Syntheses and characterization of polystyrene‐supported 2,5‐dimercapto‐1,3,4‐thiodiazole and its sorption behavior for Pd(II), Pt(IV), and Au(III)

A type of chelating resin crosslinking polystyrene‐supported 2,5‐dimercapto‐1,3,4‐thiodiazole (also called bismuththiol I, BMT), containing sulfur and nitrogen atoms, was prepared. The structure of PS‐BMT was confirmed by FTIR, elemental analysis, and X‐ray photoelectron spectroscopy (XPS). Adsorption of Pd(II), Pt(IV), and Au(III) was investigated. The capacity of PS‐BMT to adsorb Pd(II) and Pt(IV) was 0.190 and 0.033 mmol/g, respectively. The adsorption dynamics of Pd(II) showed that adsorption was controlled by liquid film diffusion and that the apparent activation energy, E_a, was 32.67 kJ/mol. The Langmuir model was better than the Freundlich model in describing the isothermal process of Pd(II), and the ΔG, ΔH, and ΔS values calculated were ?0.33 kJ/mol, 26.29 kJ/mol, and 87.95 J mol^?1 K^?1, respectively. The mechanisms of adsorption of Pd(II), Pt(IV), and Au(III) were confirmed by XPS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 631–637, 2006     

Syntheses and adsorption properties for Hg2+ of chelating resin of crosslinked polystyrene‐supported 2,5‐dimercapto‐1,3,4‐thiodiazole

A novel chelating resin with functional group containing S and N atoms was prepared using chloromethylated polystyrene and 2,5‐dimercapto‐1,3,4‐thiodiazole (also called bismuththiol I, BMT) as materials. Its structure was characterized by infrared spectra and elementary analysis. The results showed that the content of the functional group was 2.07 mmol BMT g^?1 resin, 47% of which were in the form of monosubstitution (PS‐BMT‐1) and 53% in the form of double substitution (PS‐BMT‐2). The adsorption for mercury ion was investigated. The adsorption dynamics showed that the adsorption was controlled by liquid film diffusion. Increasing the temperature was beneficial to adsorption. The Langmuir model was much better than the Freundlich model to describe the isothermal process. The adsorption activation energy (E_a), ΔG, ΔH, and ΔS values calculated were 18.56 kJ·mol^?1, ‐5.99 kJ·mol^?1, 16.38 kJ·mol^?1, and 37.36, J·mol^?1·K^?1, respectively. The chelating resin could be easily regenerated by 2% thiourea in 0.1 mol·L^?1 HCl with higher effectiveness. Five adsorption–desorption cycles demonstrated that this resin was suitable for repeated use without considerable change in adsorption capacity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1646–1652, 2004     

Synthesis,characterization, and properties for Hg2+ of new chelating resin containing sulfoxide and 3‐aminopyridine

A new chelating resin (PVESO‐AP) containing sulfoxide and 3‐aminopyridine (AP) was synthesized by using chloromethylated polystyrene‐co‐divinylbenzene (PS‐Cl) as material. Its structure was characterized by infrared spectra and elemental analysis. The adsorption capacities of the newly formed resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, Cd²⁺, and Ni²⁺ were determined at pH 2 and 5. In addition, the adsorption selective coefficients for Hg²⁺ in several binary mixture systems were investigated by batch experiment method. The results showed that this resin had high adsorption selectivity for Hg²⁺. The adsorption kinetics and isothermal of PVESO‐AP for Hg²⁺ at different temperatures were also investigated. The adsorption kinetics showed that the apparent activation energy E_a was 13.71 kJ/mol. The results also showed that the Langmuir model was better than the Frundlich model to describe the isothermal process of PVESO‐AP resin for Hg²⁺. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Studies on two‐dimensional coordination polymer cadmium phosphate and its high efficient adsorption of Pb(II) ions from aqueous solutions

