Hasil Pencarian  ::  Simpan CSV :: Kembali

"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.

---

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."

"Strontium hexaferrite dengan komposisi nominal Sr0.6Fe,-<,..,jMn,TiyO, (x =0, y=; x = 0.4, y= 0.6; x = 0.5, y = 0.5; x = 0.6, y =0.4) disintesa dengan reaksi keadaan padat. Empat komponen serbnk BaCO,, SrCO,, Fe,O,, MnCO,, dan TiO, dicampur menggunakan High Energy Milling selama 10 jam dan disinterring pada 1050'C dalam tekanan atrnosfer selama 15 jam dan pendinginan eli tungku pemanas. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometer (VSM) dan network analyzer digunakan untuk analisa struktur, sifat elektomagnetik dan penyerapan gelombang. Hasil memperlihatkan bahwa identifikasi fasa dengan penghalusan pola difrkasi XRD diperoleh fasa tunggal untuk substitusi Mn-Ti terhadap Sr0.6Fe,o, dengan x ~ y dan multi fasa terbentuk untnk x " y. Analsis mikrostrnktur dengan SEM menunjukkan variasi partikel adalah 2 - 5 um. Evaluasi terhadap karakteristik magnetik mengindikasikan bahwa terjadi penurunan koersifitas dengan kenaikan substitusi ion Mn2+ dan Ti4+ tetapi penurunan yang signifikan diperoleh terhadap saturasi magntetisasi pada substitusi Mn dan Ti dengan x :t: y. Penelitian saat ini menunjukkan penyerapan gelombang, reflection dan transmission dan juga reflection loss pada rentang frekuensi 7-16 GHz. Dilaporkan juga performansi penyerapan pada substitusi Mn dan Tipada strontium hexaferrite.

---

Strontium hexaferrite with nominal compositions Sr0.6Fe,-{"':Y~xTiy03 (x ~ 0, y o=Q; x ~ 0.4, y ~ 0.6; x ~ 0.5, y ~ 0.5; x ~0.6, y ~ 0.4) have been synthesized by solid state reaction. The four components powder were BaCO,, S!CO,, Fe,O,, MnCO,, and Ti02 mixed with High Energy Milling for 10 hours and sintered at I 050'C in the air at atmosphere pressure for 15 hour and furnace cooling. X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), resonance vibrating sample magnetometer (R· VSM) and vector network analyzer were used to analyze its structure, electromagnetic and microwave absorption properties. The result showed that, phase identification by refinement results ofXRD pattern confirmed single phase was obtained for Mn-Ti substituted Sr0.6Fe20, with x ~ y and multiphase formed for x" y. The microstructure analyses by SEM showed that the varied particle sizes of 2 -- 5 ~-tm. Evaluation on the magnetic characteristic indicated that coercivity decreased as the number ofMn2"~" and Ti +ions increased but significant decrease in saturation magnetization obtained for Mn and Ti substitution with x ::1:- y. Present investigation demonstrates that microwave absorber. reflection and transmission as well as reflection loss in the frequency range 7-16 GHz were derived Absorption performance ofMn and Ti substituted strontium hexaferrite are also reported."

