany; Siti Machmudah; Sugeng Winardi
IPTEK Journal of Proceedings Series Vol 1, No 1 (2014): International Seminar on Applied Technology, Science, and Arts (APTECS) 2013
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2014i1.323

Abstract

Zinc Oxide is a semiconductor with relatively non-toxic, cheap and abundant properties which can be applied to LEDs. ZnO colloids are unstable due to further chemical reactions and coagulation so the addition of silica is needed to inhibit the growth of ZnO. ZnO was synthesized using sol-gel method by hydrolyze zinc acetate dihydrate in ethanol solution. Silica colloids was prepared by dissolving waterglass in distilled water at a temperature of 60 °C then passed into cation resin that has been activated using 2N HCl for ion exchange with Na+ to H+. In this study, the spray drying method was used to produce ZnO-silica nanocomposite. Morphological characterization of particles formed was analyzed using Scanning Electrostatic Microscope (SEM) (Zeiss Evo MA LS, Cambridge, England). X-Ray Diffraction (XRD) (Cu-Kα 1.54 A0, 40 kV, 30 mA, X’pert Pro, PAN alytical, Netherlands) and Fourier Transform Infrared (FTIR) (Therniscientific Nicolet iS10, US) were used to analyze the crystallinity and group functionalization, respectively. The results show that more particles are formed on 10% concentration volume of ZnO colloids rather than 5%.
Synthesis of Composite Graphene/ Fe3O4 by Electrophoretic Deposition Using Pulse Direct Current Ervina Rumpakwakra; Hariyati Purwaningsih; Widiyastuti Widiyastuti; Heru Setyawan
IPTEK Journal of Proceedings Series No 6 (2020): 6th International Seminar on Science and Technology 2020 (ISST 2020)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j23546026.y2020i6.11101

Abstract

Composites Graphene/Fe3O4 have been successfully synthesized by the electrophoretic deposition method using pulse direct current (PDC) on a nickel foam substrate. In this study, we synthesized graphene and Fe3O4 separately before the two materials were composited. We synthesize graphene from coconut shell charcoal and synthesize Fe3O4 from pure iron. Graphene and Fe3O4 which have been formed, are dissolved with demineralized water as a dispersing medium so that a solution of 1.5 mg / mL is obtained which is then compiled layer by layer on the surface of the substrate with variations in deposition time of 10 to 30 minutes at room temperature. This aims to determine the effect of deposition time on the formation of graphene/Fe3O4 composites. The results showed that the use of PDC was able to precipitate graphene/Fe3O4 composites on the surface of the substrate. The use of longer deposition time, results in more graphene/Fe3O4 composites which adhere to the substrate surface. This result is also supported by XRD testing which shows the longer the deposition time, the diffraction peaks appear sharper.
Co-Authors Abdul Halim Adhi Setiawan Agung Nugroho Agung Nugroho Ajiz, Hendrix Abdul Albar, Abdurrahman Anis Delyana Ratnasari Ervina Rumpakwakra Fadlilatul Taufany Fahmi Fahmi Hariyati Purwaningsih Heru Setyawan Iva Maula Lizda Johar Mawarani Muhamad Nirwan Ni Made Intan Putri Suari Nora Amelia Novitrie Sahara Tulaini Siti Machmudah Tantular Nurtono Winardi, Sugeng