scholarly journals Characterization of cellulose nanocrystalline isolated from banana peduncles using acid hydrolysis

2021 ◽  
Vol 922 (1) ◽  
pp. 012072
Author(s):  
Ratna ◽  
S Aprilia ◽  
N Arahman ◽  
A A Munawar

Abstract The study aimed to characterize cellulose nanocrystalline (NCCs) from banana peduncles using acid hydrolysis. The NCCs isolation process was done by hydrolysis using H2SO4 with concentrations of 1M, 2M, and 3M at a microwave power of 100 Watts within 1 hour of hydrolysis. The product of NCCs was characterized in term of yield, chemical composition (by FTIR), and its crystallinity. The result showed that the highest yield of 88.33% was obtained in acid hydrolysis at the concentration of 1M H2SO4. The results of the FTIR test showed that non-cellulose content had been removed and demonstrated that the molecular structure of cellulose does not change even when treated at different acid concentrations. X-Ray Diffraction analysis showed that crystallinity decreased by increasing the sulfamic acid concentration. The thermogravimetric analysis confirmed the heat resistance analysis and showed that the NCCs is gradually decomposed at a temperature range of 268.3–415.25 ¼C. The colour of cellulose nanocrystalline powder darkens as the sulfuric acid concentration increases.

2017 ◽  
Vol 264 ◽  
pp. 9-12 ◽  
Author(s):  
Pei Gie Gan ◽  
Sung Ting Sam ◽  
Muhammad Faiq bin Abdullah ◽  
Nik Noriman bin Zulkepli ◽  
Yin Fong Yeong

In recent years, there has been a great interest in the production of nanocrystalline cellulose (NCC) due to its excellent properties. In this study, empty fruit bunch (EFB) was used as the material for the production of NCC due to its high cellulose content, inexpensive and readily-available source. NCC was prepared using acid hydrolysis at 62% for 1 hours. The morphology of NCC was determined by Field Emission Scanning Electron Microscopy (FESEM). The size of NCC was less than 50 nm in width. The obtained NCC was also characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). FTIR spectra analysis showed that hemicellulose and lignin were mostly removed from the EFB after bleaching and alkaline pre-treatment. XRD diffractograms revealed that EFB nanocellulose showed a crystallinity improvement of 24.3% compared to raw EFB cellulose.


2021 ◽  
Vol 11 (1) ◽  
pp. 84-106
Author(s):  
Nada Sadoon Ahmed zeki ◽  
Sattar Jalil Hussein ◽  
Khalifa K. Aoyed ◽  
Saad Kareem Ibrahim ◽  
Ibtissam K. Mehawee

This work deals with the hydrodesulfurization of three types of naphtha feedstocks; mixednaphtha (WN), heavy naphtha (HN) & light naphtha (LN) with a sulfur content of 1642.1,1334.9 & 709 ppm respectively, obtained from Missan refinery using prepared Co-Mo/γ-Al2O3catalyst. The Iraqi white kaolin was used as a starting material for the preparation of γ-Al2O3support, transferring kaolin to meta-kaolin was studied through calcination at differenttemperatures and durations, kaolin structure was investigated using X-Ray diffractiontechniques.High purity 94.83%. Crystalline γ-Al2O3 with a surface area of 129.91 m2/gm, pore volume0.9002 cm3/g was synthesized by extraction of Iraqi kaolin with H2SO4 at different acid to clayweight ratios, acid concentrations & leaching time. Ethanol was used as precipitating agent; theresultant gel was dried and calcined at 70OC, 10 hrs & 900 OC, 2 hrs respectively.The effects of different parameters on the average crystallinity and extraction % ofsynthesized γ-Al2O3 were studied like; acid: clay ratio, sulfuric acid concentration, leachingtime, leaching temperature & kaolin conversion to metakaolin. Characterization of prepared γ-Al2O3 & Co-Mo catalyst were achieved by X-ray diffraction, FTIR-spectra, texture properties& BET surface area, BJH N2 adsorption porosity, AFM, SEM, crush strength & XRF tests. Co-Mo/ γ-Al2O3 catalyst with final loading 5.702 wt% and 21.45 wt% of Co and Mo oxidesrespectively was prepared by impregnation methods.The activity of prepared Co-Mo/γ-Al2O3 catalyst after moulding to be tested forhydrodesulfurization (HDS) of naphtha feedstock W.N, H.N & L.N was performed using apilot hydrotreating unit at petroleum research & development centre, at different operatingconditions. Effects of temperature, LHSV, pressure, time & pore size distribution were studied,the best percentage of sulfur removal is increased with decreasing LHSV to 2 hr-1 as a generaltrend to be 89.71, 99.72, 99.20 % at 310oC for the whole naphtha, heavy naphtha and lightnaphtha feedstocks respectively, at 34 bar pressure and 200/200 cm3/cm3 H2/HC ratio.