"Material magnet permanen seperti heksaferit dapat dimodifikasi sifatnya menjadi material penyerap radar dengan cara mensubstitusi parsial ion-ion besinya dengan ion lain untuk menurunkan medan koersivitasnya (Hc) tanpa penurunan magnetisasi remanen (Mr) yang signifikan. Material heksaferit yang banyak digunakan umumnya berupa barium heksaferit (BaFe12O19) dan stronsium heksaferit (SrFe12O19) yang memiliki karakteristik magnetik yang hampir sama. Penelitian terbaru menunjukkan bahwa substitusi barium heksaferit dengan timah (Sn) pada BaFe12-xInxO19 dengan x = 0,35 mampu menghasilkan penurunan koersivitas hingga 83% tetapi juga secara signifikan menurunkan remanen. Sementara itu, substitusi stronsium heksaferit dengan indium (In) pada SrFe12-xInxO19 untuk x = 0,1 mampu menurunkan koersivitas hingga 38% dengan hanya sedikit penurunan remanen. Pada penelitian ini, dipilih stronsium heksaferit dengan menggabungkan kedua variasi substitusi tersebut sehingga dihasilkan material SrFe11.55In0.1Sn0.35O19 (SHFInSn) melalui teknik powder metallurgy yang selanjutnya dikompositkan dengan material soft magnetic, FeCo, yang dihasilkan dari proses reduksi sehingga dihasilkan komposit dengan variasi perbandingan massa FeCo sebesar 10%, 30%, dan 50% yang memiliki koersivitas rendah tanpa penurunan remanen yang signifikan sehingga dapat diperoleh kemampuan absorpsi gelombang mikro yang lebih optimum. Hasil dari penelitian ini menunjukkan bahwa substitusi parsial stronsium heksaferit dengan indium (In) dan timah (Sn) terbukti menurunkan secara drastis koersivitas dan meningkatkan remanen serta saturasi dengan Hc = 105,6 kA/m; Mr = 0,2837 T; dan Ms = 0,442 T. Untuk komposit SHFInSn/FeCo, variasi dengan karakteristik terbaik dimiliki oleh kandungan 10% FeCo yang memiliki nilai koersivitas sebesar 92,82 kA/m, remanen sebesar 0,323 T, dan saturasi sebesar 0,561 T. Meski begitu, nilai reflection loss komposit semakin besar seiring dengan meningkatnya konsentrasi FeCo dengan nilai tertinggi sebesar -19,5 dB pada variasi 50% FeCo sehingga mampu menyerap hingga 89,4% gelombang mikro.

---

Permanent magnet materials like hexaferrite can have their properties modified to become radar absorbing materials by partially substituting their iron ions with other ions to lower their coercivity field (Hc) without a significant decrease in remanent magnetization (Mr). Commonly used hexaferrite materials are barium hexaferrite (BaFe12O19) and strontium hexaferrite (SrFe12O19) which have similar magnetic properties. Recent studies show that substituting barium hexaferrite with tin (Sn) on BaFe12-xInxO19 with x = 0.35 can produce a decrease in coercivity of up to 83% but also significantly lowers remanence. Meanwhile, substituting strontium hexaferrite with indium (In) on SrFe12-xInxO19 for x = 0.1 can lower coercivity by up to 38% with only a slight decrease in remanence. In this study, strontium hexaferrite was chosen by combining both substitution variations to produce SrFe11.55In0.1Sn0.35O19 (SHFInSn) material using powder metallurgy technique which was then composited with soft magnetic material, FeCo, that produced from the reduction process to produce composites with mass ratio variations of FeCo are 10%, 30%, and 50% which has low coercivity without significant decrease in remanence and also increases its saturation so that optimum microwave absorption capability can be obtained. The results of this study show that partial substitution of strontium hexaferrite with indium (In) and tin (Sn) has been proven to drastically reduce coercivity and increase remanence and saturation with Hc = 105,6 kA/m, Mr = 0,2837 T, and Ms = 0,442 T. For the SHFInSn/FeCo composite, the variation with the best characteristics is owned by 10% FeCo content which has a coercivity value of 92.82 kA/m, a remanence of 0.323 T, and a saturation of 0,561 T. However, the reflection loss value of the composite is greater as the FeCo concentration increases with the highest value of -19.5 dB at a variation of 50% FeCo so it can absorb up to 89.4% of microwaves."

"Sintesis dan karakterisasi material MoS2 telah dilakukan melalui metode hidrotermal menggunakan prekursor sodium molybdate dihydrate dan thiourea. Penelitian ini bertujuan untuk mendapatkan MoS2 dengan konsentrasi prekursor yang optimal diantara variasi prekursor 0,25 M; 0,5 M; 1,0 M; dan 1,5 M sehingga dapat menyerap gelombang mikro pada kisaran X-band secara efektif. Konsentrasi prekursor MoS2 divariasikan menjadi 0,25 M; 0,5 M; 1,0 M; dan 1,5 M disintesis dengan suhu reaksi 2000 C selama 24 jam. Karakterisasi MoS2 yang telah disintesis dilakukan dengan alat X-Ray Diffraction (XRD) untuk analisis fasa, Scanning Electron Microscopy – Energy Dispersive X-Ray Spectroscopy (SEM-EDS) untuk mengetahui morfologi yang terbentuk, Particle Size Analyzer (PSA) untuk mengetahui ukuran partikel, dan Vector Network Analyzer (VNA) untuk mengetahui kemampuan material dalam menyerap gelombang mikro. Dari hasil penelitian diperoleh MoS2 single phase dengan struktur heksagonal space group P63/mmc, memiliki morfologi nanosheet microsphere, memiliki ukuran partikel pada interval 138,3 hingga 189,6 nm, dan memiliki besar Reflection Loss sebesar -18,79 dB untuk konsentrasi 0,25 M; -19,6 dB untuk konsentrasi 0,5 M; -23,06 untuk konsentrasi 1,0 M; dan -24,23 untuk konsentrasi 1,5 M. Reflection Loss terbaik mencapai −24,23 dB pada frekuensi 10,34 GHz diperoleh saat konsentrasi prekursor MoS2 sebesar 1,5 M. Maka dapat disimpulkan bahwa konsentrasi prekursor MoS2 yang disintesis secara hidrotermal yang optimal diantara 0,25 M; 0,5 M; 1,0 M; dan 1,5 M adalah 1,5 M, dikarenakan kemampuannya menyerap gelombang mikro hingga 99,62% pada frekuensi 10,34 GHz.

