scholarly journals Sintesis dan Karakterisasi CNT (Carbon Nanotube) Berdopan Logam Kobalt

2014 ◽  
Vol 17 (3) ◽  
pp. 80-85
Author(s):  
Nur Dwi Lestari ◽  
Pardoyo Pardoyo ◽  
Agus Subagio

Telah dilakukan penelitian sintesis dan karakterisasi CNT (Carbon Nanotube) dengan doping logam kobalt. Penelitian ini bertujuan untuk menentukan karakter CNT sebelum dan setelah didoping dengan variasi konsentrasi logam 10%, 20%, 30%, 40% dan 50%. Metode yang digunakan pada penelitian ini adalah impregnasi basah yang meliputi perendaman pada larutan logam dan kalsinasi. Hasil impregnasi dianalisis menggunakan Fourier Transform-Infra Red (FT-IR), GSA (Gas Sorption Analysis), Scanning Electron Microscopy (SEM) dan Energy Dispersive X-Ray Spectroscopy (EDS). Analisis FT-IR menunjukkan adanya vibrasi ulur dari ikatan Co-C dan Co-O.  Hasil GSA menunjukkan bahwa CNT loading 30% mempunyai luas permukaan tertinggi yaitu 69,192 m2/g. Hasil SEM-EDS menunjukkan bahwa morfologi permukaan dinding CNT ditutupi aggregat-aggregat kobalt. Pada hasil EDS fraksi kobalt dihasilkan adalah 1,96 % yang nilainya tidak jauh berbeda dari fraksi Fe yaitu 1,49%. Hal ini menunjukkan bahwa CNT doping logam Co menggunakan metode impregnasi basah tidak efektif.

2019 ◽  
Vol 6 (2) ◽  
pp. 85
Author(s):  
Nuryanti Nuryanti ◽  
Rahayu Wijayanti ◽  
Masdikoh Masdikoh

Isopulegol penting sebagai senyawa intermediate dalam pembuatan menthol (C10H20O) yang mempunyai karakteristik bau peppermint dan digunakan secara luas dalam industri farmasi, industri sabun dan pasta gigi. Isopulegol sangat mahal karena banyak digunakan di dunia green medicine. Penelitian ini bertujuan untuk menghasilkan Isopulegol dengan reaksi cyclisasi citronellal menggunakan katalis heterogen ZnBr2/SiO2. Awalnya dilakukan pembuatan katalis heterogen ZnBr2/SiO2 selanjutnya dilakukan pemisahan fraksi citronellal dari citronella oil dengan destilasi fraksinasi vacuum. Fraksi citronellal yang digunakan diperoleh dari hasil isolasi citronella oil pada tekanan 33 mBarr. Dilakukan reaksi cyclisasi citronellal untuk menghasilkan isopulegol. Beberapa teknik seperti Fourier Transform Infra Red (FTIR) dan Scanning Electron Microscopy Energy Dispersive X-Ray Analysis (SEM-EDX) digunakan untuk karakterisasi katalis. Gas Chromatoghraphy Mass Spectroscopy (GC-MS) digunakan untuk analisis produksi isopulegol. Reaksi yang dilakukan menunjukkan bahwa katalis sangat selektif terhadap produk yang dihasilkan yaitu isopulegol dengan aktifitas katalis sebesar 95.63 % dan selektifitas terhadap isopulegol sebesar 94.35 %. Regenerasi katalis juga menunjukkan hasil yang baik terhadap produk yang dihasilkan dengan aktifitas sebesar 94.38 %.


