Chemistry Commons^™

The Effect Of Adsorbent Geometry And Surface Chemistry On Hplc Retention, Zhaoxia Liu

Seton Hall University Dissertations and Theses (ETDs)

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Patterning High Surface Area Silica With Lysozyme: Adsorption Kinetics, Fluorescence Quenching, And Protein Readsorption Studies To Evaluate The Templated Surface, Rachel M. Greer, Brittni A. Scruggs, R Alan May, Bert D. Chandler

Chemistry Faculty Research

A method was developed for using an inexpensive and widely available protein, hen egg white lysozyme, as a patterning agent for commercial high surface area silicas. The basic patterning methodology involved spontaneous adsorption of the protein from aqueous solution, alkylation of the uncovered surface with an alkylsiloxane, and protein desorption in a slightly alkaline solution of morpholine. Adsorption kinetic studies using Bradford assays assisted in determining protein deposition conditions. These studies were generally consistent with results on more planar silica surfaces and indicated that the protein quickly and strongly adsorbs along its long axis at low surface coverages. A modified …

Kinetic Evaluation Of Highly Active Supported Gold Catalysts Prepared From Monolayer-Protected Clusters: An Experimental Michaelis-Menten Approach For Determining The Oxygen Binding Constant During Co Oxidation Catalysis, Cormac G. Long, John D. Gilbertson, G. Vijayaraghavan, K. J. Stevenson, Christopher J. Pursell, Bert D. Chandler

Chemistry Faculty Research

Thiol monolayer-protected Au clusters (MPCs) were prepared using dendrimer templates, deposited onto a high-surface-area titania, and then the thiol stabilizers were removed under H2/N2. The resulting Au catalysts were characterized with transmission electron microscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy of adsorbed CO. The Au catalysts prepared via this route displayed minimal particle agglomeration during the deposition and activation steps. Structural data obtained from the physical characterization of the Au catalysts were comparable to features exhibited from a traditionally prepared standard Au catalyst obtained from the World Gold Council (WGC). A differential kinetic study of CO oxidation catalysis by the …

Open Circuit Potential Shifts Of Activated Carbon In Aqueous Solutions During Chemical And Adsorption Interactions, Mikhail M. Goldin, Vladimir A. Kolesnikov, Mogely Sh. Khubutiya, Alexander G. Volkov, Gary J. Blanchard, Anatoly K. Evseev, Mark M. Goldin

Faculty Publications and Presentations

Interaction of certain inorganic and organic compounds with activated carbon and the effect of such interaction on open circuit potential of activated carbon were studied. Open circuit potential shifts were observed for an overwhelming majority of the substances and brands of activated carbons investigated. Both negative and positive potential shifts were observed. It was shown that open circuit potential shifts for organic substances depend on degree of coverage of the activated carbon surface. Whereas adsorption of investigated organic compound on activated carbon led to positive potential shifts, desorption of adsorbates from the activated carbon surface led to potential shifts in …

Phosphorus Sorption In Relation To Soil Grain Size And Geochemical Composition In The Simiyu And Kagera River Basins, Tanzania, R. A. Tamatamah

Tanzania Journal of Science

The phosphorus sorption characteristics of eight surface soil samples representative of the land use and landscape in the Simiyu and Kagera River basins were determined using the Langmuir equation. The Langmuir P adsorption maximum (Cmax) ranged from 109 to 802 mg kg-1, while Langmuir coefficient (K) ranged from 59 to 736 mg L-1. Cmax and were positively correlated to clay content, aluminium (Al), and iron (Fe) and negatively correlated to calcium (Ca). By using stepwise regression, the combination of Al, Fe, clay and Ca predicted more than 94% of the variation in the P sorption capacity of soils samples from …

The Effect Of Silane Modification On The Adsorptive Properties Of Natural Pyrophyllite And Synthetic Titanium-Based Powders Prepared By The Sol-Gel Process, Şadi̇ye Şener, Murat Erdemoğlu, Meltem Asi̇ltürk, Hi̇kmet Sayilkan

Turkish Journal of Chemistry

Our aim was to improve the relatively poor adsorption characteristics of natural pyrophyllite and those of TiO_m and Ti(OR)_x(OH)_y(O)_z obtained from titanium tetraisopropoxide (TTIP) by the sol-gel process. For this purpose, the surfaces of the above-mentioned adsorbents were coated with a surface modifier by dipping them in 1% and 50% (w/w) solutions of N-(2-aminoethyl)-3- aminopropyltrimethoxysilane (DIAMO) in methanol. Realization of the coating processes was checked by FT-IR and SEM analyses. FT-IR analyses of the coated powders heat treated at 110 °C showed that condensation took place between OH groups of prehydrolyzed silane molecules and hydroxyl groups and/or oxygen atoms on …

