Adsorption characteristics of graphene oxide nanosheets on cement

RSC Advances ◽  
2016 ◽  
Vol 6 (68) ◽  
pp. 63365-63372 ◽  
Author(s):  
Min Wang ◽  
Rumin Wang ◽  
Hao Yao ◽  
Zhujun Wang ◽  
Shuirong Zheng

The adsorption characteristics of graphene oxide nanosheets on cement were investigated using scanning electron microscopy (SEM), total organic carbon (TOC), Fourier transform infrared spectra (FTIR) and XPS analyses.

2011 ◽  
Vol 368-373 ◽  
pp. 280-284
Author(s):  
Li Bin Bai ◽  
Xin Ying Qin ◽  
Hai Song Zhang ◽  
Hong Chi Zhao ◽  
Xin Wu Ba

In this article, graft copolymerization of styrene (St) onto cassava starch via potassium diperiodatonickelate (IV)–starch redox system as an initiator was investigated in an alkaline medium. The effects of reaction variables were investigated, and the grafting conditions were optimized. The equation of the polymerization rate were obtained, Rp= k•C1.02 (St)•C0.53 (Ni(IV)). The graft copolymer was characterized with Fourier-transform infrared spectra analysis (FTIR) and scanning electron microscopy (SEM). FTIR spectra indicated the presence of PSt-g-starch copolymer. SEM micrographs also showed PSt adhering on the starch.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.


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.


2020 ◽  
Vol 15 (11) ◽  
pp. 1406-1411
Author(s):  
Yi-Fan Cheng ◽  
Ling-Na Xu ◽  
Tian-En Chen ◽  
Guo-Zhen Jiang ◽  
Jia-Bin Wang

Crosslinked polyethylene (XLPE) cable has been widely used and studied with its specific failure mechanism. Among them, although thermal aging of XLPE insulation materials has been widely studied, the effect of accelerated thermal aging on the sulfur corrosion of XLPE cable has not been studied much. For further understand the mechanism of sulfur corrosion, the accelerated thermal aging method was taken with 200 mg/kg DBDS based on the distinguish of temperature. The macro and micro analysis contrast test before and after corrosion were also taken to investigate the morphology difference, the element distribution, the influence of thermal aging and DBDS addition the corrosion of copper core, and the assessment of insulation layer was also carried out by Fourier transform infrared spectra and spectroscopy, scanning electron microscopy to distinguish the microstructure and composition. Under the accelerated thermal aging experiment with DBDS, both copper core and insulation layer of sample No. 1 exhibit the most serious corrosion and aging condition. On the surface of the copper core, the DBDS-Cu complexes decompose to produce Cu2S and the temperature has a direct effect on this reaction. The insulation layer of sample No. 1 showed the most severe aging situation, with characteristic peaks of carbonyl appearing at 1720 cm-1 in the Fourier transform infrared tests and more defects, holes and cracks found in spectroscopy, scanning electron microscopy images.


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