2019 ◽  
Vol 29 (2) ◽  
Author(s):  
Mutia Dewi Yuniati ◽  
Feronika Cinthya Mawarni Putri Wawuru ◽  
Anggoro Tri Mursito ◽  
Iwan Setiawan ◽  
Lediyantje Lintjewas

Magnesite (MgCO3) is the main source for production of magnesium and its compound. In Indonesia, magnesite is quite rare and can be only found in limited amount in Padamarang Island, Southeast Sulawesi Provence. Thus the properties of magnesite and the reactivity degree of the obtained product are of technological importance. The aim of this work was to analyze the characteristics of Padamarang magnesite under calcination and hydrothermal treatment processes. The processes were carried out at various temperatures with range of 150-900°C for 30 minutes. The solids were characterized with respect to their chemical and physical properties by using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). SEM image indicates that magnesite was formed from thin and flat hexagon sheets. The FTIR and XRD analysis disclose that MgO formed at temperature above 300°C, where as the magnesite sample also lost its mass around 50%. These results demonstrate that Padamarang magnesite decomposes to magnesium oxide and carbon dioxide at high temperature.Magnesit (MgCO3) merupakan sumber utama untuk produksi magnesium dan senyawa-senyawanya. Di Indonesia, magnesit cukup jarang dan hanya dapat ditemukan dalam jumlah yang terbatas di Pulau Padamarang, Propinsi Sulawesi Tenggara. Oleh karena itu sifat magnesit dan derajat reaktivitas dari produk-produk magnesit penting untuk diketahui. Penelitian ini bertujuan untuk menganalisis karakteristik magnesit Padamarang dengan perlakuan kalsinasi dan hidrothermal.  Proses dilakukan pada temperatur yang bervariasi dari 150-900°C selama 30 menit. Sifat kimia dan fisika dari magnesit dikarakterisasi dengan menggunakan scanning electron microscopy dengan energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FTIR), dan X-ray diffraction (XRD). Gambar dari analisis SEM menunjukkan bahwa magnesit terbentuk dari lembaran-lembaran heksagonal yang tipis dan datar. Hasil analisis dengan FTIR dan XRD menunjukkan bahwa MgO terbentuk pada temperatur diatas 300°C, dimana sampel magnesit juga kehilangan massanya sekitar 50% pada suhu tersebut. Hal ini menunjukkan bahwa Magnesit Padamarang terdekomposisi menjadi magnesium oksida dan karbon dioksida pada temperatur tinggi.


RSC Advances ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 3060-3071
Author(s):  
Angela F. Danil de Namor ◽  
Salman Alharthi ◽  
Brendan Howlin ◽  
Nawal Al Hakawati

A recyclable mercury(ii) selective dimer based on a calix[4]pyrrole derivative has been synthesised and characterised by mass and FT-IR spectrometry, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX).


2013 ◽  
Vol 774-776 ◽  
pp. 629-633
Author(s):  
Ji Feng Jiang ◽  
Kang Kang Guo ◽  
Ya Ping Zhu ◽  
Fan Wang ◽  
Hui Min Qi

Triethynylborazine-polyhydromethylsiloxane copolymers (TEB-PHMSs) were prepared through hydrosilylation reaction between -C≡CH attached to boron and ≡Si-H. The structures of TEB-PHMSs were characterized by Fourier transform Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR) spectroscopy. Their cure behavior were examined by Differential Scanning Calorimeter (DSC) and FT-IR, and then thermostability and ceramization of cured TEB-PHMS were investigated by Thermogravimetric analysis (TGA), pyrolysis-GC-MS, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The results indicated that TEB-PHMSs could be cured and converted into an outstanding thermostable SiBCN ceramics.


2019 ◽  
Vol 9 (6) ◽  
pp. 4685-4698

Three wooden Coptic icons located at Saint Mercurius Monastery in Tamooh, Giza, Egypt were comprehensively investigated in order to determine the possible causes of their deterioration. Samples from every paint used in each icon were collected spanning from the outermost varnish layer down to the ground layer. Investigation was carried out using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF). For interaction between the icon layers DFT calculations at B3LYP/6-31g(d,p) level were conducted in order to study the effect of humidity on the reactivity of the binder material and its possible role in the deterioration of the icons.