---

Synthesis and characterization of MoS2 has been done through hydrothermal method with Sodium Molybdate Dihydrate and Thiourea as precursors. This research is done to obtain MoS2 with the optimal concentration among the precursor variations of 0.25 M; 0.5 M; 1.0 M; and 1.5 M to improve its ability to microwave absorption on the X-band. The 0.25 M, 0.5 M, 1.0 M and 1.5 M concentrations of the MoS2 is synthesized at temperature of 2000 C for 24 hours. The measurements that have been done to the sample are XRD for phase analysis, SEM-EDS for morphology identification, PSA to obtain particle size and VNA to identify the sample's microwave absorption abilities. Yielded results concluded that MoS2 single phase with a hexagonal structure and space group P63/mmc, has a nanosheet microsphere morphology, has a particle size in the interval of 138.8 to 189.6 nm, and has a Reflection Loss of -18.79 dB for concentration 0.25 M; -19.6 dB for a concentration of 0.5 M; -23.06 for a concentration of 1.0 M; and -24.23 for a concentration of 1.5 M. The best Reflection Loss reached -24.23 dB at a frequency of 10.34 GHz obtained when the precursor concentration of the MoS2 was 1.5 M. It can be concluded that the optimal precursor concentration of the hydrothermally synthesized MoS2 between 0.25 M; 0.5 M; 1.0 M; and 1.5 M is 1.5 M, due to its ability to absorb microwaves up to 99.62% at a frequency of 10.34 GHz."

"Material penyerap gelombang mikro telah banyak diteliti sebelumnya, terutama mengarah ke material paduan berbahan polimer. Dalam penelitian ini polimer konduktif yang digunakan adalah polianilin (PANi) yang dipadukan dengan paduan material barium heksaferit substitusi ion Ti dan Mn dan kobalt ferit (BHFTM/CFO), dimana material tersebut mempunyai sifat magnetik, karena pada dasarnya material yang bisa digunakan sebagai penyerap gelombang mikro adalah material yang mempunyai sifat dielektrik dan magnetik. Dengan kata lain suatu material dapat dikatan penyerap gelombang mikro jika memiliki sifat permitivitas, permeabilitas, total magnetisasi, dan resistivitas yang tinggi. PANi disintesa dengan menggunakan metoda polimerisasi oksidasi, sedangkan BHFTM dan CFO disintesa menggunakan metoda pemaduan mekanik dan dilakukan sonikasi untuk memperkecil ukuran partikel. Paduan PANi/BHFTM/CFO disintesa dengan cara menambahkan material pengisi ke dalam matriks PANi dengan rasio 20:80, 50:50, dan 80:20 (% berat) kemudian dilakukan pengepresan dengan tekanan sebesar 5 ton selama 10 detik sebanyak 2 kali. Karakterisasi nanokomposit diuji dengan menggunakan spektrofotometer FTIR untuk polimer, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Conductivity Meter (metoda four point probe), Particle Size Analyzer (PSA), Permagraph, dan Vector Network Analyzer (VNA). Dengan adanya substitusi ion pada material barium hexaferrit maka terdapat perubahan baik pada sifat magnetisasi dan penyerapan gelombang mikro. Karakterisasi XRD menunjukkan pola difraksi BHFTM tidak berbeda dengan BHF hanya terjadi pergeseran puncak. Sedangkan hasil karakterisasi SEM menunjukkan terjadi perpaduan antara BHFTM dan CFO. Hasil karakterisasi absorpsi dengan VNA menunjukkan adanya serapan pada komposit PHMM 2080 yaitu -20 dB pada frekuensi 12,8 GHz dimana komposit yang digunakan menggunkaan polianilin hasil doping (PANi-HCl) dan magnetik dalam multi kristalit partikel dengan rasio fraksi massa komponen polimer:magnetik sebesar 20:80. Perubahan ukuran partikel menjadi nano kristalit partikel menghasilkan serapan sebesar -19,08 db pada frekuensi 12,75 GHz (komposit PEMN 8020 atau komposit PANi-EB:Magnetik nano partikel dengan rasio fraksi massa 80:20).