Chemical And Biochemical Modification Of Surfaces For Control Of Wettability, Adsorption, And Drug Delivery, Susan C. D'Andrea

Seton Hall University Dissertations and Theses (ETDs)

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Preparations Of Spherical Polymeric Particles From Tanzanian Cashew Nut Shell Liquid By Suspension Polymerization, L L Mkayula, Y M M Makame, T H Matechi

Tanzania Journal of Science

Spherical Polymeric Particles (SPP) have been prepared from Tanzanian Cashew Nut Shell Liquid (CNSL) by suspension polymerization technique involving either step-growth or chain- growth polymerization mechanisms. The sizes of the SPP, which ranged from 0.1 to 2.0 mm were strongly influenced by the amounts of stabilizers in polymerization recipes used. The particles showed variable surface areas, indicative of the presence of pores in some of the preparations and the highest surface area recorded was about 260 m2g-1. The particles were found to exhibit Langmuir-type adsorption isotherms with saturation capacity of about 9.0 and 44.2 mg/g for Na+ and Ca2+, respectively. …

New Adsorbents From Ti(Opr^{N})_{4} By The Sol-Gel Process: Synthesis, Characterization And Application For Removing Some Heavy Metal Ions From Aqueous Solution, Funda Sayilkan, Hi̇kmet Sayilkan, Sema Erdemoğlu, Şadi̇ye Şener, Murat Akarsu

Turkish Journal of Chemistry

New adsorbents were synthesized by the sol-gel process from the product of a hydrolysis reaction and its coated form of titanium(IV)-n-propoxide for removing some heavy metal ions from aqueous solution. Titanium(IV)-n-propoxide was uncatalyst hydrolyzed with different amounts of water at room temperature and was found to react in a 1:1.6 ratio (mole of Ti:mole of H_{2}O). It was found that the condensation following the hydrolysis reaction was alcohol condensation. The hydrolysis-condensation product was characterized in detail by GC, Karl-Fischer coulometric titrator, NIR-spectroscopy, FT-IR spectroscopy, TG-DTA and elemental analysis. The hydrolysis-condensation product of titanium(IV)-n-propoxide was calcinated at 900 °C after drying …

Adsorption And Oxidation Of Phenol Electrode Processes, Bao-Cheng Wang, Yan-Ping Sun, Jin-Hua Zhu

Journal of Electrochemistry

The electrochemical behaviors of platinum electrode were studied by cyclic voltammetry in 1mol/L sulfuric acid solution and 1mol/L sulfuric acid solution contained phenol. The adsorption characteristics of phenol and the intermediat on electrode surface have been discussed. The reactive reversibility and oxidation mechanism of phenol on electrode process have been investigated.The potential of characteristic adsorption was suggested. The various products woud be formed when the electrode potential was greater than the one of characteristic adsorption.

Corrosion Inhibition Of Carbon Steel By An Amine- Fatty Acid In Acidic Solution, Joseph Buchweishaija

Tanzania Journal of Science

The corrosion inhibition of carbon steel in 3% de-aerated NaCl acidic solution with amine–fatty acid corrosion inhibitor, KI384, was investigated at different temperatures using potentiodynamic polarization technique. The Corrosion rate was calculated in the presence and absence of inhibitor. The inhibition increased with an increase in inhibitor concentration and decreased with rise in temperature. The maximum percentage inhibitor efficiency was obtained at 35 oC. The percentage inhibition up to 99% was registered at a concentration of 10 ppm of KI384. The inhibitor acts as a mixed type at lower temperature and predominantly anodic at high temperature. The interrelationship between the …

Synthesis, Characterization And Applications Of Sol-Gel Derived Zirconium Oxide Adsorbent Powder: Removal From Aqueous Solution Of Phenol And P-Chlorophenol, Murat Akarsu, Hi̇kmet Sayilkan, Şadi̇ye Şener, Funda Sayilkan, Ertuğrul Arpaç

Turkish Journal of Chemistry

Adsorbent powders were prepared from the uncatalysed hydrolysis-condensation reactions of different complexes that were synthesized by the reactions of Zr(OPr^{n})_{4} with different chelating ligands (such as allylacetic acid [AAH], vinylacetic acid [VAH] and citraconic acid [CAH]). The complex products were characterized by FT-IR, ^{1}H-NMR and ^{13}C-NMR spectra. The maximum combination ratios of AAH/Zr(OPr^{n})_{4}, VAH/Zr(OPr^{n})_{4} and CAH/Zr(OPr^{n})_{4} were 1.7, 0.9 and 1.3, respectively. The hydrolysis-condensation products of these complexes were calcinated at 900 °C and half of them were coated with 3-glycidyloxypropyltrimethoxysilane (GLYMO). The surface area and average pore diameter of the powders were estimated by the analysis of adsorption/desorption BET …

