scholarly journals The Application of Polymer Inclusion Membranes Based on CTA with 1-alkylimidazole for the Separation of Zinc(II) and Manganese(II) Ions from Aqueous Solutions

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 242 ◽  
Author(s):  
Elzbieta Radzyminska-Lenarcik ◽  
Malgorzata Ulewicz

Polymer cellulose triacetate membranes doped with 1-alkylimidazole as fixed carriers were applied for the investigation of the facilitated transport of Zn(II) and Mn(II) ions from an aqueous sulphate feed phase (cM = 0.001 mol/dm3). For the polymer inclusion membranes (PIMs) doped with 1-alkylimidazole (alkyl – from hexyl up to decyl), the following patterns of transport selectivity were found: Zn(II) > Mn(II). The highest initial flux of Zn(II) ions (2.65 µmol/m2·s) was found for PIMs doped with 1-decyl-imidazole, whereas the best Zn(II)/Mn(II) selectivity coefficients equal to 19.7 were found for 1-hexyl-imidazole. Permeability coefficients for Zn(II) and Mn(II) ions transported across PIMs increase with an increase in the pKa values of 1-alkylimidazole. The polymer membranes of cellulose triacetate-o-NPPE with 1-alkylimidazole were characterised by scanning electron microscopy, non-contact atomic force microscopy and thermal analysis techniques. The influence of membrane morphology on the Zn(II) and Mn(II) transport process was discussed.

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 88 ◽  
Author(s):  
Elzbieta Radzyminska-Lenarcik ◽  
Ilona Pyszka ◽  
Malgorzata Ulewicz

Polymer inclusion membranes (PIMs) doped with ethylenodiamino-bis-acetylacetone as fixed carrier was applied for the investigation of the facilitated transport of Zn(II), Cr(III), and Ni(II) ions from an aqueous nitrate feed phase (cM = 0.001 mol/dm3). The optimal membrane composition (amount of carrier and o-NPPE-plasticizer) was determined. For the optimal polymer inclusion membranes doped with ethylenodiamino-bis-acetylacetone, the following patterns of transport selectivity were found: Zn(II) > Cr(III) > Ni(II). The initial flux of Zn(II), Cr(III), and Ni(II) ions was 6.37 µmol/m2∙s, 5.53 µmol/m2∙s, and 0.40 µmol/m2∙s, respectively. The selectivity coefficients equal to 1.2 and 15.9 were found for Zn(II)/Cr(III) and Zn(II)/Ni(II), respectively. After 24-h transport, the recovery factor of Zn(II), Cr(III), and Ni(II) were 90%, 65%, and 6%, respectively. The polymer inclusion membranes doped with ethylenodiamino-bis-acetylacetone were characterized by scanning electron microscopy and non-contact atomic force microscopy. The influence of membrane morphology on transport process was discussed.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1780 ◽  
Author(s):  
Radzyminska-Lenarcik ◽  
Ulewicz

The study involved the transport of zinc(II), cadmium(II), and nickel(II) ions from acidic aqueous solutions using polymer inclusion membranes (PIMs). PIMs consisted of cellulose triacetate (CTA) as a support; o-nitrophenyl pentyl ether (o-NPPE) as a plasticizer; and 1-octylimidazole (1), 1-octyl-2-methylimidazole (2), 1-octyl-4-methylimidazole (3), or 1-octyl-2,4-dimethylimidazole (4) as ion carriers. The membranes were characterized by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results show that Zn(II) and Cd(II) are effectively transported across PIMs, while Ni(II) transport is not effective. The rate of transport of metal ions across PIMs is determined by the diffusion rate of the M(II)–carrier complex across the membrane. The best result achieved for Zn(II) removal after 24 h was 95.5% for the ternary Zn(II)–Cd(II)–Ni(II) solution for PIM doped (4). For this membrane, the separation coefficients for Zn(II)/Cd(II), Zn(II)/Ni(II), and Cd(II)/Ni(II) were 2.8, 104.5, and 23.5, respectively. Additionally, the influence of basicity and structure of carrier molecules on transport kinetics was discussed.


2017 ◽  
Vol 68 (11) ◽  
pp. 2700-2703 ◽  
Author(s):  
Kamel Earar ◽  
Vasile Iulian Antoniac ◽  
Sorana Baciu ◽  
Simion Bran ◽  
Florin Onisor ◽  
...  

