scholarly journals Immobilization of Residual Basic Dyes onto Polyamide Ion-Exchanger Materials

2005 ◽  
Vol 23 (7) ◽  
pp. 555-572 ◽  
Author(s):  
Mohamed Hassen V Baouab ◽  
Mohamed Khalfaoui ◽  
Aghleb Bartegi ◽  
Robert Gauthier
Keyword(s):  
Experimental Data ◽  
Methacrylic Acid ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Visible Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nylon 6,6 ◽  
Basic Dyes ◽  
Langmuir And Freundlich Models

This paper reports the preparation of methacrylic acid-grafted nylon (MAA—nylon) by treating nylon-6,6 fibres with methacrylic acid (MAA) and the use of this modified polyamide as an ion-exchanger for the immobilization of pollutant basic dyes. The grafting of MAA onto nylon-6,6 was demonstrated both by weight uptake and atomic force microscopy. The exchange capacity of MAA—nylon was evaluated by potentiometric titration of the acidic groups. Five MAA—nylon fibres with different degrees of grafting (20–80%) were tested for the adsorption of two basic dyes, viz. Basic Blue 3 and Basic Red 24. Such adsorption was monitored by visible spectroscopy. The adsorption capacity was found to depend on the degree of grafting and on the temperature. The experimental data were fitted using the Langmuir and Freundlich models. However, an improved fit could be obtained by using the Jossens model.

scholarly journals Atomic force microscopy study of nanoindentation deformation and indentation size effect in MgO crystals

1999 ◽  
Vol 14 (10) ◽  
pp. 3973-3982 ◽  
Author(s):  
K. Sangwal ◽  
P. Gorostiza ◽  
J. Servat ◽  
F. Sanz
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Atomic Force Microscopy ◽  
Size Effect ◽  
Deformation Zone ◽  
Indentation Size Effect ◽  
Indentation Size ◽  
Depth Of Penetration ◽  
Force Microscopy ◽  
Atomic Force

The dependences of various nanoindentation parameters, such as depth of penetration d, indentation diameter a, deformation zone radius R, and height h of hills piled up around indents, on applied load were investigated for the initial (unrecovered) stage of indentation of the (100) cleavage faces of MgO crystals by square pyramidal Si tips for loads up to 10 μN using atomic force microscopy. The experimental data are analyzed using theories of elastic and plastic deformation. The results revealed that (i) a, R, and h linearly increase with d; (ii) the development of indentation size and deformation zone and the formation of hills are two different processes; (iii) the load dependence of nanohardness shows the normal indentation size effect (i.e., the hardness increases with a decrease in load); and (iv) there is an absence of plastic deformation involving the formation of slip lines around the indentations. It is found that Johnson's cavity model of elastic–plastic boundary satisfactorily explains the experimental data. The formation of hills around indentations is also consistent with a new model (i.e., indentation crater model) based on the concept of piling up of material of indentation cavity as hills.

scholarly journals Pengambilan ion cadmium (II) dari air limbah simulasi menggunakan fly ash aktif: studi kesetimbangan

2018 ◽  
Vol 7 (2) ◽  
pp. 798
Author(s):  
I Made Bendiyasa ◽  
D Setiawan ◽  
R. Octaviany
Keyword(s):  
Experimental Data ◽  
Fly Ash ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Langmuir Model ◽  
Initial Concentration ◽  
Fixed Concentration ◽  
Experimental Rig ◽  
Langmuir And Freundlich Models ◽  
Good Agreement

