scholarly journals Pengaruh Konsentrasi Asam Terhadap Sifat Fisik dan Muatan Permukaan Selulosa Termodifikasi

2019 ◽  
Vol 15 (2) ◽  
pp. 315
Author(s):  
Agus Wedi Pratama ◽  
Bambang Piluharto ◽  
Dwi Indarti ◽  
Tanti Haryati ◽  
Hardian Susilo Addy

<p>Selulosa merupakan salah satu biopolimer melimpah yang banyak digunakan dalam berbagai bidang seperti kertas, energi dan material komposit. Hidrofilisitas, dapat diperbaharui, ramah lingkungan dan aman adalah sifat-sifat selulosa yang dapat berpotensi menjadi material maju. Berdasarkan sifat-sifatnya, selulosa dapat dimodifikasi untuk menghasilkan sifat fungsional yang sesuai dengan aplikasinya. Dalam penelitian ini, selulosa mikrokristalin (MCC) dimodifikasi melalui metode hidrolisis asam. Prinsip metode ini adalah penghilangan bagian <em>amorf</em> pada selulosa oleh asam, meninggalkan bagian kristal. Selain itu, ketika asam digunakan sebagai agen hidrolisis, maka akan menghasilkan muatan permukaan pada selulosa. Dalam penelitian ini, pengaruh berbagai konsentrasi asam pada struktur kimia, kristalinitas, morfologi dan muatan permukaan telah dikaji. Perubahan struktur selulosa dianalisis menggunakan <em>Fourier Transform Infra Red </em>(FTIR), kristalinitas menggunakan <em>X-ray Diffraction</em> (XRD), morfologi menggunakan <em>Scanning Electron Microscopy</em> (SEM) dan muatan permukaan menggunakan titrasi konduktomteri. Hasil analisis FTIR menunjukkan masuknya gugus sulfat pada struktur selulosa. Analisis XRD menunjukkan peningkatan kristallinitas dalam selulosa termodifikasi seiring bertambahnya konsentrasi asam. Hasil analisis morfologi menunjukkan partikel dalam selulosa termodifikasi (CM) lebih tersebar daripada MCC. Analisis titrasi konduktometri menunjukkan bahwa mengalami peningkatan muatan permukaan pada CM seiring dengan bertambahnya konsentrasi asam. Oleh karena itu, dapat disimpulkan bahwa pengaruh konsentrasi asam sulfat pada hidrolisis selulosa memberikan dampak yang signifikan pada sifat fisik dan muatan permukaan.</p><p><strong>Effect of Acid Concentration on Physical Properties and Surface charge of Modified Cellulose</strong>. Cellulose is one of abundant biopolymer that many widely used in various applications such as paper, energy and composite material. Hydrophilicity, renewable, biodegradable, and safety are cellulose properties that can became potential of advance materials. In the utilization, cellulose can be modified its properties for different purposes. In this work, microcrystalline cellulose (MCC) was modified by acid hydrolysis method. The principle of this method is removed amorphous region of cellulose by acid and leaving crystalline phase. Moreover, when acid was used as hydrolyzing agent, it produce the surface charge on cellulose. In this research, the effect of various concentration of acid on the chemical structure, crystallinity, morphology and surface charge have studied. The chemical structures were analyzed using Fourier Transform Infra Red (FTIR), crystallinity using X-ray Diffraction (XRD), morphology using Scanning Electron Microscopy (SEM), and surface charge using titration conductometric. The FTIR analysis result has successfully showed the entry of sulfate groups on the cellulose structure. The XRD analysis showed increasing crystallinity in Cellulose Modified (CM) with increase acid concentration. By morphology analysis, particles in CM more disperse than MCC. Analysis of conductometric titration shows that there is an increase in surface charge in CM as acid concentration increases. Thus, the effect of sulfuric acid concentration on hydrolysis of cellulose has a significant impact on physical properties and surface charge.</p>

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>


2020 ◽  
Vol 16 (2) ◽  
pp. 171
Author(s):  
Wahyuni Wahyuni ◽  
Subaer Subaer ◽  
Nurhayati Nurhayati