Electrochemical Behaviour Of Thymolphthalein, Mustafa Uçar, Necati̇ Menek

Turkish Journal of Chemistry

The polarographic and voltammetric behaviour of thymolphthalein in ethanol-water (1/5 v/v) was studied using various electrochemical techniques. The reduction of thymolphthalein on a mercury drop electrode was investigated. The adsorption effect on the electrode surface was observed. The rate constants for the electron transfer steps were determined by and without taking adsorption into occount using the Laviron technique and Nicholson technique respectively. The diffusion coefficients were calculated from the cyclic voltammetric data using the method developed by Garrido. Reversibility for the electrode reaction was investigated and a mechanism for the electrode reaction was proposed.

Adsorption Of Arsenate And Chromate From Waters On Hydrophobized Zeolitic Media, Eva Chmielewska

Turkish Journal of Chemistry

A laboratory setup was used to examine the uptake of chromate and arsenate from aqueous solutions by octadecylammonium acetate [ODA]-modified inland clinoptilolite. In trials, a natural variety of montmorillonite was compared to organic, i.e. surfactant loaded clinoptilolite. and some inorganically substituted (Ag, Pb) monoforms. The arrangement of the surface-attached ODA chains was the important factor for differences in the adsorption states of the guest species (oxyanions). A novel nano-structure inorganic-organic composite was prepared and was characterized by SEM, thermogravimetry, HR TEM, UV-VIS diffuse reflectance and powder XRD spectral analytical methods. Finally, the adsorption isotherms of the studied system were expressed. …

Mechanistic Studies Of Carbon Steel Corrosion Inhibition By Cashew Nut Shell Liquid, J Y N Philip, J Buchweishaija, L L Mkayula

Tanzania Journal of Science

The inhibition mechanism of the Cashew Nut Shell Liquid (CNSL) on SAE 1008 carbon steel corrosion in CO 2  saturated 3% NaCl solutions has been studied by weight loss, UV/VIS and electrochemical techniques. The phenoxide, R-Ar-O- ions from the CNSL inhibitor were found to be responsible for the reduction of the corrosion rate of the carbon steel. Also, it was observed that the surface charge of the carbon steel electrodes was positive with respect to the solutions containing CNSL inhibitor. It is likely that the mechanism of the CNSL inhibitor adsorption involved the electrostatic attraction between the positively charged metal …

Preparation And Characterization Of Activated Carbons From Rice Husks And Shells Of Palm Fruits, Jeg Mdoe, Ll Mkayula

Tanzania Journal of Science

Activated carbons from palm fruit shells (PFS) and rice husks (RH) were prepared using physical and chemical activation processes, respectively. The influence of activation time and temperature (in the case of PFS) and impregnation ratio and carbonization temperature (in the case of RH) on the properties of the resultant carbons were studied. In the case of PFS carbons, there were an increase in adsorption capacity and surface areas with increase in activation time and temperature. The surface area ranged between 292 and 642 m2g-1 at temperature range of between 1000 and 1200 K. In the case of RH carbons, surface …

The Influence Of Gold Substrate Topography On The Voltammetry Of Cytochrome C Adsorbed On Carboxylic Acid Terminated Self-Assembled Monolayers, Michael C. Leopold, Edmond F. Bowden

Chemistry Faculty Publications

Interfacial investigations of a protein monolayer electrochemical system, equine cytochrome c (cyt c) adsorbed to carboxylic acid terminated self-assembled monolayer (COOH SAM) modified gold electrodes, were performed. Electrochemical, spectroscopic, and scanning probe microscopy techniques were utilized to explore the influence of gold topography in the cyt c/COOH SAM/gold system. COOH SAMs were prepared from 14-mercaptotetradecanoic acid and 11-mercaptoundecanoic acid on a variety of substrates including evaporated, bulk, single crystal, and epitaxially grown gold on mica. These substrates encompassed a wide range of surface roughness. As the topography of the gold became smoother, SAMs exhibited an increased ability to …

Solvent, Temperature And Concentration Effects On The Adsorption Of Poly(N-Butyl Methacrylate) On Alumina From Solutions, Nursel Pekel, Olgun Güven