The experimental study of equilibrium of Cadmium (II) adsorbed with fly ash has been performed. The experimental rig was consisted of a 0.5 L three neck flask, a stirrer, a condenser and a thermometer. The rig was immersed in a water bath that was used to control the experimental temperature. The three neck flask was filled with 0.3 L Cadmium solution of a fixed concentration and then 0.3 g of flay ash was put into the flask. Chemical composition of fly ash are as follows (weight %): SiO2 = 54,23; Al2O3 = 25,38; H2O = 2,5; MgO = 1,O; Ca0 = 4,63; Na20 = 0,32; K20 = 0,60; Mn0 = 0,014; Fe2O3 = 6,01; TiO2 = 0,007; P2O5 = 0,042 and loss of ignition (LOI) is 5,26. Cation exchange capacity is 990 meq/kg fly ash. Each run was conducted for 2 hours, and at the end of each experiment Cadmium (II) was analyzed with Atomic Absorbtion Spectrophotometer (AAS). Variables studied were temperature ranging from 303 to 323 K and initial concentration of Cadmium (II) from 7 to 10 mg Cadmium (II) L-1. Experimental data were evaluated with both Langmuir and Freundlich models. It is found that the experimental data is in a good agreement with Langmuir model. Relationships between K for Langmuir and Freundlich and temperature are, respectively, KLangmuir = 2,841066e(-35401,01/RT) and KFreundlich = 4, 75104e(-34403,20/RT) Keywords: fly ash, Langmuir, Freundlich, Cadmium, equilibrium Abstrak Pengambilan Cd(II) dari air limbah simulasi diteliti dengan menggunakan fly ash sebagai adsorben. Tujuan utama penelitian ini adalah mempelajari kesetimbangan adsorpsi Cd(II) dengan fly ash. Disamping itu juga bertujuan untuk mengetahui kapasitas maksimum adsorpsi fly ash. Setiap percobaan dilakukan dalam suatu reaktor batch yang suhunya dipertahankan tetap. Reaktor yang digunakan adalah labu leher tiga dengan volum 0, 5 L yang dilengkapi dengan pengaduk merkuri, pendingin balik, dan termometer. Fly ash dengan berat 0,3 gram dimasukkan ke dalam reaktor yang telah diisi dengan suatu larutan Cadmium dengan volume 0,3 L dan konsentrasi tertentu. Komposisi kimia fly ash adalah (% berat): %): SiO2 = 54,23; Al2O3 = 25,38; H2O = 2,5; MgO = 1,O; Ca0 = 4,63; Na20 = 0,32; K20 = 0,60; Mn0 = 0,014; Fe2O3 = 6,01; TiO2 = 0,007; P2O5 = 0,042 dan berat hilang = 5,26. Fly ash yang dipakai mempunyai nilai kapasitas pertukaran kation (KPK) yang nilainya sama dengan 990 meq/kg fly ash. Setiap percobaan dilakukan selama dua jam, dan kemudian konsentrasi Cd(II) di dalam larutan  dianalisis kadar Cd(II)-nya menggunakan Atomic Absorbtion Spectrophotometer (AAS). Variabel yang dipelajari adalah suhu (T) dan konsentrasi awal (Co) larutan. Kisaran suhu yang diteliti adalah 303 sampai 323 K dan konsentrasi awal (Co) antara 7 sampai 10 mg Cd(11) L-1. Data percobaan dievaluasi dengan model Langmuir dan Freundlich.  Hasil penelitian menunjukkan bahwa adsorpsi Cd(II) dengan fly ash lebih sesuai dengan model Langmuir. Hubungan K untuk Langmuir dan Freundlrich dengan suhu berturut adaIah KLangmuir = 2,841066e(-35401,01/RT) and KFreundlich = 4, 75104e(-34403,20/RT)Kata kunci: fly ash, Langmuir, Freundlich, Cadmium, kesetimbangan

scholarly journals Локальное анодное окисление слоев графена на SiC

2018 ◽  
Vol 44 (9) ◽  
pp. 34
Author(s):  
П.А. Алексеев ◽  
Б.Р. Бородин ◽  
М.С. Дунаевский ◽  
А.Н. Смирнов ◽  
В.Ю. Давыдов ◽  
...  
Keyword(s):  
Experimental Data ◽  
Raman Spectroscopy ◽  
Anodic Oxidation ◽  
Scanning Velocity ◽  
Force Microscopy ◽  
Atomic Force ◽  
Local Anodic Oxidation ◽  
Probe Voltage ◽  
20 Nm ◽  
Oxidation Parameters

AbstractA method of local anodic oxidation has been used to obtain graphene-oxide regions on SiC. The change of the surface properties was confirmed by atomic-force microscopy and Raman spectroscopy. Experimental data were obtained on the conductivity, potential, and topography of the oxidized regions. It was shown that the oxidation leads to a rise in the surface potential. A relationship was found between oxidation parameters, such as the scanning velocity and the probe voltage. The method of local anodic oxidation was used to obtain by lithography an ~20-nm-wide nanoribbon and an ~10-nm-wide nanoconstriction.

