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"ABSTRAKPolianilin telah disintesis melalui polimerisasi oksidatif kimia dengan Ammonium Peroksidisulfat APS sebagai inisiator dalam berbagai konsentrasi 50 g/L, 100 g/L dan 200 g/L . Polimerisasi anilin berjalan dengan ditandai adanya kenaikan temperatur karena reaksi yang terjadi dalam larutan mencapai temperatur tertinggi sebesar 42 C pada larutan dengan konsentrasi APS 200 g/l. Hasil dari reaksi polimerisasi oksidatif berupa basa emeraldin PANi-EB . Struktur PANi dikonfirmasi dengan FTIR ditandai dengan adanya vibrasi stretching pada cincin benzenoid dan quinoid pada bilangan gelombang 1400-1500 cm-1. Sifat konduktif PANi diperoleh melalui pemberian protonasi menggunakan asam kuat yaitu HCl dan HClO4. Nilai konduktivitas PANi-EB mengalami peningkatan 102 kali setelah doping menggunakan HCl dan 106 kali pasca doping HClO4. Semua PANi hasil sintesis memiliki kemampuan penyerapan gelombang elektromagnetik pada rentang frekuensi 10 GHz-15 GHz. Semakin tinggi nilai resistivitas PANi yaitu makin rendah nilai konduktivitas, semakin tinggi juga nilai reflection loss RL . Nilai RL tertinggi sekitar -18 dB pada frekuensi 12,5 GHz dan 14,3 GHz diperoleh dari PANi-EB hasil polimerasi dengan konsentrasi APS sebesar 200 g/l.

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ABSTRAKPolianiline has been synthesized by chemical oxidative polymerization using Ammonium Polyaniline has been synthesized through chemical oxidative polymerization with Ammonium Peroxidisulfate APS as an initiator in various concentrations 50 g l, 100 g l and 200 g l . The polymerization reactions of aniline are characterized by an increase in temperature due to the reaction occurring in the solution, reaching the highest temperature of 42 C in a solution with APS concentration of 200 g l. Result of oxidative polymerization reaction is the emeraldine base polyaniline or PANi EB. The PANi formation was confirmed by FTIR which characterized by stretching vibrations in benzenoid and quinoid rings at wave numbers 1400 1500 cm 1 respectively. The conductive property of PANi was obtained through doping by a protonation using strong acids HCl and HClO4. It was found that conductivity value PANi EB increased 102 times after doping with HCl and 106 times after doping with HClO4. Moreover, all synthesized PANi has the ability to absorb electromagnetic waves in the frequency range 10 GHz 15 GHz. The higher the resistivity value of PANi that is the lower the conductivity value, the higher the reflection loss RL . The highest RL values of about 18 dB at 12.5 GHz and 14.3 GHz frequencies were obtained from PANi EB polymeration results with APS concentrations of 200 g l."

"Penelitian ini dilakukan untuk membuat material nanokomposit magnetik berbahan dasar stronsium heksaferit (SrFe12O19 atau SHF) dan besi kobalt (FeCo) sebagai Radar Absorbing Material (RAM). Telah dibuat nanokomposit (SrFe12O19)1-x.(FeCo)x melalui metode mechanical milling dengan variasi x=0; 0.3 dan 0.5. Komposit dibuat menggunakan nano SHF dan paduan FeCo. FeCo diperoleh dari reduksi karbon nano CoFe2O4 pada temperatur 1100°C selama 3 dan 5 jam disertai dengan quenching. Karakterisasi magnet diambil dengan pengujian Permagraf dan VSM. Karakterisasi fasa didapatkan dengan uji XRD. Pengujian VNA dilakukan untuk mendapat nilai reflection loss (RL) sehingga dapat diketahui persentase serapan nanokomposit yang terbentuk.

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This research purpose is to make a magnetic nanocomposite material based on strontium hexaferrite (SrFe12O19 or SHF) and iron-cobalt (FeCo) as a Radar Absorbing Material (RAM). Nanocomposites following the composition of (SrFe12O19)1-x.(FeCo)x through mechanical milling method with x=0; 0,3 and 0,5 has been made. The composites are based on nano SHF and FeCo alloy. The FeCo alloy was synthesized via carbon reduction of nano CoFe₂O₄ in 1100°C with various holding time of 3 and 5 hours, with quenching applied after annealing. Magnetic characterization was gained through Permagraph and VSM testing. The phases of the nanocomposites gained through XRD testing. VNA testing was done to gain reflection loss (RL) value so the absorbtion percentage of the created nanocomposite can be calculated."