2020 ◽  
Vol 16 (5) ◽  
pp. 770-778
Author(s):  
Mustafa Aghazadeh ◽  
Mohammad Reza Ganjali ◽  
Mina Mohebi Morad ◽  
Davoud Gharailou

Background: Recently, superparamagnetic and electromagnetic nano-materials have been extensively studied and their potential applications have also been investigated in various fields. In this regard, currently, Fe3O4 NPs are valuable candidates as diagnostic agents such as magnetic resonance imaging, enzyme immobilization, biosensing and cell labeling, and therapeutic probes, including drug delivery, bacteria detection, magnetic separation, and hyperthermia agents. Objective: In this study, electrochemical synthesis of Cu2+ cations-doped superparamagnetic magnetite nanoparticles (Cu-SMNPs) and their in situ surface coating with saccharides (i.e., glucose, sucrose and starch) are reported. The prepared glucose/Cu-SMNPs, sucrose/Cu-SMNPs and starch/Cu-SMNPs samples are characterized by structural, magnetic and morphological analyses by XRD, FT-IR, FE-SEM, EDAX and VSM. The suitability of the prepared samples for biomedical use is also proved. Methods: A simple cathodic electrochemical set-up was used to fabricate the iron oxide samples. The bath electrolyte was one litre deionized water containing 1.5g iron chloride, 3g iron nitrate, 0.5g copper chloride and 0.5g saccharide (i.e., glucose or sucrose or starch). The cathode and anode electrodes were connected to a DC power supply (PROVA 8000) as the power source. The deposition experiments were conducted at 10 mA cm-2 for 30 min. For the preparation of glucose/Cu-SMNPs, sucrose/Cu-SMNPs and starch/Cu-SMNPs samples, three electrodeposition experiments were carried out in three similar baths with only a change in the dissolved saccharide type. The prepared SMNPs samples were characterized by structural, morphological and magnetic analyses including X-ray powder diffraction (XRD, a Phillips PW-1800 diffractometer Smart Lab), field-emission scanning electron microscopy (FE-SEM, Mira 3-XMU with accelerating voltage of 100 kV), transmission electron microscopy (TEM, model Zeiss EM900 with an accelerating voltage of 80 kV), fourier transform infrared (FT-IR, a Bruker Vector 22 Fourier transformed infrared spectrometer) and vibrating sample magnetometers (VSM, model Lakeshore 7410). Results: Three types of metal-cations doped superparamagnetic magnetite nanoparticles (SMNPs), glucosegrafted Cu2+-doped MNPs (glucose/Cu-SMNPs), sucrose-grafted Cu2+-doped SMNPs (sucrose/Cu-SMNPs) and starch-grafted Cu2+-doped SMNPs (starch/Cu-SMNPs), were prepared for the first time. Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy and energy dispersive X-ray techniques proved the presence of saccharide capped layer on the surface of deposited SMNPs and also copper cations doping on their crystal structures. Superparamagnetic behaviors, including low coercivity and remanence values, were observed for all the prepared samples. Conclusion: SMNPs capped with saccharides (i.e., glucose, sucrose and starch) were successfully synthesized via one-pot simple deposition procedures. These particles showed suitable superparamagnetic properties with negligible remanence values and proper saturation magnetization, thus proving that they all have required physicochemical and magnetic characteristics for biomedical purposes.