This study examined and compared surface of human dentine after acidic etching with hydrogen peroxide, phosphoric acid liquid and gel. Surface demineralization of dentin is necessary for a strong bond of adhesive at dental surface. Split human teeth were used. After application of mentioned substances at dentin level measures of the contact angle and surface morphology were employed. Surface morphology was analyzed with the help of scanning electron microscopy and atomic force microscopy. Liquid phosphoric acid yielded highest demineralization showing better hydrophobicity than the rest, thus having more contact surface. Surface roughness are less evident and formed surface micropores of 4 �m remained open after wash and air dry providing better adhesive canalicular penetration and subsequent bond.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.


2005 ◽  
Vol 106 ◽  
pp. 117-122 ◽  
Author(s):  
Izabela Szafraniak ◽  
Dietrich Hesse ◽  
Marin Alexe

Self-patterning presents an appealing alternative to lithography for the production of arrays of nanoscale ferroelectric capacitors for use in high density non-volatile memory devices. Recently a self-patterning method, based on the use of the instability of ultrathin films during hightemperature treatments, was used to fabricate nanosized ferroelectrics. This paper reports the use of the method for the preparation of PZT nanoislands on different single crystalline substrates - SrTiO3, MgO and LaAlO3. Moreover, a multi-step deposition procedure in order to control lateral the dimension of the crystals was introduced. The nanostructures obtained were studied by atomic force microscopy, scanning electron microscopy and X-ray diffraction.


2016 ◽  
Vol 857 ◽  
pp. 79-82
Author(s):  
Roslina Ismail ◽  
Fuaida Harun ◽  
Azman Jalar ◽  
Shahrum Abdullah

This work is a contribution towards the understanding of wire bond integrity and reliability in relation to their microstructural and mechanical properties in semiconductor packaging.The effect of surface roughness and hardness of leadframe on the bondability of Au wedge bond still requires detail analysis. Two type of leadframes namely leadframe A and leadframe B were chosen and scanning electron microscope (SEM) and optical microscope were used to inspect the surface morphology of leadframes and the quality of created Au wedge bond after wire bonding process. It was found that there were significant differences in the surface morphologies between these two leadframes. The atomic force microscopy (AFM) which was utilized to measure the average roughness, Ra of lead finger confirms that leadframe A has the highest Ra with value of 166.46 nm compared to that of leadframe B with value of 85.89 nm. While hardness value of different lead finger from the selected leadframe A and B obtained using Vicker microhardness tester are 180.9 VH and 154.2VH respectively.


2012 ◽  
Vol 711 ◽  
pp. 213-217 ◽  
Author(s):  
Anne Elisabeth Bazin ◽  
Frédéric Cayrel ◽  
Mohamed Lamhamdi ◽  
Arnaud Yvon ◽  
Jean Christophe Houdbert ◽  
...  

In this paper, we evaluated gallium nitride heteroepitaxially grown on sapphire (GaN/Sa) and grown on silicon (GaN/Si) faced to implantation doping. Si+ was implanted on low doped n-type epilayers in order to create a plateau around 1020at.cm-3. All the samples were capped with a silicon oxide and annealed between 1000°C and 1150°C. The surface quality was evaluated in terms of roughness, pit density and maximum pit diameter using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Finally, the dopant electrical activation was studied with Ti-Al contacts using the circular Transfert Length Method (c-TLM). This study shows that low Specific Contact Resistance (SCR) values of 8x10-5Ω.cm2 and 6x10-6Ω.cm2 are respectively obtained on GaN/Sa sample annealed at 1150°C-2min and on GaN/Si sample annealed at 1150°C-30s, proving that good ohmic contacts are obtained on both materials. Nevertheless, a compromise has to be done between the low SCR values obtained and the GaN surface degradation, observed by AFM and SEM after the different annealing treatments and which could affect the good behaviour of the GaN devices.


2021 ◽  
Author(s):  
Petar Stanić ◽  
◽  
Nataša Vukićević ◽  
Vesna Cvetković ◽  
Miroslav Pavlović ◽  
...  

Four 2-thiohydantoin derivatives were synthesized and their corrosion inhibition properties on mild steel (MS) in 0.5M HCl solution was evaluated using usual gravimetric and electrochemical methods (weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS). Morphology of the metal surface was characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The study has shown that these compounds provide good protection for mild steel against corrosion in the acidic medium.


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