---

Microwave absorber materials have been widely studied, especially leading to polymeric based composite materials. In this study, conductive polymers used are polyaniline (PANi) combined with a blend of material barium heksaferit substitution ion Ti and Mn and cobalt ferrite (BHFTM/CFO), wherein the material has magnetic properties, because basically materials that can be used as a microwave absorber if a material that has dielectric and magnetic properties. In other words the absorbent material can used absorbent if it has properties of permittivity, permeability, total magnetization and resistivity low. PANi synthesized by using the method polymerization oxidation while BHFTM and CFO were synthesized using a mechanical alloying synthesis method then sonication process for reduce particle size. PANi/BHFTM/CFO composite synthesized by adding a filler material into the matrix PANi with a ratio of 20:80, 50:50, and 80:20 (% by weight) and then do the pressing with a pressure of 5 tons for 10 seconds twice. The characterization of nanocomposite tested using FTIR spectrophotometer for the polymer, X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Conductivity Meter (method four-point probe), Particle Size Analyzer (PSA), Permagraph, and Vector Network Analyzer (VNA). With the substitution of ions in the barium hexaferrite material there is a change in both the magnetization and microwave absorption properties. XRD characterization shows BHFTM diffraction pattern is not different from BHF only peak shift occurs. While the results of SEM characterization shows a combination between BHFTM and CFO. The characterization results of absorption by VNA showed absorption at 2080 PHMM composite is -20 dB at 12.8 GHz frequency where composites are used menggunkaan polyaniline doping results (PANi-HCl) and magnetic particles in a multi crystallites with the ratio of the mass fraction of the polymer components: magnetic amounted 20:80. The change crystallite size particles into nano particles produce uptake of -19.08 db at a frequency of 12.75 GHz (8020 PEMN composites or composite PANi-EB:Magnetic nano-particles with mass fraction ratio of 80:20)."

"Material penyerap radar atau radar absorbing material (RAM) adalah suatu bahan yang mampu menyerap gelombang mikro yang dipancarkan oleh radar, untuk melindungi objek yang jauh dan tak terlihat.Kemampuan penyerapan gelombang mikro dari suatu material ditentukan dari adanya sifat resistif, dielektrik, dan/atau magnetik dari material. Pada penelitian ini telah dilakukan rekayasa material magnetik berbasis hexaferrite melalui subsitusi parsial ion Mn+2 dan Ti+4 terhadap ion Fe+3 pada senyawa dengan komposisi BaFe12-xMnx/2Tix/2O19 (x = 0; 0,1; 0,3; dan 0,5) disingkat BFMTO.Material magnetik berbasis heksaferit hasil rekayasa struktur tersebut dicampur dengan senyawa CoFe2O4 disingkat CFO membentuk material komposit dengan komposisi BFMTO:CFO divariasi 20:80; 50:50 dan 80:20 (% massa). Hasil evaluasi sifat kemagnetan dan karakteristik absorpsi gelombang mikro seluruh sampel menunjukkan bahwa nilai remanen sampel adalah terletak diantara nilai remanen BFMTO dan CFO tergantung kepada komposisi komposit. Efek subsitusi parsial pada barium hexaferrite menurunkan koersivitas magnet dan menentukan daya absorpsi material. Dapat disimpulkan bahwa komposisi material komposit 20:80 untuk semua nilai x memberikan nilai absorpsi tertinggi. Koersivitas sampel magnet komposit tidak jauh berbeda antar satu komposisi dengan komposisi yang lain, yaitu sekitar 80 kA/m. Sampel komposit antaraBFMTO (x= 0,3) dan CFO dengan komposisi 20:80 memiliki nilai reflection loss (RL) mencapai -21,31dB pada frekuensi 10,78 Ghz atau sebesar 91,4% intensitas gelombang mikro yang datang masuk kedalam material hanya dikembalikan sebesar 0,6 %.