Author(s):  
ROGER GUILARD ◽  
VIRGINIE PICHON-PESME ◽  
HASSANE LACHEKAR ◽  
CLAUDE LECOMTE ◽  
ALLY M. AUKAULOO ◽  
...  

The synthesis and characterization of three monomeric aluminum porphycenes with anionic or σ-bonded axial ligands is reported. The investigated compounds are represented as ( EtioPc ) Al ( CH 3) and ( EtioPc ) AlX where EtioPc represents the dianion of etioporphycene and X = Cl − or OH −. Each synthesized complex was characterized by mass spectrometry. 1 H NMR, IR and UV-visible spectroscopies as well as by electrochemistry. Comparisons are made between the properties of complexes in the aluminum etioporphycene series and related chloro- or methyl σ-bonded Al ( III ) porphyrins containing octaethylporphyrin ( OEP ) or tetraphenylporphyrin ( TPP ) macrocycles. Comparisons are also made between the currently investigated compounds and a previously reported Al ( III ) μ-oxo dimer, [( EtioPc ) Al ]2 O . In addition, the crystal and molecular structure of ( EtioPc ) Al ( CH 3) was determined by X-ray diffraction. The molecular structure of this methyl-σ-bonded aluminum etioporphycene provides the first structural data for an aluminum porphycene compound. The aluminum(III) atom in ( EtioPc ) Al ( CH 3) is pentacoordinated and is located 0.54 Å from the plane of the four N -nitrogens.


2007 ◽  
Vol 62 (3) ◽  
pp. 427-438 ◽  
Author(s):  
Vincenzo G. Albano ◽  
Luigi Busetto ◽  
Fabio Marchetti ◽  
Magda Monari ◽  
Stefano Zacchini ◽  
...  

The diiron aminocarbyne complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (R = Xy1, 1a; R = Me, 1b; R = CH2Ph, 1c; Xy1 = 2,6-Me2C6H3) undergo replacement of the coordinated nitrile by halides, diethyldithiocarbamate, and dicyanomethanide to give [Fe2{μ-CN(Me) (R)}(μ-CO)(CO)(X)(Cp)2] complexes (R = Me, X = Br, 4a; R = Me, X = I, 4b; R = CH2Ph, X = Cl, 4c; R = CH2Ph, X = Br, 4d; R = CH2Ph, X = I, 4e; R = Xy1, X = SC(S)NEt2, 5a; R = Me, X = SC(S)NEt2, 5b; R = Xy1, X = CH(CN)2, 7), in good yields. The molecular structure of 5a shows an unusual η1 coordination mode of the dithiocarbamate ligand. Similarly, treatment of [M2{μ-CN(Me) (R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (M = Fe, R = Xy1, 1a; M = Fe, R = Me, 1b; M = Ru, R = Xy1, 2a; M = Ru, R = Me, 2b) with a series of phosphanes generates the cationic complexes [M2{μ- CN(Me)(R)}(μ-CO)(CO)(P)(Cp)2][SO3CF3] (M = Fe, R = Xy1, P = PPh2H, 6a; M = Fe, R = Xy1, P = PPh3, 6b; M = Fe, R = Xy1, P = PMe3, 6c; M = Fe, R = Me, P = PMe2Ph, 6d; M = Fe, R = Me, P = PPh3, 6e; M = Fe, R = Me, P = PMePh2, 6f; M = Ru, R = Xy1, P = PPh2H, 6g; M = Ru, R = Me, P = PPh2H, 6h), in high yields. The molecular structure of 6a has been elucidated by an X-ray diffraction study. The reactions of [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO)(NCR′)(Cp)2][SO3CF3] [R′ = Me, 1a; R′ = tBu, 3] with PhLi and PPh2Li yield [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(Ph)(Cp)2] (8) and [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(PPh2)(Cp)2] (9), respectively. The molecular structure of 8 has been ascertained by X-ray diffraction. Conversely, the reaction of 1a with MeLi generates the aminoalkylidene compound [Fe2{C(Me)N(Me)(Xy1)}(μ-CO)2(CO)(Cp)2] (10).Finally, the acetone complex [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(OCMe2)(Cp)2][SO3CF3] (12) reacts with lithium acetylides to give complexes [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(C≡CR)(Cp)2] (R = p-C6H4Me, 11a; R = Ph, 11b; R = SiMe3, 11c), in high yields. Filtration through alumina of a solution of 11a in CH2Cl2 results in hydration of the acetylide group and C-Si bond cleavage, affording [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO){C(O)Me}(Cp)2] (12).