Electromigration of Silicon Adatoms on Silicon (111) Surface

2011 ◽  
Vol 6 (2) ◽  
pp. 65-76
Author(s):  
Ekaterina E. Rodyakina ◽  
Sergey S. Kosolobov ◽  
Aleksandr V. Latyshev
Keyword(s):  
Electron Microscopy ◽  
Experimental Data ◽  
Effective Charge ◽  
Ex Situ ◽  
Equilibrium Conditions ◽  
Force Microscopy ◽  
Homoepitaxial Growth ◽  
Atomic Force ◽  
Reflection Electron Microscopy

Existence of adatom gradient concentration on surface between step bunches was shown under sublimation, homoepitaxial growth and near equilibrium conditions on silicon (111) surface at above 900 ºС by means of in situ ultrahigh vacuum reflection electron microscopy and ex situ atomic force microscopy. It is experimentally confirmed that adatom have negative (at 1 100 ºС) and positive (at 1 300 ºС) effective charge. We found out the sign of adatom effective charge independent on the supersaturation volume on the surface. On the hasement of experimental data we evaluated the effective charge of adatom at 1 280ºС; this quantity is placed between 0,07 ± 0,01 and 0,17 ± 0,02 of electron unit

Direct visualization of the real time swelling and collapse of a poly(methacrylic acid) brush using atomic force microscopy

Soft Matter ◽  
2009 ◽  
Vol 5 (2) ◽  
pp. 296-299 ◽  
Author(s):  
Andrew J. Parnell ◽  
Simon J. Martin ◽  
Richard A. L. Jones ◽  
C. Vasilev ◽  
Colin J. Crook ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Real Time ◽  
Methacrylic Acid ◽  
Direct Visualization ◽  
The Real ◽  
Force Microscopy ◽  
Atomic Force

Growth Aspects of Photochemically Synthesized Silver Triangular Nanoplates

2007 ◽  
Vol 7 (2) ◽  
pp. 618-625 ◽  
Author(s):  
Túlio C. R. Rocha ◽  
Daniela Zanchet
Keyword(s):  
Aspect Ratio ◽  
Photochemical Synthesis ◽  
Visible Spectroscopy ◽  
Quantitative Characterization ◽  
Detailed Characterization ◽  
Incident Wavelength ◽  
Force Microscopy ◽  
Electron Microscopies ◽  
Atomic Force

Aspects of the growth mechanism of silver triangular nanoplates by photochemical synthesis were addressed by detailed characterization using ultraviolet-visible spectroscopy, electron microscopies, and atomic force microscopy. The quantitative characterization of their size and thickness during the reaction showed that both increase with time as well as the aspect ratio. Samples irradiated by different wavelengths showed that the size of the nanoplates can be controlled by the incident wavelength and it is responsible for the increase of the aspect ratio, but the thickness seems to be determined by the conditions of the initial seeds. It was also found that irradiation with wavelength out of resonance with the surface plasmon of the initial seeds leads to a slower kinetics. The results suggested that rational exploration of the synthesis parameter such as the type of the initial seeds in combination with the wavelength irradiation may lead to a broader type of particles already obtained by this method.