Telah dilakukan penelitian tentang geopolimer berbasis fly ash dengan penambahan abu sekam padi. Penelitian ini bertujuan untuk mengetahui struktur dan sifat mekanik geopolimer berbasis fly ash dengan penambahan abu sekam padi. Geopolimer berbasis fly ash dibuat dengan penambahan abu sekam padi 0%, 20% dan 40% menggunakan metode aktivasi alkali dan dipanaskan pada suhu 70℃ selama 2 jam. Struktur mikro dari sampel  diketahui dengan menggunakan teknik X-Ray Diffraction (XRD) dan menggunakan Scanning Electron Microscopy (SEM). Gugus fungsi dari sampel diperoleh berdasarkan pengujian Fourier Transform Infra Red (FTIR). Sifat mekanik seperti Kuat tekan dari sampel diuji menggunakan Testing Mechine. Massa jenis, porositas dan kuat lentur dilakukan pengukuran terhadap sampel. Hasil penelitian menunjukkan diperoleh fase trydimate yang tertinggi pada sampel Geo FA+ASP (60+40)%. Hasil karakterisasi Scanning Elektron Microscopy (SEM) menunjukkan material penyusun sampel telah berikatan dengan baik walaupun sebagian kecil pertikel fly ash dan abu sekam padi masih terlihat dengan jelas. Gugus fungsi pembentuk geopolimer diperoleh pada stretching Si-O-Si dengan nilai gelombang antara 478-461cm-1 dan 791-781cm-1. Massa jenis tertinggi diperoleh pada sampel dengan penambahan 40% abu sekam padi dan porositas tertinggi diperoleh pada sampel tanpa penambahan abu sekam padi. Kuat tekan yang terbesar diperoleh dari sampel geopolimer berbasis fly ash tanpa penambahan abu sekam padi sedangkan kuat lentur tertingi diperoleh dari sampel geopolimer berbasis fly ash dengan  penambahan abu sekam padi sebesar 40%.


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 35 (4-5) ◽  
pp. 389-398
Author(s):  
Tarık Eren ◽  
Gülay Baysal ◽  
Faik Doğan

There is a growing interest in new type of biocidal compounds with antibacterial properties against bacteria. In this study, new antibacterial synthetic materials bearing curcumin and cationic polymers were synthesized. In the synthesis stage, the methacrylate functional cationic monomer was synthesized via the Michael addition route by using 3-acryloxy-2-hydroxypropyl methacrylate and 3-amino pyridine to obtain Monomer 1. Monomer 1 was further quaternized with hexyl bromide to obtain a cationic methacrylate functional monomer. Free-radical polymerization of Monomer 1 and methyl acrylate was conducted in the presence of azobisisobutyronitrile under dimethylformamide solvent. The composite formulation was conducted by using turmeric extract Curcuma longa (curcumin), hydroxyapatite, montmorillonite, and silver nitrate. The materials were analyzed by using the methods of X-ray diffraction, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and scanning electron microscopy. The biocidal activities against the bacteria Escherichia coli, Listeria monocytogenes, Salmonella, and Staphylococcus aureus were analyzed using agar well diffusion method. From the Fourier transform infrared, X-ray diffraction, and scanning electron microscopy analysis results of the synthesized nanocomposites, it is seen that they form strong connections with the components added to the composites and form an exfoliated structure. According to the antibacterial analysis results, the nanocomposites obtained have showed a strong antibacterial resistance against E.coli, L.monocytogenes, Salmonella, and S. aureus bacteria, and the high inhibition zone areas were obtained.


2016 ◽  
Vol 19 (1) ◽  
pp. 001-005 ◽  
Author(s):  
Paul Nesamony Prathiba Jeya Helan ◽  
Kannusamy Mohanraj ◽  
Sethuramachandran Thanikaikarasan ◽  
Thaiyan Mahalingam ◽  
Ganesan Sivakumar ◽  
...  

Copper tin sulphide nanoparticles have been prepared by solution growth technique at various ethylenediamine concentrations. Prepared samples have been characterized using x-ray diffraction, fourier transform infrared, Raman and scanning electron microscopy techniques. x-ray diffraction results revealed that the prepared samples are nanocrystalline in nature with tetragonal structure. Fourier transform infrared spectroscopy analysis results showed the presence of Cu-O, Sn-O and Sn-S vibrations in the wavenumber range between 450 and 620 cm-1. Vibrational symmetry of prepared samples have been analyzed using Raman spectroscopy. Scanning electron microscopy analysis indicated the formation of flower like nanocrystals for samples prepared at various Ethylenediamine concentrations.


2014 ◽  
Vol 998-999 ◽  
pp. 1425-1428 ◽  
Author(s):  
Wen Ya Mei ◽  
Teng Hong Hui

Brewing spent diatomite (BSDT), a beer industrial by-product, was regenerated with calcination. The characteristics of regenerated BSDT were detected by X-ray diffraction, X-ray fluorescence, Fourier-transform infrared, and scanning electron microscopy. The results showed that the mineralization of the surface adsorbate and the remarkable increase in the Si-OH decreased the pHpzc value from 7.6 to 5.2 and increased the surface area from 36 m2/g to 52 m2/g after calcination at 800 °C. The results show that the regenerated BSTD could be employed as an efficient adsorbent for the recycling of BSDT.


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.


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