Comparative Study of Chemical and Mechanical Treatment Effects on Bacterial Cellulose from Nata de Coco

2017 ◽  
Vol 888 ◽  
pp. 256-261
Author(s):  
Rusaini Athirah Ahmad Rusdi ◽  
Zul Hazrin Zainal Abidin ◽  
Hairul Anuar Tajuddin ◽  
Fauziah Abdul Aziz ◽  
Norhana Abdul Halim

In this work, bacterial cellulose was obtained from nata de coco. Initially, the samples were subjected to three types of different condition which were raw, chemical treatment and mechanical treatment. Bacterial cellulose was characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffractometer (XRD) and Field Emission Scanning Electron Microscopy (FESEM). Bacterial cellulose met the specifications of pure cellulose either using chemical or mechanical treatments proved by IR spectra reading. XRD results indicated that the crystallinity of chemical treatment bacterial cellulose is higher than the mechanical treatment bacterial cellulose which was 68.6% and 59.5% respectively. The FESEM analysis shows that the size of the bacterial cellulose that obtained from chemical treatment is smaller than mechanical treatments which were 19.42μm and 50.35μm.

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.


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.


2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Shuai Zhang ◽  
Jin Luo

LiOH/urea/thiourea aqueous systems have been successfully applied to the dissolution of bacterial cellulose (BC) and alginate (AL) to prepare blend fibers. Morphology, compatibility and mechanical properties of the blend fibers were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and tensile tests. The analyses indicated a good miscibility between alginate and bacterial cellulose, because of the strong interaction from the intermolecular hydrogen bonds. The mechanical properties of BC/AL blend fibers were significantly improved by introducing bacterial cellulose.


2014 ◽  
Vol 556-562 ◽  
pp. 109-112
Author(s):  
Shu Min Zheng ◽  
Kai Ming Wang

Lizardite were synthesized by hydrothermal reaction in an Fe3+doped solution/environment using nanometer SiO2and MgO as precursors. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR). The results show that: the synthetic samples are lizardite with a thickness ranging from 60 nm to 200 nm in the temperature range 200°C~230°C.


2015 ◽  
Vol 1119 ◽  
pp. 466-470 ◽  
Author(s):  
Radek Ševčík ◽  
Petra Mácová ◽  
Marta Pérez-Estébanez

CaCO3 polymorphs are intensively studied due to their importance in the nature and the widespread use in the industry as well. This work is dealing with the crystallization of aragonite from vaterite dispersion during the refluxation at 100°C. The characterization of CaCO3 polymorphs during vaterite transformation was performed with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray powder diffraction (XRPD). The influence of the different refluxing times on the aragonite crystallization was discussed. The purest aragonite, 70.7(2) wt.%, was synthetized in the sample refluxed for 60 minutes. Prolonged refluxation strongly affected aragonite crystals with gradual transformation into calcite.


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