---

Radar absorbing material (RAM) is a material capable of absorbing the microwaves emitted by radarto protect distance and invisible objects. The microwave absorption ability of a material is determined by the presence of the resistive, dielectric, and/or magnetic properties of such material. In the current research work, structural modification of hexaferrite-based materials has been carried out through partial substitution of Mn+2 and Ti+4 ions to Fe +3 ions in BaFe12-xMnx/2Tix/2O19 (x = 0; 0.1; 0.3; and 0.5), which abbreviated as BFMTO. Such material was mixed with the CoFe2O4 compound, which abbreviated as CFO to form a composite with the composition of BFMTO:CFO wa varied 20:80; 50:50 and 80:20 (wt.%). Result of evaluation of the magnetic properties and microwave absorption characteristics of all samples show that the remanent value of the sample lies between those of BFMTO and CFO ​​depending on the composition of the composite. The partial substitution effect of barium hexaferrite decreased the magnetic coercivity and determines the absorption power of the material. It can be concluded that the composition of the 20:80 composite for all x values ​​gives the highest absorption. The coercivity of the composite magnet samples is not much different from one composition to another, which is about 80 kA/m. The composite sample between BFMTO (x = 0.3) and CFO with a composition of 20:80 has a reflection loss (RL) value of -21.31dB at a frequency of 10.78 Ghz or 91.4% of the intensity of the microwaves entering the material, only 0.6% was returned."

"Nanokomposit Perak, Titanium dioksida, dan Mangan (II,III) oksida (Ag/TiO2/Mn3O4) dengan berbagai rasio molar telah disintesis menggunakan metode hidrotermal. Pengukuran difraksi sinar-X (XRD) mengkonfirmasi struktur nanokomposit Ag/TiO2/Mn3O4 yang terdiri dari struktur kubik Ag, TiO2 anatase, dan Mn3O4 tetragonal. Rasio komposisi unsur nanokomposit Ag/TiO2/Mn3O4 diselidiki dengan fluoresensi sinar-X (XRF). Efek sinergis Ag, TiO2 dan Mn3O4 dapat meningkatkan efisiensi nanokomposit sebagai fotokatalis. Peningkatan efisiensi ditunjukkan dengan melebarnya rentang absorbansi pada hasil pengukuran UV-Vis Diffuse Reflectance. Pengukuran adsorpsi-desorpsi nitrogen menunjukkan bahwa penambahan geraham TiO2 mengakibatkan penurunan luas permukaan spesifik nanokomposit Ag/TiO2/Mn3O4, sedangkan hasil sebaliknya diberikan dengan penambahan geraham Mn3O4. Pada uji fotokatalitik, hasil terbaik ditunjukkan oleh nanokomposit Ag/TiO2/Mn3O4 dengan dominasi Mn3O4 untuk radiasi UV dan cahaya tampak. Pada kondisi optimum, nanokomposit Ag/TiO2/Mn3O4 mampu mendegradasi metilen biru hingga 91% dengan penyinaran selama 2 jam. Uji scavenger mengidentifikasi lubang sebagai spesies yang berkontribusi paling besar pada proses fotokatalitik ini. Uji reusabilitas dan stabilitas pada nanokomposit Ag/TiO2/Mn3O4 menunjukkan hasil positif.

---

Silver, Titanium dioxide, and Manganese (II,III) oxide (Ag/TiO2/Mn3O4) nanocomposites with various molar ratios have been synthesized using the hydrothermal method. X-ray diffraction (XRD) measurements confirmed the structure of the Ag/TiO2/Mn3O4 nanocomposite consisting of a cubic structure of Ag, TiO2 anatase, and tetragonal Mn3O4. The elemental composition ratio of Ag/TiO2/Mn3O4 nanocomposite was investigated by X-ray fluorescence (XRF). The synergistic effect of Ag, TiO2 and Mn3O4 can increase the efficiency of nanocomposites as photocatalysts. The increase in efficiency is indicated by the widening of the absorbance range on the measurement results of UV-Vis Diffuse Reflectance. The nitrogen adsorption-desorption measurements showed that the addition of TiO2 molars resulted in a decrease in the specific surface area of ​​the Ag/TiO2/Mn3O4 nanocomposite, while the opposite result was given by the addition of Mn3O4 molars. In the photocatalytic test, the best results were shown by the Ag/TiO2/Mn3O4 nanocomposite with the dominance of Mn3O4 for UV radiation and visible light. Under optimum conditions, Ag/TiO2/Mn3O4 nanocomposite was able to degrade methylene blue up to 91% with irradiation for 2 hours. The scavenger test identified pits as the species that contributed most to this photocatalytic process. Reusability and stability tests on Ag/TiO2/Mn3O4 nanocomposites showed positive results."