2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Veni Dayu Putri

<p><strong>ABSTRAK</strong></p><p><strong> </strong></p><p>Pembuatan lapisan tipis kalsium fosfat dari kalsium nitrat tetrahidrad (Ca(NO<sub>3</sub>)<sub>2</sub>.4H<sub>2</sub>O) sebagai prekursor kalsium dan asam fosfat (H<sub>3</sub>PO<sub>4</sub>) sebagai <em>prekursor</em> fosfat dengan variasi perbandingan mol Ca/P 1.50 , 1.60 , 1.67 , 1.70 dan 1.80 melalui metode sol-gel telah dilakukan. Sol yang didapat dibakar pada suhu 1000<sup>o</sup>C sehingga terbentuk powder kalsium fosfat berwarna putih. Powder yang didapat dianalisis menggunakan Fourier Transform Infra Red Spectroscopy (FTIR), X-Ray Diffraction (XRD) dan Scanning Electron Microscopy (SEM). Analisis FTIR menunjukkan adanya serapan gugus PO<sub>4</sub><sup>3-</sup>, O-H, H<sub>2</sub>O, CO<sub>2</sub>, dan P<sub>2</sub>O<sub>7</sub><sup>4-</sup>. Difraksi sinar-X dari powder yang terbentuk memberikan puncak pada sudut 2θ yang berbeda yaitu <em>Calsium Pyrophospate</em> (Ca<sub>2</sub>P<sub>2</sub>O<sub>7</sub>) dan <em>Hydroxyapatite</em> HAP (Ca<sub>10</sub>(PO<sub>4</sub>)<sub>6</sub>(OH)<sub>2 </sub>pada perbandingan molar Ca/P 1.80 . Analisis SEM menghasilkan <em>Hydroxyapatite </em>dan <em>Calsium Pyrophospate </em>dengan distribusi partikel yang tidak merata dan berbentuk <em>spheric</em>. Proses pelapisan dilakukan pada plat kaca yaitu pada perbandingan mol Ca/P 1.80 menggunakan metode dip-coating dan kemudian dipanaskan pada suhu 400<sup>o</sup>C. Hasil analisa XRD pada lapisan kalsium fosfat memperlihatkan bahwa senyawa yang terbentuk berbentuk amorf. Sedangkan analisis menggunakan SEM memperlihatkan bahwa lapisan tipis kalsium fosfat memiliki morfologi permukaan yang halus, rapat, homogen dan berbentuk <em>speric</em>.</p><p> </p><p>         <strong><em>Kata kunci</em></strong> : kalsium fosfat, <em>hydroxyapatite</em>, <em>dip-coating</em>, metode sol-gel</p><p> </p><p><strong>ABSTRACT</strong></p><p align="center"><strong> </strong></p><p><em>Preparation a thin layer of calcium phosphate using tetrahidrad calcium nitrate (Ca(NO<sub>3</sub>)<sub>2</sub>.4H<sub>2</sub>O) as a precursor of calcium and phosphoric acid (H<sub>3</sub>PO<sub>4</sub>) as a precursor of phosphate with a variation of the mole ratio Ca/P 1.50; 1.60, 1.67, 1.70 and 1.80 through the sol-gel method have been done. Sol obtained burned at a temperature of 1000<sup>o</sup>C to form white powder of calcium phosphate. Powder obtained were analyzed using Fourier Transform Infra Red Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). FTIR analysis showed absorption PO<sub>4</sub><sup>3-</sup> group,  O-H, H<sub>2</sub>O, CO<sub>2</sub>, and P<sub>2</sub>O<sub>7</sub><sup>4-</sup>. X-ray diffraction from powder formed providing a peak at an angle 2θ different namely Calcium Pyrophospate (Ca<sub>2</sub>P<sub>2</sub>O<sub>7</sub>) and Hydroxyapatite HAP (Ca<sub>10</sub>(PO<sub>4</sub>)<sub>6</sub>(OH)<sub>2</sub>) at a molar ratio of Ca/P 1.80. Analysis of SEM produces Hydroxyapatite and Calcium Pyrophospate with particle distribution is uneven and shaped spheric. The coating process performed on glass plates with mole ratio of Ca/P 1.80 using a dip-coating and then heated at a temperature of 400<sup>o</sup>C. XRD analysis on a layer of calcium phosphate showed that the compound formed shaped amorphous. While using SEM analysis showed the morphology of thin layer of calcium phosphate are smooth, dense, homogeneous and shaped speric.</em></p><p><em> </em></p><p><em>         <strong>Keywords :</strong> calcium phosphate, hydroxyapatite, dip-coating, sol-gel method</em></p>


RSC Advances ◽  
2016 ◽  
Vol 6 (54) ◽  
pp. 48329-48335 ◽  
Author(s):  
Heng-Zhi Duan ◽  
Hong-Yan Zeng ◽  
Hua-Miao Xiao ◽  
Chao-Rong Chen ◽  
Gao-Fei Xiao ◽  
...  

SO42− intercalated Mg–Al hydrotalcite (S-LDH) was prepared under microwave irradiation and characterized by powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM).


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