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All Journal ALCHEMY Jurnal Penelitian Kimia
Sayekti Wahyuningsih
Program Studi Kimia, Fakultas MIPA, Universitas Sebelas Maret Surakarta
Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Environmental Science Materials Science & Nanotechnology

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Composite of Chitosan Vanilin / Sulfonated Polystyrene As Polymer Electrolyte Membranes: Cationic Exchange Capacity, Swelling Degree And Thermal Properties Edi Pramono; Candra Purnawan; Yuniawan Hidayat; Jati Wulansari; Sayekti Wahyuningsih
ALCHEMY Jurnal Penelitian Kimia Vol 10, No 2 (2014): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.10.2.55.116-129

Abstract

Research on the preparation and characterization of sulfonated polystyrene (PST) /chitosan vanillin (KV) composite as electrolyte membranes has been conducted in order to investigate the effect of PST and KV composition  to its chemical and physical properties. Polystyrene was modified by sulfonation reaction to produces PST, meanwhile chitosan was modified by schift base reaction to produces KV. The composite membranes were prepared by casting method and were characterized in order to identify the functional groups contained in the composite, the cation exchange capacity (CEC), the Swelling Degree (SD), the thermal properties and the morphology. The peak of imine vibration in the FTIR spectrum indicates that the chitosan vanilin was succesfully synthesized. Meanwhile, the peak of sulfonate vibration indicates the product of sulfonation on polystyrene. The result of CEC analysis shows that the addition of sulfonate groups on polystyrene and the addition of phenolic groups on chitosan increase the CEC value. The increasing of PST and KV concentration in membrane enhance the CEC value. However, the increasing of PST concentration in membrane composition even decrease the Swelling Degree of membranes. Meanwhile, the increasing of KV concentration increase the swelling degree of membranes. Thermal analysis shows that the thermal decomposition of membranes occurs in three stages i.e. the dehydration of water molecules, the degradation of the subtituen groups and the plasticizer and the degradation of the back bone of chitosan and polystyrene.
Optimizing of TiO2 Separation from Bangka Ilmenite by Leaching Process Using HCl Sayekti Wahyuningsih; Hari Hidayatullah; Edi Pramono
ALCHEMY Jurnal Penelitian Kimia Vol 10, No 1 (2014): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.10.1.16.54-68

Abstract

Separation of titanium dioxide (TiO2) from ilmenite Bangka has been done byleaching processusing HCl. Before the leaching process, ilmenite was roastedat 900oC for pre-oxidation (preliminary - oxidation). Leaching process carried out by variation of HCl concentration and Fe0 reducing agents. While the re-deposition of dissolved Ti4+ ion achieved by hydrolysis - condensation using 2-propanol-H2O solvents. Leaching the pre-oxidazed ilmenite shows the phase change of  pseudobrokite (Fe2TiO5) into hematite (Fe2O3) and synthetic rutile (TiO2). Formation of the synthetic rutile was characterized by the loss of intensity of Fe2TiO5 at 26.65º and the increasing intensity of rutile TiO2 at 27.49º.The dissolution rate of both titanium and iron was found to be increased, generally, by increasing acid concentration in case of HCl as well as by increasing ilmenite: Fe0 ratio. Precipitation of the dissolved titania with 2-propanol -H2Oof 8:2(v /v) produced anatase TiO2 due to the hydrolysis and condensation of Ti-tetra isopropoxide complexes.
Co-Authors Candra Purnawan Edi Pramono Hari Hidayatullah Jati Wulansari Yuniawan Hidayat