scholarly journals A New and Environmentally Friendly Route for Preparation of Carbon Microspheres from Wheat Straw

2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Chen Leishan ◽  
Wang Cunjing ◽  
Miao Yu ◽  
Chen Gairong

The reactions were performed to synthesize carbon materials using wheat straw powder as raw material. The wheat straw powder was first hydrolyzed at the absence of a catalyst at 190°C for 1 h, then the hydrolyzate solution was used as carbon source to prepare carbon materials via hydrothermal carbonization at 180°C in the absence of a catalyst for 8 h. The influence of solid-liquid-ratio of wheat straw to water on the morphology of the product was investigated. The samples were examined by a scanning electron microscope and Fourier transform infrared spectroscopy. The results show that the product was carbon microspheres with a large number of O–H, CHO, and other functional groups, and the diameters of carbon microspheres noticeably depended on the solid-liquid ratio. When the solid-liquid ratio was 1 : 60, the diameters of carbon microspheres were in the range of 100 to 300 nm when the solid-liquid ratio was 1 : 40, carbon microspheres with larger and more uniform diameters mostly about 250 nm were obtained, and when the solid-liquid-ratio was 1 : 20, there were more larger carbon microspheres with diameters about 800 nm in the product and the surface of these carbon microspheres is smoother, whereas; the uniformity of the product deteriorates.

2021 ◽  
Author(s):  
Youshan Sun ◽  
Xuyang Zhang ◽  
Fei Wang ◽  
Meiyan Wang

Abstract Calcium peroxide (CaO2) pretreatment was employed to remove lignin and subsequently facilitate enzymatic digestibility of wheat straw. An optimal condition was obtained at 130°C for 10 min with 0.35 g CaO2/g dried material of wheat straw and a 1:8 solid-liquid ratio. Under this condition, 57.8% of initial lignin, 7.2% of initial glucan, and 30.6% of initial xylan were removed from CaO2 pretreatment, respectively, meanwhile, a glucose recovery of 90.6 % and a xylose recovery of 65.9 % were obtained from the subsequent enzymatic hydrolysis of treated wheat straw, respectively. CaO2 pretreatment was proved to be a very effective method in delignification and improving enzymatic digestibility. Compared to raw material, the complex structure of lignocellulose was drastically disrupted with a wide emergence of scaly bulges and fully exposed microfibers, which still retained in the solid.


2014 ◽  
Vol 1033-1034 ◽  
pp. 114-118 ◽  
Author(s):  
Shang Xing Chen ◽  
Zong De Wang ◽  
Kai Fang ◽  
Guo Rong Fan ◽  
Peng Wang

The pretreatment of bamboo with dilute alkali and the effects on chemical components and enzymatic hydrolysis were studied, and the fiber structural properties of pretreated residues were studied with Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The results showed that dilute alkali was highly effective in delignification of the biomass, reducing the lignin content by 50-70%. Bamboo solid recovery was 74.40%, and cellulose, hemicellulose and lignin content were 60.02%, 25.93% and 9.08%, respectively, when pretreated with 1.0% sodium hydroxide, with a solid-liquid ratio of 1:10 at 100 °C for 40 min. Under the conditions, the pretreated residue was hydrolyzed for 72 h with cellulose and xylanase dosage 40 FPU/g cellulose, and the hydrolysis yield of cellulose was 81.38% and that of hemicelluloses was 84.78%, resulting in a total of 66.74 g fermentable sugars from 100 g dry bamboo. The SEM pictures indicated that the biomass structure was deformed and its fibers were exposed, and FTIR results verified the lignin removal by the pretreatment.


Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.


2012 ◽  
Vol 550-553 ◽  
pp. 1026-1029
Author(s):  
Jian Xi Ren ◽  
Jing Ya Li ◽  
Zhi Feng Cai ◽  
Jin Ming Dai ◽  
Mei Niu ◽  
...  

Carbon microspheres (CMSs) were used as the carrier to prepare the Ag-loading CMSs (Ag/CMSs) antibacterial agent through the method of chemical adsorption. The morphologies and structures of modified CMSs were characterized by using the field emission Scanning Electron Microscope (SEM). The results showed that silver was absorbed on the surface of CMSs. The bacterial inhibition ring experiment showed that Ag/CMSs had good antibacterial activity against Staphylococcus aureus and Escherichia coli, meanwhile the diameters of the bacterial inhibition rings were 19 mm against Staphylococcus aureus and 21 mm against Escherichia coli, respectively.