"Tesis ini merupakan bahasan hasil penelitian fabrikasi material nanokomposit dengan perbaikan pada proses fabrikasi. Penelitian ini bertujuan untuk meningkatkan sifat mekanik dan termal dari material nanokomposit nanoclaypolipropilena melalui peningkatan panjang screw dalam mesin twin screw extruder (TSE). Screw pendek yang digunakan memiliki panjang 300 mm, sedangkan screw panjang ukurannya 600 mm. Formulasi dari nanokomposit adalah 3,5 % nanoclay dalam matrik polipropilena dengan aditif kompatibiliser 5 % PP-g-MA. Hasil pengamatan struktur mikro nanokomposit menggunakan scanning electron microscope (SEM) dan scanning probe microscope (SPM) menunjukkan bahwa hasil fabrikasi nanokomposit menggunakan mesin pencampur TSE screw panjang memiliki sebaran/dispersi nanoclay yang lebih baik dibanding hasil fabrikasi menggunakan screw pendek. Dari hasil pengujian sifat mekanik nanokomposit yang dilakukan yang meliputi kekuatan tarik, modulus kekakuan, kekerasan, ketahanan aus dan ketangguhan menunjukkan bahwa nanokomposit hasil fabrikasi menggunakan screw panjang sifat mekaniknyalebih baik. Modulus kekakuan meningkat 34 %, ketangguhan dan kekerasan meningkat 1 %,. Dampak positif dari penelitian ini adalah meningkatnya sifat termal nanokomposit hasil fabrikasi menggunakan screw panjang dari pada hasil fabrikasi menggunakan screw pendek, sifat termal yang dianalisis meliputi: temperatur dekomposisi, temperatur defleksi, kecepatan bakar dan temperature leleh. Bila dibandingkan dengan polipropilena, maka nanokomposit memiliki peningkatan sifat sdiantaranya termal defleksi 7 %, termal dekomposisi 2 % dan ketahanan bakar 8 %.

---

This thesis is a discussion of material manufacturing nanocomposites with improvements in the manufacturing process. This research aims is to improve the mechanical and thermal properties of nanoclay-polypropylene nanocomposites material through the longer screw in the twin screw extruder (TSE) mixer machine. Short screw used own length of 300 mm, while the other screw length of 600 mm in size. Formulation of nanocomposites is 3.5% nanoclay in polypropylene matrix with compatibilizer of 5 % PP-g-MA. The results of micro structure of nanocomposites observed by scanning electron microscope (SEM) and scanning probe microscope (SPM) showed that the nanocomposites manufacturing using a long screw found that the dispersion of nanoclay in nanocomposites is better than fabricated using a short screw. The mechanical testing of nanocomposites materials includes a tensile strength, elastic modulus, hardness, impact, and wear resistance the results showed that the nanocomposites manufacturing use longer screw have increased of mechanical properties, elastic modulus improve 34 %, impact charpy and hardness improve 1 %,. The side effect of this research is thermal properties of nanocomposites manufacturing use long screw was increased compared nanocomposites manufacturing using short screw. The thermal properties has analysed by flammability, thermal decomposition, thermal deflection, and melting temperature. Compare to polypropylene, the nanokomposites as manufacture has improve thermal deflection 7 %, thermal decomposition 2 % and flame retardant 8 %."