Rheology behavior of lubricants and its effect on the quality surface of aluminum and copper cold-drawn wires

2012 ◽  
Vol 1373 ◽  
Author(s):  
R. Cortes Rodríguez ◽  
R. Garza García ◽  
J. Pérez Patiño ◽  
E. Reyes Melo ◽  
E. López Cuellar
Keyword(s):  
Experimental Data ◽  
Lower Energy ◽  
Manufacturing Plant ◽  
Additional Energy ◽  
Energy Process ◽  
Force Microscopy ◽  
Low Viscosity ◽  
Atomic Force ◽  
Quality Surface

AbstractThe roll of lubricants in the cold-drawn process is very important to obtain a good quality on the surface of aluminum and copper wires. The viscosity of a lubricant is closely related to its ability to reduce friction. When the viscosity of a lubricant is too low, the lubricated component will have inadequate protection and will therefore be subject to excessive wear. When the viscosity of the lubricant is too high, the lubricated component will expend additional energy to complete its task. In this work, the rheology behavior of traditional lubricants for the cold drawn of Al and Cu is determined from experimental data of viscosity Vs shear rate. To evaluate the efficiency of each lubricant, the roughness surface of each wire is measured by Atomic Force Microscopy (AFM). In this way a minimum of roughness in wires corresponds to the viscosity required for each cold-drawn process. It is known that different lubricants are used for the cold drawn of Al and Cu. In this work, a new lubricant developed with the aim to be used in both process is characterized by FTIR, rheometer analysis and AFM. Results have indicated that, this new lubricant with a low viscosity that promotes a lower energy process, also decreases the roughness of Al and Cu wires compared with conventional lubricants, i.e.it has an important influence in the quality of the wires surface. This means that this new lubricant could be used during the process of both metals without making important changes, which means low operations costs and flexibility for the manufacturing plant.

scholarly journals Study of Langmuir monolayers and Langmuir-Schaefer films based on symmetrical meso-aryl-substituted porphyrin derivative

2021 ◽  
Vol 2086 (1) ◽  
pp. 012195
Author(s):  
V N Mironyuk ◽  
A J K Al-Alwani ◽  
N N Begletsova ◽  
M V Gavrikov ◽  
A S Kolesnikova ◽  
...  
Keyword(s):  
Experimental Data ◽  
Langmuir Monolayers ◽  
Specific Area ◽  
Compression Modulus ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Solid Substrates ◽  
Compression Isotherms ◽  
Transfer Pressure

Abstract This paper presents the results of a study of meso-aryl-substituted porphyrin Langmuir monolayers by the method of compression isotherms. Experimental data were used to plot the dependences of the compression modulus (C−1) on the specific area. Monolayers at specific surface pressure were transferred to solid substrates and investigated. The monolayers were transferred to the surface of monocrystalline silicon at surface pressures of 8, 25, and 60 mN/m and examined them by atomic force microscopy (AFM) in a semi-contact mode. It was found that with an increase in the transfer pressure, the coarsening of molecular aggregates occurs. The smallest roughness is observed for a porphyrin film formed and transferred at a pressure of 8 mN/m.

Development and Optimization of Biometal Nanoparticles by Using Mathematical Methodology: A Microbial Approach

2015 ◽  
Vol 30 ◽  
pp. 106-115 ◽  
Author(s):  
Soheila Honary ◽  
Hamed Barabadi ◽  
Pouneh Ebrahimi ◽  
Farzaneh Naghibi ◽  
Ahad Alizadeh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Atomic Force Microscopy ◽  
Oxide Nanoparticles ◽  
Visible Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Uv Visible ◽  
Scanning Electron

This study aimed to biosynthesize and optimize the process of iron oxide nanoparticles producing by Penicilliumwaksmanii isolated from soil by employing mathematical methodology. The synthesized nanoparticles were formed with fairly well-defined dimensions with good monodispersity determined by SEM (Scanning Electron Microscopy), AFM (Atomic Force Microscopy), DLS (Dynamic Light Scattering), UV-Visible spectroscopy, zeta potential, polydispersity index (PDI) and correlogram of nanoparticles. The effects of different factors such as pH, temperature and concentration of FeCl3 on the particle size were investigated by Box-Behnken experimental design. The R2 value was calculated to be 0.9992 indicating the accuracy and ability of the polynomial model.

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