2012 ◽  
Vol 620 ◽  
pp. 384-388
Author(s):  
Sharifah Aishah Syed Salim ◽  
Julie Juliewatty Mohamed ◽  
Zainal Arifin Ahmad ◽  
Zainal Arifin Ahmad

Numerous methods have been used to produce high purity TiC. There is no previous study has been reported on the formation using single elemental powders of Titanium (Ti) and Carbon (C) with addition Nickel (Ni) by tungsten inert gas (TIG) weld method. In this work, TiC was synthesized via TIG method by arc melting elemental powder mixture of Ti and C at ~5 second (s) and 80 ampere (A). The effect Ni contents on TiC formation was investigated. The mixed raw material was ball milled for 24 hours followed by synthesis via TIG method. The arced samples were characterized by X-ray diffraction (XRD) and Scanning electron microscope (SEM). It was revealed, that small amount of Ni additive to the metal powder allows the production of dense and tough TiC.


2014 ◽  
Vol 881-883 ◽  
pp. 98-101
Author(s):  
Guang Qiang Li ◽  
Heng Hui Wang ◽  
Jian Yang ◽  
Jiang Hua Ma

In order to find a new way to utilize the high phosphorus oolitic hematite ore as raw material for steelmaking, the reduction and carburization of high phosphorus oolitic hematite by the gas of CH4-H2were studied. High phosphorus oolitic hematite, reduction and carburization products were investigated by the means of XRD and scanning electron microscope. The SEM-EDS and XRD analysis show that the main compositions of this ore are hematite and quartz, main microstructure is oolitic cluster with the zonal distribution of hematite and apatite, and iron carbide can be prepared from high phosphorus oolitic hematite.


2011 ◽  
Vol 311-313 ◽  
pp. 1535-1538 ◽  
Author(s):  
Hong Juan Wang ◽  
Hai Yan Xiao ◽  
Feng Qiang Sun ◽  
Jian Hua Zhang

Novel bio-based composites were developed from maleate castor oil (MACO) and lignin through free radical initiated copolymerization between MACO and diluent monomer styrene(St). The morphology and structure of the composites were characterized by Fourier transform infrared spectroscope (FTIR) and scanning electron microscope (SEM). The mechanical and thermal behaviors of the composites were investigated, which showed the incorporation of a little of lignin in the castor oil based polymer can enhance the tensile properties of the matrix polymer greatly. This work provides a facile route to prepare bio-based composite materials from castor oil and lignin and can be extended to prepare other bio-based materials from reproducible resources.


2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Xiujie Gong ◽  
Hongtao Zou ◽  
Chunrong Qian ◽  
Yang Yu ◽  
Yubo Hao ◽  
...  

Abstract Purpose The highly efficient degradation bacteria were selected from the humus from the very cold straw in China for many years to construct the in situ degradation bacteria, and the degradation efficiency of corn straw was determined by process optimization. Methods According to the main components of corn straw, through morphological, physiological, and biochemical screening, three highly efficient complementary degradation strains were selected to construct the compound flora, and the degradation efficiency was analyzed by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Result The corn straw selected in this paper is mainly composed of cellulose (31.99%), hemicellulose (25.33%), and lignin (14.67%). Through the determination of enzyme activity, strain Streptomyces sp. G1T has high decomposition ability to cellulose and hemicellulose but weak utilization ability to lignin; strain Streptomyces sp. G2T has the strongest decomposition ability to cellulose and hemicellulose among the three strains. The decomposition ability of strain Streptomyces sp. G3T to lignin was the strongest among the three strains. Therefore, by compounding the three strains, the decomposition ability has been greatly improved. The optimal process conditions obtained by single factor and response surface method are as follows: pH is 7, temperature is 30 °C, inoculation amount is 5%, rotational speed is 210 rpm, and the weight loss rate of straw is 60.55% after decomposing for 7 days. A large amount of degradation of corn straw can be seen by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Conclusion Streptomyces sp. G1T, Streptomyces sp. G2T, and Streptomyces sp. G3T screened from straw humus in very cold areas were used to construct in situ degradation bacteria, which had good straw degradation activity and had the potential to be used for straw treatment in cold areas after harvest. This characteristic makes the complex bacteria become a strong competitive candidate for industrial production, and it is also an effective biotechnology in line with the current recycling of resources.


