scholarly journals Electrospinning Nanofibres of Pullulan Extracted From Phylloplane Fungus, Aureobasidium Pullulans

2020 ◽  
Author(s):  
Komal Saraf ◽  
N Vigneshwaran

Abstract Aureobasidium pullulans isolated from the phylloplane of Peltophorum tree, produced pullulan, 24 an extracellular polysaccharide. It was grown on three different carbon sources, sucrose, wheat 25 bran and cotton stalk dust, for maximizing the pullulan yield. A. pullulans (67.4 gL-1) had the 26 highest yield followed by A. pullulans MTCC 1991 (63.68 gL-1). Pullulan was characterized by 27 X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area analyzer, DSC and NMR. 28 Electrospinning of pullulan blended with poly (vinyl alcohol) (PVA) produced bead-less 29 nanofibres. The optimized parameters for electrospinning were 25 kV applied voltage, 0.5 mL/h 30 flow rate, 18% polymer concentration (pullulan + PVA) and 150 mm tip-to-collector distance. 31 The pullulan nanofibre was characterized by SEM, AFM, BET, contact angle measurement, DSC 32 and CIE color space analyzer. A maximum surface area of 183.4 m2/g while the minimum 33 nanofibre diameter (79 ± 19 nm by SEM) was obtained for the electrospun mat of commercial 34 pullulan + 40% PVA. This work signifies the importance of pullulan extracted from an isolate of 35 Peltopohorum tree for conversion to high surface area nanofibres by electrospinning process.

2020 ◽  
Author(s):  
Komal Saraf ◽  
N Vigneshwaran

Abstract Aureobasidium pullulans isolated from the phylloplane of Peltophorum tree, produced pullulan, an extracellular polysaccharide. It was grown on three different carbon sources, sucrose, wheat bran and cotton stalk dust, for maximizing the pullulan yield. A. pullulans (67.4 gL-1) had the highest yield followed by A. pullulans MTCC 1991 (63.68 gL-1). Pullulan was characterized by X-ray diffractometer (XRD), Brunauer-Emmett-Teller (BET) surface area analyzer, DSC and NMR. Electrospinning of pullulan blended with poly (vinyl alcohol) (PVA) produced bead-less nanofibres. The optimized parameters for electrospinning were 25 kV applied voltage, 0.5 mL/h flow rate, 18% polymer concentration (pullulan + PVA) and 150 mm tip-to-collector distance. The pullulan nanofibre was characterized by SEM, AFM, BET, contact angle measurement, DSC and CIE color space analyzer. A maximum surface area of 183.4 m2/g while the minimum nanofibre diameter (79 ± 19 nm by SEM) was obtained for the electrospun mat of commercial pullulan + 40% PVA. This work signifies the importance of pullulan extracted from an isolate of Peltopohorum tree for conversion to high surface area nanofibres by electrospinning process.


2021 ◽  
Author(s):  
Emmanuel Ayodele ◽  
Victoria Ezeagwula ◽  
Precious Igbokwubiri

Abstract Bamboo trees are one of the fastest growing trees in tropical rainforests around the world, they have various uses ranging from construction to fly ash generation used in oil and gas cementing, to development of activated carbon which is one of the latest uses of bamboo trees. This paper focuses on development of activated carbon from bamboo trees for carbon capture and sequestration. The need for improved air quality becomes imperative as the SDG Goal 12 and SDG Goal13 implies. One of the major greenhouse gases is CO2 which accounts for over 80% of greenhouse gases in the environment. Eliminating the greenhouse gases without adding another pollutant to the environment is highly sought after in the 21st century. Bamboo trees are mostly seen as agricultural waste with the advent of scaffolding and other support systems being in the construction industry. Instead of burning bamboo trees or using them for cooking in the local communities which in turn generates CO2 and fly ash, an alternative was considered in this research work, which is the usage of bamboo trees to generate activated, moderately porous and high surface area carbon for extracting CO2 from various CO2 discharge sources atmosphere and for water purification. This paper focuses on the quality testing of activated carbon that can effectively absorb CO2. The porosity, pore volume, bulk volume, and BET surface area were measured. The porosity of the activated carbon is 27%, BET surface area as 1260m²/g. Fixed carbon was 11.7%, Volatility 73%, ash content 1.7%.


2011 ◽  
Vol 23 (8) ◽  
pp. 2062-2067 ◽  
Author(s):  
Junjiang Zhu ◽  
Kamalakannan Kailasam ◽  
Xiao Xie ◽  
Reinhard Schomaecker ◽  
Arne Thomas

2018 ◽  
Vol 44 ◽  
pp. 00165 ◽  
Author(s):  
Karolina Sobczyk ◽  
Karol Leluk

Poly(lactic acid) electrospinning tests were carried out under various process conditions. Openwork structures with a high surface area to weight ratio have been obtained. Changing the parameters of the PLA electrospinning process resulted in products with different fiber morphology.


RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.


2014 ◽  
Vol 1058 ◽  
pp. 25-29
Author(s):  
Shi Jing Lin ◽  
Wu Tong Du ◽  
Ting Ting Ding ◽  
Yu Zhao ◽  
You Zhao ◽  
...  