Turkish Journal of Chemistry

Adsorption of poly(n-butyl methacrylate) (PnBMA) on alumina from solution was studied by UV and FT-IR Photoacoustic Spectroscopy techniques. The effects of the solvent, temperature, concentration, and molecular weight of the polymer on adsorption were investigated. Three solvents, cyclohexane, carbon tetrachloride and benzene, were employed. The adsorption was dependent on molecular weight and much more polymer was adsorbed in cyclohexane than in other solvents on the alumina surface. A decrease in adsorption was observed with increasing temperature. The results are in conformity with Langmuir's isotherm. The differences observed in Langmuir parameters were explained by polymer-polymer, polymer-solvent, polymer-adsorbent, and solvent-adsorbent interactions.

Electrochemical Behavior Of Benzo[C]Cinnoline And Its Bromo Derivatives, Ni̇lgün Seçken, M. Levent Aksu, Ali̇ Osman Solak, Emi̇ne Kiliç

Turkish Journal of Chemistry

The electrochemical behavior of benzo[c]cinnoline and some of its bromo derivatives was studied. Two discrete 2-electron reduction waves in acidic and only one wave in basic media in ethyl alcohol-BR buffer system (l:5 v/v) were observed. A mechanism for the electrode reaction is proposed. Diffusion coefficients, formal potentials for and the derivatives, the number of electrons transferred were determined by using sampled current polarography, cyclic voltammetry, chronoamperometry, chronocoulometry and constant potential coulometry. Adsorption of the molecules on the surface of the mercury drop was analyzed and this phenomena was exploited to calculate the formal potentials and the diffusion coefficients of …

The Partition/Adsorption Model For The Description Of The Retention Mechanism In Reversed Phase Liquid Chromatography, Tarun S. Patel

Seton Hall University Dissertations and Theses (ETDs)

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Investigation Of The Microporous And Mesoporous Structures Of The Reşadiye (Tokat/Turkey) Bentonite And Its Fractions, Müşerref Önal, Yüksel Sarikaya, Tülay Alemdaroğlu

Turkish Journal of Chemistry

It was determined by X-ray diffraction that, besides containing clay minerals such as montmorillonite and illite, the original bentonite contained also clinoptilolite, opal-C, quartz, calcite and dolomite. The original bentonite was separated into four fractions by decantation and precipitation from its aqueous suspension. The adsorption and desorption of nitrogen on the original bentonite and its fractions at 77 K were investigated. The specific surface areas of the samples were determined according to the methods of Brunauer-Emmett-Teller, de Boer-Lippens, and Harkins-Jura by using the adsorption data. The mesopore size distribution curves were plotted by using the desorption data. The specific micropore …

Electrochemical Behavior Of Riboflavin On Glassy Carbon Electrode, Hong Li, Lin-Cai Jiang, Liang-Nian Ji

Journal of Electrochemistry

The electrochemical behavior of riboflavin(RF) on glassy carbon has been investigated by using potential sweep, rotating ring-disc electrode and the measurement of differential capacitance. It is shown that a single well-behaved oxidation-reduction wave corresponding to a reversible two-electrons reaction apears in medium of pH<6, and the adsorption of RFH₂ formed by electro-reduction is weak and hence its solubility is good. In medium of pH>6, there are two separating but overlapping partly oxidation-reduction waves corresponding to two-step one-electron reaction. The adsorptions of RFH and RFH₂ produced by reduction reactions in medium of 6

Some Aspects Of The Adsorption Of A Lennard-Jones Gas On A Rough Surface, Douglas Henderson, Pawel Bryk, Stefan Sokolowski

Faculty Publications

We study the adsorption, including wetting, of a Lennard-Jones gas on a rough surface consisting of rough layer on a smooth substrate with which the gas interacts via a 9-3 potential. The rough layer is two molecular diameters thick and consists of a disordered quenched matrix of hard spheres. As well as interacting with the other matrix spheres by the hard-sphere potential, the matrix molecules interact with the gas molecules by the hard-sphere potential. Hence, on average, the degree to which the gas molecules can approach the substrate depends only on the density of the matrix layer. The density of …

Adsorption Of Copper And Cadmium Lons By Activated Carbon From Rice Hulls, Murat Teker, Mustafa İmamoğlu, Ömer Saltabaş

Turkish Journal of Chemistry

The removal of copper (II) and cadmium (II) ions from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH), was investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time were determined to be 5-8, 0.5 g ACRH/25 mL solution an 60 minutes respctively for the adsorption of Cu (II) ions and 5-8, 1.5 g ACRH/25 mL solution and 60 minutes for the adsorption of Cd (II) ions. From the initial concentrations, the constants for the Freundlich and Langmuir isotherm were calculated …