2020 ◽  
Vol 1010 ◽  
pp. 495-500
Author(s):  
Nurfarah Aini Mocktar ◽  
Mohammad Khairul Azhar Abdul Razab ◽  
An'amt Mohamed Noor ◽  
Nor Hakimin Abdullah

Acid hydrolysis method become one of the attention among researcher to produce high degree nanocellulose. Integration of sonication process was used to stir and mix particles in an element for different stages. This paper revealed the surface morphology and crystallinity index of two organic plant that were kenaf and oil palm nanocellulose. Characterization of the nanocellulose were identified by 2 techniques; (1) field emission scanning electron microscope (FESEM) that provides surface morphology and elemental information of the element, (2) x-ray diffraction (XRD) for phase identification of materials crystallinity. The result showed that the properties of nanocellulose increase after sonication method have been integrated.


2014 ◽  
Vol 69 (6) ◽  
pp. 737-741 ◽  
Author(s):  
Gustavo A. Echeverría ◽  
Oscar E. Piro ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

Ammonium acesulfamate, (NH4)C4H4NO4S, was prepared by the reaction of acesulfamic acid and ammonium carbonate in aqueous solution, and characterized by elemental analysis and 1H and 13C NMR spectroscopy. Its crystal and molecular structure was determined by single-crystal X-ray diffraction methods. The substance crystallizes in the orthorhombic space group Pnma with Z = 4 molecules per unit cell. The NH4+ ion generates medium to strong hydrogen bonds with the carbonylic oxygen, the iminic nitrogen and the sulfonyl oxygen atoms of the acesulfamate anion. The FTIR spectrum of the compound was also recorded and is briefly discussed.


2021 ◽  
Vol 99 (2) ◽  
pp. 259-267
Author(s):  
Serge Ruccolo ◽  
Erika Amemiya ◽  
Daniel G. Shlian ◽  
Gerard Parkin

The silatrane hydride compound, [N(CH2CH2O)3]SiH, reacts with CO2 in the presence of the [tris(2-pyridylthio)methyl]zinc hydride complex, [Tptm]ZnH, to afford the silyl formate and methoxide derivatives, [N(CH2CH2O)3]SiO2CH and [N(CH2CH2O)3]SiOCH3. The molecular structure of [N(CH2CH2O)3]SiO2CH has been determined by X-ray diffraction, thereby demonstrating that the formate ligand adopts a distal conformation in which the uncoordinated oxygen atom resides with a trans-like disposition relative to silicon. Density functional theory calculations indicate that the atrane motif of [N(CH2CH2O)3]SiO2CH is flexible, such that the energy of the molecule changes relatively little as the Si···N distance varies over the range 2.0–3.0 Å.


2009 ◽  
Vol 64 (4) ◽  
pp. 467-469 ◽  
Author(s):  
Thomas M. Klapötke ◽  
Matthias Scherr ◽  
Burkhard Krumm

The first triorganosulfonium azides [Me3S]N3 and [Ph3S]N3 were prepared by reaction of the corresponding sulfonium bromides/iodides with silver azide and characterized by spectroscopic methods. The molecular structure of [Ph3S]N3 as well as that of the precursor, [Ph3S]Br, have been determined by X-ray diffraction.


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