2020 ◽  
Vol 16 (2) ◽  
pp. 12
Author(s):  
Solihudin Solihudin ◽  
Haryono Haryono ◽  
Atiek Rostika Noviyanti ◽  
Muhammad Rizky Ridwansyah

<p>Komposit forsterit-karbon merupakan salah satu material modifikasi dari forsterit yang berpotensi memiliki sifat isolator panas baik. Karbon dalam komposit dapat mengisi cacat titik pada kristal forsterit. Arang sekam padi (residu gasifikasi) mengandung SiO2 amorf dan karbon yang tinggi. Penelitian ini bertujuan menentukan pengaruh suhu kalsinasi dalam medium gas inert (dengan pengaliran gas argon) terhadap karakteristik komposit forsterit-karbon dari arang sekam padi dan magnesium karbonat. Metode penelitian meliputi preparasi arang sekam padi hasil gasifikasi, dan sintesis forsterit-karbon. Proses sintesis komposit forsterit karbon dilakukan dengan cara mencampurkan arang sekam padi dengan kalium karbonat pada rasio mol magmesium terhadap silikon sebesar 2 : 1 kemudian dikalsinasi dengan suhu divariasikan (700, 800, 900, dan 1000 oC). Selanjutnya sampel hasil sintesis dikarakterisasi dengan Fourier-transform infrared (FTIR), X-ray diffraction (XRD), dan scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). Hasil karakterisasi dengan FTIR dan XRD diperoleh kesimpulan bahwa forsterit mulai terbentuk pada suhu kalisiasi 800 oC dan sempurna pada suhu 1000 oC, karenanya komposit yang terbentuk pada 1000 oC dimungkinkan sebagai forsterit-karbon, di mana unsur-unsur yang terkandung ditunjukkan oleh SEM-EDS.</p><p> </p><p><strong>The Effect of Calcination Temperature on the Characteristics of Forsterite-Carbon Composites Synthesized in Argon Gas Medium</strong>. Forsterite-carbon composite is one of the material modifications of forsterite, which potentially has a good heat insulation property. Carbon in composites can fill point defects in forsterite crystals. Rice husk charcoal, as gasification residues, contains high amorphous SiO2 and carbon. This study aims to determine the effect of temperature on the calcination of a mixture of rice husk charcoal and magnesium carbonate under an inert gas (argon gas) on the characteristics of the forsterite-carbon composite produced. The experimental research performed includes the preparation of gasified rice husk charcoal and the synthesis of the carbon-forsterite composite. The synthesis process of the carbon-forsterite composites was carried out by mixing rice husk charcoal with potassium carbonate at a mole ratio of magnesium to silicon of 2 : 1. The mixture was then calcined with varying temperatures (700, 800, 900, and 1000 °C). Furthermore, the synthesized sample was characterized by Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS). The FTIR and XRD analysis show that the forsterites began to form at a calcination temperature of 800 °C and perfectly formed at a temperature of 1000 °C; therefore, the composite formed at 1000 °C is possible as forsterite-carbon, in which the contained elements were indicated by SEM-EDS.</p>


Author(s):  
Fitrianti Darusman ◽  
Sundani N Soewandhi ◽  
Rachmat Mauludin

Telah dilakukan kokristalisasi glimepirid (GMP) dengan asam oksalat (AO) menggunakan metode penggilingan dan pelarutan (menggunakan pelarut aseton). Diagram fase sistem biner GMP-AO digunakan untuk identifikasi awal pembentukan interaksi antar kedua komponen serta ditegaskan kembali dengan analisis mikroskopik menggunakan alat pemanas (hot stage) yang dihubungkan dengan mikroskop polarisasi. Padatan hasil kokristalisasi dikarakterisasi dengan metode analisis termal (Differential Scanning Calorymetry), difraktometri sinar-X serbuk (Powder X-Ray Diffraction), spektrofotometri inframerah (Fourier Transform-Infra Red) dan mikroskopi (Scanning Electron Microscope). Hasil identifikasi dan karakterisasi menunjukkan interaksi eutektik antara kedua fase kristalin GMP-AO dalam keadaan padat pada perbandingan molar 3:7, dengan titik eutektik pada temperatur 128,7°C. Selanjutnya, uji kelarutan dan laju disolusinya menggunakan media dapar fosfat pH 7,4. Kelarutan dan laju disolusi GMP hasil kokristalisasi meningkat dibandingkan dengan campuran fisika dan senyawa tunggalnya.Kata kunci : glimepirid, kokristalisasi, eutektik, kelarutan dan laju disolusi.


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