Flower-like Co–La oxide micro/nanomaterials have been synthesized via an ethylene-glycol-mediated process, under the condition of that the mole ratio of lanthanum nitrate (La (NO3)3·6H2O) and cobalt nitrate (Co (NO3)2·6H2O) was 1:1 (based on the amount of Co (NO3)2·6H2O 0.002 mol), the dosage of urea was 2.2 g, the dosage of tetra-butyl ammonium bromide (TBAB) was 6.0 g, with magnetic stirring heating under 170 °C for 60 minutes in the 150mL ethylene glycol, the prepared precursors of Co–La oxides have regular flower-like morphology, in addition, the amount of TBAB and urea plays a significant role on the synthesis of the precursors. The flower-like Co–La oxides micro/nanomaterials were prepared after the precursors were calcinated in the muffle furnace at 800 °C for 2 h, the morphology, crystal properties and element distribution of the products were investigated by the analysis of SEM-EDX, XRD and BET, etc. The structures of these products with regular flower-like morphology are on the micrometer scale, which are hierarchically composed of nanosized building blocks, with highly polycrystalline nature, and the Brunauer–Emmett–Teller (BET) surface area of 68.5 m2/g. Therefore, those micro/nanomaterials have been developed as promising catalytic materials for their not only keeping the high surface area of nanomaterials, but effectively inhibiting aggregation.


Holzforschung ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 367-374 ◽  
Author(s):  
Yuxiang Huang ◽  
Wenji Yu ◽  
Guangjie Zhao

AbstractA novel way to prepare mesoporous activated carbon fibers (ACFs-P) has been developed, while the ACFs-P with high surface area were obtained from liquefied wood by combining polyvinyl butyral (PVB) blending and steam activation. The porosity properties of the new material was investigated by N2adsorption and the Brunauer–Emmett–Teller (BET) surface area was found to be 2710 m2g−1and a pore volume of 1.540 cm3g−1, of which 58.2% was mesoporous with diameters between 3 and 6 nm. ACFs-P had a higher methylene blue (MB) adsorption capacity (962 mg/g) than the PVB-added carbon fibers (CFs-P) and ACFs-P without PVB (ACFs-C). Flexible all-carbon yarn supercapacitors can be produced from ACFs-P as powder or fiber. The fiber approach led to yarn supercapacitors with a less favorable electrochemical performance than the powder based production owing to the poor strength of the fibers. A 10 cm long yarn supercapacitor from the powdered ACFs exhibited a high specific length capacitance of 43 mF cm−1at 2 mV s−1. Yarn supercapacitors showed an excellent mechanical flexibility and its capacitor properties were not diminished after bending or crumpling.


2010 ◽  
Vol 148-149 ◽  
pp. 1096-1099
Author(s):  
Gong Ming Peng ◽  
De Lian Yi ◽  
Lin Wu ◽  
Zhao Hui Ou Yang ◽  
Jian Guo Wang

Novel base catalysts were obtained by subjecting Y zeolites to nitridation. These materials were characterized by elemental analysis, X-ray diffraction, BET surface area analysis, In situ diffuse reflectance infrared fourier transform Spectroscopy (in situ DRIFTS), Pyrrole adsorption. The results indicated nitrogen-incorporated NaY zeolite was well ordered and possess high surface area and pore volume. In situ DRIFTS experiments confirmed that N atoms had been introduced into the framework by nitridation to form -NH2- or -NH- species. It was found that Lewis basicity of these oxynitride materials increased by the pyrrole adsorption. Furthmore, the basic catalytic properties of nitrogen-incorporated zeolites were evaluated by Knoevenagal condensation of benzaldehyde with diethyl malonate and enhanced yield of product was achieved.


2016 ◽  
Vol 857 ◽  
pp. 475-479 ◽  
Author(s):  
M.S. Mohammed Yahya ◽  
Jeyashelly Andas ◽  
Ghani Zaidi Ab

In this work, mesoporous activated carbon with high surface area was synthesized from swamp taro stalk by single step ZnCl2 activation. The synthesized activated carbon was characterized by Na2S2O3 volumetric method, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and N2 adsorption-desorption analyses. Under the single step ZnCl2 activation, the registered iodine number, BET surface area, total pore volume and pore diameter were 1087.57 mgg-1, 1242.26 m2g-1, 0.73cm3g-1 and 3.72 nm respectively with yield of 25.34%. SEM analysis evidenced the well-formation of porous structure. Type IV isotherm with H2 loops obtained from N2-sorption studies indicates the ink bottles shape mesoporous network structure. This research proved the successful conversion of plant waste into high grade activated carbon.


2012 ◽  
Vol 66 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Ş. Gül ◽  
O. Eren ◽  
Ş. Kır ◽  
Y. Önal

The objective of this study is to compare the performances of catalytic ozonation processes of two activated carbons prepared from olive stone (ACOS) and apricot stone (ACAS) with commercial ones (granular activated carbon-GAC and powder activated carbon-PAC) in degradation of reactive azo dye (Reactive Red 195). The optimum conditions (solution pH and amount of catalyst) were investigated by using absorbencies at 532, 220 and 280 nm wavelengths. Pore properties of the activated carbon (AC) such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N2 adsorption. The highest BET surface area carbon (1,275 m2/g) was obtained from ACOS with a particle size of 2.29 nm. After 2 min of catalytic ozonation, decolorization performances of ACOS and ACAS (90.4 and 91.3%, respectively) were better than that of GAC and PAC (84.6 and 81.2%, respectively). Experimental results showed that production of porous ACs with high surface area from olive and apricot stones is feasible in Turkey.


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