Surface Characterization of Poly(acrylonitrile) Membranes Graft-Polymerized with Ionic Monomers As Revealed by ζ Potential Measurement

1998 ◽  
Vol 31 (4) ◽  
pp. 1277-1284 ◽  
Author(s):  
Toshihiko Jimbo ◽  
Mitsuru Higa ◽  
Norihiko Minoura ◽  
Akihiko Tanioka
2020 ◽  
Vol 12 (12) ◽  
pp. 4880
Author(s):  
Cecilia Hodúr ◽  
Naoufal Bellahsen ◽  
Edit Mikó ◽  
Virág Nagypál ◽  
Zita Šereš ◽  
...  

Agricultural wastewater poses serious risks to the environment due to how it is injudiciously used and managed. We investigated the use of pomegranate peel powder (PPP) to adsorb ammonium ions from milking parlor wastewater, which is applied as a nitrogen source for cropland fertilization despite its environmental ramifications. As a valueless by-product of juice and jam industries, PPP shows promising features and characteristics as a potential bio-adsorbent for ammonium nitrogen removal and recovery. The surface characterization of PPP was performed by zeta potential measurement and attenuated total reflectance Fourier transform infrared Spectroscopy (ATR-FTIR) analysis. The adsorption studies were carried out by batch experiments where the initial ammonium nitrogen (NH4–N) concentration of studied wastewater was 80 mg/L. The effects of different operational parameters, such as pH, adsorbent dose, contact time, stirring speed, and temperature, were investigated. From kinetic studies, the equilibrium time was found to be 120 min, achieving an 81.8% removal synonym of ~2.5 mg/g NH4–N uptake. The adsorption isotherm data fitted well with Langmuir model with correlation (R2) > 0.99. Meanwhile, the kinetics followed pseudo-second order model with correlation (R2) > 0.99.


1996 ◽  
Vol 31 (23) ◽  
pp. 6305-6315 ◽  
Author(s):  
M. Desaeger ◽  
M. J. Reis ◽  
A. M. Botelho do Rego ◽  
J. D. Lopes da Silva ◽  
I. Verpoest

Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Langmuir ◽  
2008 ◽  
Vol 24 (17) ◽  
pp. 9500-9507 ◽  
Author(s):  
Claudia Kolbeck ◽  
Manuela Killian ◽  
Florian Maier ◽  
Natalia Paape ◽  
Peter Wasserscheid ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 869
Author(s):  
Minghua Wei ◽  
Shaopeng Wu ◽  
Haiqin Xu ◽  
Hechuan Li ◽  
Chao Yang

Steel slag is the by-product of the steelmaking industry, the negative influences of which prompt more investigation into the recycling methods of steel slag. The purpose of this study is to characterize steel slag filler and study its feasibility of replacing limestone filler in asphalt concrete by evaluating the resistance of asphalt mastic under various aging methods. Firstly, steel slag filler, limestone filler, virgin asphalt, steel slag filler asphalt mastic and limestone filler asphalt mastic were prepared. Subsequently, particle size distribution, surface characterization and pore characterization of the fillers were evaluated. Finally, rheological property, self-healing property and chemical functional groups of the asphalt mastics with various aging methods were tested via dynamic shear rheometer and Fourier transform infrared spectrometer. The results show that there are similar particle size distributions, however, different surface characterization and pore characterization in the fillers. The analysis to asphalt mastics demonstrates how the addition of steel slag filler contributes to the resistance of asphalt mastic under the environment of acid and alkaline but is harmful under UV radiation especially. In addition, the pore structure in steel slag filler should be a potential explanation for the changing resistance of the asphalt mastics. In conclusion, steel slag filler is suggested to replace limestone filler under the environment of acid and alkaline, and environmental factor should be taken into consideration when steel slag filler is applied to replace natural fillers in asphalt mastic.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 992
Author(s):  
Suchitha Devadas ◽  
Saja M. Nabat Al-Ajrash ◽  
Donald A. Klosterman ◽  
Kenya M. Crosson ◽  
Garry S. Crosson ◽  
...  

Lignin macromolecules are potential precursor materials for producing electrospun nanofibers for composite applications. However, little is known about the effect of lignin type and blend ratios with synthetic polymers. This study analyzed blends of poly(acrylonitrile-co-methyl acrylate) (PAN-MA) with two types of commercially available lignin, low sulfonate (LSL) and alkali, kraft lignin (AL), in DMF solvent. The electrospinning and polymer blend solution conditions were optimized to produce thermally stable, smooth lignin-based nanofibers with total polymer content of up to 20 wt % in solution and a 50/50 blend weight ratio. Microscopy studies revealed that AL blends possess good solubility, miscibility, and dispersibility compared to LSL blends. Despite the lignin content or type, rheological studies demonstrated that PAN-MA concentration in solution dictated the blend’s viscosity. Smooth electrospun nanofibers were fabricated using AL depending upon the total polymer content and blend ratio. AL’s addition to PAN-MA did not affect the glass transition or degradation temperatures of the nanofibers compared to neat PAN-MA. We confirmed the presence of each lignin type within PAN-MA nanofibers through infrared spectroscopy. PAN-MA/AL nanofibers possessed similar morphological and thermal properties as PAN-MA; thus, these lignin-based nanofibers can replace PAN in future applications, including production of carbon fibers and supercapacitors.


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