scholarly journals Polyamide-6 surface cracked forms nanofibers: A novel way for increasing the surface roughness, and porosity

Author(s):  
Sedigheh Aghayari

Abstract Here away used to reduce the porosity of the nanofibers, which is removing PVA nanofibers from PVA/PA6 nanofibers by water treatment. Measuring the porosity of the electrospun web before and after treatment by the BET method proved this. The specific surface area of the web was 60 % reduced after water treatment. Surface roughness and pore volume have reduced after water treatment. Also, I introduced BET as the method for measuring the diameters of mesopores (or lower than 100nm). I used BET to prove that the cracks can make mesopores on the nanofibers.

2021 ◽  
Author(s):  
Sedigheh Aghayari

Abstract Here a way used to reduce the porosity of the electrospun web which removed PVA nanofibers from PVA/PA6 hybrid nanoweb by water treatment. Measuring the porosity of the electrospun web before and after treatment by BET method and image processing, proved this. The specific surface area of the web 70 % reduced after water treatment.


Author(s):  
Sedigheh Aghayari

One of the main properties of nanofiber webs is their porosity, and any application needs its porosity value. There are many applications which they high or low porosities. Electrospinning is a way to get high porosity, but in some applications, higher or lower porosities than electrospun webs are needed. Up to now, removing one part of the nanofiber web has been used to change the porosity. Here, a new way is introducing for reducing the porosity of the nanowebs, which chose a hydrophilic nanofiber as one part. In the past, only hydrophobic one’s use. We can get the visa versa results. Here a way used to reduce the porosity of the electrospun web which removed PVA nanofibers from PVA/PA6 hybrid nanoweb by water treatment. Measuring the porosity of the electrospun web before and after treatment by the BET method, density method, and image processing proved this. The specific surface area of the web was 70 % reduced after water treatment. After water treatment, the surface roughness and pore volume reduce. Also, the best way introduced for measuring the porosity. Image processing introduces as the best method for measuring the porosity of the nanowebs.


2012 ◽  
Vol 454 ◽  
pp. 179-182
Author(s):  
Jun Tao Chen ◽  
Shu Fang Ding ◽  
Chun Hua Bai ◽  
Hui Ping Wang ◽  
Yan Xu

Fly ash roasted by different temperature, XRD analysis of fly ash after roasting, specific surface area and pore properties of fly ash roasted before and after were tested. Results showed that roasting influenced significantly on pore properties of fly ash; Specific surface area, pore volume and amount of middle pore of fly ash increased with roasting temperature increased , then reached maximum at 700 °C, and decreased with roasting temperature increased.


2017 ◽  
Vol 68 (3) ◽  
pp. 483-486
Author(s):  
Constantin Sorin Ion ◽  
Mihaela Bombos ◽  
Gabriel Vasilievici ◽  
Dorin Bombos

Desulfurisation of atmospheric distillation gasoline and gas oil was performed by adsorption process on Fe/ bentonite. The adsorbent was characterized by determining the adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments of atmospheric distillation gasoline and gas oil were performed in continuous system at 280�320oC, 5 atm and volume hourly space velocities of 1�2 h-1. The efficiency of adsorption on Fe / bentonite was better at desulphurisation of gasoline versus gas oil.


Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Chenlong Ding ◽  
Jinxian He ◽  
Hongchen Wu ◽  
Xiaoli Zhang

Ordos Basin is an important continental shale gas exploration site in China. The micropore structure of the shale reservoir is of great importance for shale gas evaluation. The Taiyuan Formation of the lower Permian is the main exploration interval for this area. To examine the nanometer pore structures in the Taiyuan Formation shale reservoirs in the Lin-Xing area, Northern Shaanxi, the microscopic pore structure characteristics were analyzed via nitrogen adsorption experiments. The pore structure parameters, such as specific surface area, pore volume, and aperture distribution, of shale were calculated; the significance of the pore structure for shale gas storage was analyzed; and the main controlling factors of pore development were assessed. The results indicated the surface area and hole volume of the shale sample to be 0.141–2.188 m2/g and 0.001398–0.008718 cm3/g, respectively. According to the IUPAC (International Union of Pure and Applied Chemistry) classification, mesopores and macropores were dominant in the pore structure, with the presence of a certain number of micropores. The adsorption curves were similar to the standard IV (a)-type isotherm line, and the hysteresis loop type was mainly similar to H3 and H4 types, indicating that most pores are dominated by open type pores, such as parallel plate-shaped pores and wedge-shaped slit pores. The micropores and mesopores provide the vast majority of the specific surface area, functioning as the main area for the adsorption of gas in the shale. The mesopores and macropores provide the vast majority of the pore volume, functioning as the main storage areas for the gas in the shale. Total organic carbon had no notable linear correlation with the total pore volume and the specific surface area. Vitrinite reflectance (Ro) had no notable correlation with the specific surface area, but did have a low “U” curve correlation with the total pore volume. There was no relationship between the quartz content and specific surface area and total pore volume. In addition, there was no notable correlation between the clay mineral content and total specific surface area and total pore volume.


2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the


2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.


BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 729-746
Author(s):  
Junhong Zhang ◽  
Zhi-jun He ◽  
Qing Guo ◽  
De-chao Xiao ◽  
Wen-long Zhan

Microwave modification of activated coke is reported as a green and simple route to improve its synergistic desulfurization and denitrification. The results showed that microwave irradiation improved the specific surface area and pore volume, decreased the pore size, and activated the surface functional groups of the activated coke. Under the conditions of a microwave power of 500 W and a modification time of 30 min, the specific surface area was increased from 185.9 m2/g to 351.7 m2/g, the pore volume increased from 0.042 m3/g to 0.111 m3/g, and the characteristic peak strengths of C=C and -OH drastically increased. When the reaction temperature was 140 °C and the O2 concentration was 10% (by volume), the desulfurization and denitrification efficiency were maintained at levels greater than 90% and 80% for 30 min and 15 min, respectively. The C-O content increased, and the C=C and -OH content decreased after undergoing desulfurization and denitrification. The desulfurization and denitrification products were primarily sulfate and nitrate. This provides theoretical support for the application of microwave modified active coke in low temperature desulfurization and denitrification.


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