"Pencemaran lingkungan adalah salah satu masalah serius disebabkan pembuangan limbah berbahaya dan beracun dari industri–industri yang tidak teregulasi. Salah satu material yang banyak digunakan sebagai zat warna adalah sunset yellow pada industri tekstil yang berdampak buruk, menyebabkan risiko kesehatan seperti depresi, kerusakan ginjal, kerusakan hati, dan kanker. Pada penelitian ini telah dilakukan sintesis nanokomposit Nanochitosan/Fe₃O₄−SrSnO₃ untuk mendegradasi zat warna sunset yellow. Nankomposit Nanochitosan/Fe₃O₄−SrSnO₃ dikarakterisasi dengan Fourier–transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–Vis), X–ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high–resolution transmission electron microscopy (HRTEM), Brunauer–Emmet–Teller (BET) dan ultraviolet visible–diffuse reflectance (UV–DRS). Pengaruh Fe₃O₄ terhadap sisi aktif SrSnO₃ telah dipelajari dan energi celah pita dari SrSnO₃ menjadi 2,4 eV dengan komposisi Fe₃O₄/SrSnO₃ (3:1) dengan persen degradasi sebesar 88,45% . Nanochitosan ditambahkan sebagai support meningkatkan aktivitas dari nanokomposit Fe₃O₄−SrSnO₃ dengan persen dgradasi 97,42%. Nanokomposit yang optimal yang digunakan untuk analisis kinetika reaksi dan isoterm adsorpsi adalah dengan kondisi massa 0,04 gram, pH 10, dan waktu selama 75 menit. Kinetika reaksi mengikuti psuedo first order dengan konstanta laju reaksi 0,058 dan sesuai dengan isoterm adsorpsi Langmuir

---

Environmental pollution is one of the most serious problems caused by the disposal of hazardous and toxic waste from unregulated industries. One material that is widely used as a dye is sunset yellow in the textile industry which has adverse effects, causing health risks such as depression, kidney damage, liver damage, and cancer. In this study, Nanochitosan/ Fe₃O₄−SrSnO₃ nanocomposite has been synthesized to degrade sunset yellow dye. Nanochitosan/ Fe₃O₄−SrSnO₃ nanocomposites were characterized by Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmet-Teller (BET) and ultraviolet visible-diffuse reflectance (UV-DRS). The effect of Fe3O4 on the active side of SrSnO₃ was studied and the band gap energy of SrSnO₃ became 2.4 eV with Fe₃O₄/SrSnO₃ composition (3:1) with a percent degradation of 88.45%. Nanochitosan added as support increases the activity of Fe₃O₄−SrSnO₃ nanocomposite with 97.42% degradation percent. The optimal nanocomposite used for the analysis of reaction kinetics and adsorption isotherms was with a mass condition of 0.04 grams, pH 10, and time for 75 minutes. The reaction kinetics followed first order psuedo with a reaction rate constant of 0.058 and fit the Langmuir adsorption isotherm."

"Epoxy-organo clay nanocomposite materials are constructed from a polymer as a matrix and an organoclay as filler. Epoxy-organo clay nanocomposites have been synthesized using various curing agents. The aim of this research was to study the influence of the curing agent and the organoclay contents to the structure and mechanical properties of nanocomposites materials. Epoxy-organo clay nanocomposites were synthesized using cycloaliphatic amine as a curing agent and a montmorillonite organoclay (MMT) as filler through an in situ polymerization method. XRD and TEM technique provide more detail information to understand the structure that relates to the mechanical properties of the materials. Tensile test, compressive test and hardness test were conducted based on ASTM and JIS standards. The fracture surfaces after tensile tests were analyzed using SEM. The nanocomposite properties were compared to glass-fiber composites which were synthesized using wet-laminating method.It was found that the curing agent is influence to the nanocomposites structure which was shown by the change of d-spacing before and after the addition of the agent curing. XRD and TEM techniques showed that both intercalated and exfoliated structure have been formed. TEM image also exhibited that the number of intercalated structure was higher when the organoclay content was higher. It can be said that TEM techniques provides a better understanding of the nanocomposites structure and the number intercalated structure increase as the organoclay increases.The organoclay contain also influences to mechanical properties of nanocomposite materials. The addition of 10.5 wt.% organoclay improved the tensile modulus by 185% but and decreased tensile strength by 186% and 49%, and these values are lower of 36% and 90% compared to glass fiber composites. These decreases in the strength may be attributed to the fact that agglomerate and void was formed. From compression test, the addition of 3.1 wt.% organoclay demonstrated a 102% increase in compression strength and a 93% increase in load maximum compare to epoxy resin. But, that compression strength value lower of 11% compared to glass fiber composites. For the maximum load, the addition of 3.1 wt.% organoclay improved 246% compared to glass fiber composites. Addition of 7.3 wt.% organoclay demonstrated an increase of modulus of the epoxy resin by 93% and 2% compare to glass fiber composites. Meanwhile, the addition of 10.5% organoclay cause decreasing in yield compression up to 31%, but this higher value equal to 406% from is glass fiber composites. While that, result of hardness test do not show the make-up of value meaning in comparison with epoxy matrix."