Investigation Of Adsorption Isotherms Of Myristic, Palmitic And Stearic Acids On Rice Hull Ash, Hüseyi̇n Topallar, Yüksel Bayrak

Turkish Journal of Chemistry

The adsorption of myristic, palmitic and stearic acids on rice hull ash from isooctane as solvent was studied and conformed to a Langmuir isotherm. Monolayer coverage was determined to be 40.08, 38.43 and 37.27 mg/g, respectively. The free energy of adsorption, \Delta G°_{ads}, for the adsorption was determined to be -6,25, -6.32 and -6.39 kcal mol^{-1} for the adsorbates, respectively. The equilibrium parameter indicated that rice hull ash is a good adsorbent for myristic, palmitic and stearic acids examined.

The Adsorption-Desorption Behaviors Of Β Phenylaminopropiophenone On Iron In Sulphuric Acid Solution, Xianzhang Bu, Dihua Wang, Jinyun Zou, Fuxing Gan

Journal of Electrochemistry

The adsorption-desorption behaviors of β-phenylaminopropiophenone (PAP) on iron in 0.5 mol·L^-1 H₂SO₄ solution with or without halide ions (Cl^-, I^-) were investigated by potentiostatic polarization measurement. The results show that the adsorption of PAP on iron surface follows Flory-Huggins isotherm, the adsorption free energy parameter (f) is positive in H₂SO₄ solution; In the presence of 0.1 mol·L^-1 Cl^-1, when C_PAP ≤ 2×10^-5 mol·L^-1, f＞0. A desorption phenomenon was observed at more positive potential region in anodic polarization curves. Furthermore, the anodic desorption …

Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian

Journal of Electrochemistry

Good quality potential-dependent surface Raman spectra of pyridine were obtained for the first time from a series of transition metals, e. g., Fe, Co, Ni, Ru, Rh, Pd and Pt, which were electrodeposited on non-SERS-active substrates. The influences of the applied potential and the nature of metal on the adsorption behaviors were discussed briefly. This result illustrates that Raman spectroscopy is becoming a more general and powerful tool to study various electrochemical interfaces.

Atomic And Molecular-Perspectives In Electrochemical Interfaces, Zhaowu Tian

Journal of Electrochemistry

The following recent studies on the atomic and molecular-perspectives at electrochemical interfaces using Raman, IR, STM and quantum chemical methed by electrochemistry group in Xiamen University are briefly reviewed. 1.Orientation, charge transfer and bonding of adsorbed molecules. 2. Adsorption effect, electrode potential effect and adatom effect on the electron populations and strength of intramolec ular bonds of the adsorbed molecules. 3. Detailed classification into various types (e. g., competitive, chemically inductive, physical inductive etc.) of coadsorption on electrodes according to the above-mentioned effects.  4. Single crystal face structure effect and adatom effect on the kinetics and the mechanisms of electrocatalytic …

Surface Structure Of √3x√3r 30 Cl/Ni(111) Determined Using Low-Temperature Angle-Resolved-Photoemission Extended Fine Structure, Li-Qiong Wang, Z. Hussain, Z. Q. Huang, A. E. Schach Von Wittenau, Dennis W. Lindle, D. A. Shirley

Chemistry and Biochemistry Faculty Research

A surface structural study of the √3 × √3 R30° Cl/Ni(111) adsorbate system was made using low-temperature angle-resolved photoemission extended fine structure. The experiments were performed along two emission directions, [111] and [110], and at two temperatures, 120 and 300 K. The multiple-scattering spherical-wave analysis determined that the Cl atom adsorbs in the fcc threefold hollow site, 1.837(8) Å above the first nickel layer, with a Cl-Ni bond length of 2.332(6) Å, and an approximate 5% contraction between the first and the second nickel layers (the errors in parentheses are statistical standard deviations only).

A Study Of The Removal Of Pesticides From Water, James David Whitehouse

KWRRI Research Reports

The purpose of this study was to investigate some of the properties of pesticides as they exist in water, and to determine the effectiveness of several water treatment processes in the removal of pesticides from water. Among the pesticides investigated were malathion, DDT, aldrin, dieldrin, captan, benzene hexachloride (BHC), 2,4-D, and 2,4,5-T. The water treatment processes included aeration, chemical coagulation, adsorption on activated carbons and clays, and foam separation.

The removal of pesticides from water by aeration was found to be significant. Dieldrin was removed almost 100 percent, while aldrin, DDT, and BHC were removed to a lesser extent. 2, …