The two‐dimensional coordination polymer cadmium phosphate with the morphology of rectangle layers was prepared by solid‐state template reaction at room temperature, and was characterized by XRD, FTIR, and TEM techniques. The as‐synthesized sample is a layered cadmium phosphate material, in which the structure is poly (CdPO₄^?) anion framework with ammonium ions and water species residing in the space between the layers, and cadmium ions are coordinated by the phosphate oxygen atoms. This article also presents the adsorption of Pb(II) ions from aqueous solution on the as‐synthesized coordination polymer cadmium phosphate, and the results showed that this inorganic polymer adsorbent had good adsorption capacity. It could reach to the saturation adsorption capacity within an hour, and its excellent adsorption capacity for Pb(II) was 5.50 mmol/g when the initial solution concentration was 1.68 × 10³ μg/mL at T = 278K. Moreover, the adsorption kinetics and adsorption isotherms were studied, it revealed that the adsorption kinetics can be modeled by pseudo second‐order rate equation wonderfully. The apparent activation energy (E_a), ΔG, ΔH, and ΔS were 3.16 kJ mol^?1, ?13.97 kJ mol^?1, ?11.84 kJ mol^?1, and 7.66 J mol^?1 K^?1, respectively. And it was found that Langmuir equation could well interpret the adsorption of the as‐synthesized coordination polymer cadmium phosphate for Pb(II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents

To investigate the effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents, macroporous polystyrene (PS) resin and PS‐based adsorbents with different hydrogen‐bond acceptor atoms (PS CH₂( OCH₂CH₂)_n OCH₃, n = 0, 1, 2, and 3, denoted as PS‐EG₀, PS‐EG₁, PS‐EG₂, and PS‐EG₃) were prepared. The phenol adsorption strength order on these adsorbents was PS/PS‐EG₀ < PS‐EG₁ < PS‐EG₂ < PS‐EG₃, indicating that the adsorption on PS and PS‐EG₀ was driven by hydrophobic and π–π interactions, and the adsorption on PS‐EG₁, PS‐EG₂, and PS‐EG₃ was driven by a hydrogen bond in addition to hydrophobic and π–π interactions. PS‐EG₂ may adsorb a second phenol molecule on each binding site and PS‐EG₃ may adsorb second and third ones. The adsorption strength of resorcinol increased in the order of PS, PS‐EG₁, and PS‐EG₂, indicating that the adsorption was driven by 0, 1, and 2 hydrogen bonds in addition to hydrophobic and π–π interactions. Similarly, the adsorption of phloroglucinol on PS, PS‐EG₁, PS‐EG₂, and PS‐EG₃ was driven by 0, 1, 2, and 3 hydrogen bonds in addition to hydrophobic and π–π interactions because the adsorption strength increased in this order. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4652–4658, 2006     

Green and efficient synthesis of an adsorbent fiber by preirradiation‐induced grafting of PDMAEMA and its Au(III) adsorption and reduction performance

N ,N ‐Dimethylamino ethyl methacrylate (DMAEMA) is covalently bonded on a commercial polyethylene‐coated polypropylene skin‐core structure fiber (PE/PP) in aqueous and MeOH/H₂O solutions by a one‐step green reaction using radiation‐induced graft polymerization. The effects of the absorbed dose and solvent system on grafting yield are investigated, while the chemical and physical properties of the functionalized fiber are also evaluated. The fiber with a D_g of 51.6% exhibited good adsorption capacity of Au(III) ions over a large range of concentrations (from 10 to 2.5 g L^?1) in both batch and flow‐through adsorption tests. The highest capacity of Au was 949.3 mg g^?1. After elution, the adsorbents can be reused without any further regeneration for at least five adsorption‐desorption cycles. Additionally, the fibers show high selectivity for Au(III). The distribution coefficient of Au(III) is 10⁴ to 10⁵ times higher than that for Cu(II), Fe(III), Ni(II), and Pb(II) even at 100 times lower Au(III) concentration compared to the co‐existing metal ion concentration. This study provides an effective and novel approach for gold recovery from aqueous solutions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44955.     

Synthesis and adsorption properties of macroporous cross‐linked polystyrene that contains an immobilizing 2,5‐dimercapto‐1,3,4‐thiodiazole with tetraethylene glycol spacers

A novel chelating resin macroporous cross‐linked polystyrene immobilizing 2,5‐dimercapto‐1,3,4‐thiodiazole via a hydrophilic tetraethylene glycol spacer (PS‐TEG‐BMT) is synthesized and the structure is characterized by means of Fourier transform infrared spectroscopy (FTIR), energy dispersive X‐ray microanalysis (EDX), and elementary analysis. Its adsorption capacity for several metal ions such as Hg²⁺, Ag⁺, Ni²⁺, Pb²⁺, Cd²⁺, Fe³⁺, Bi³⁺, Zn²⁺, and Cu²⁺ are investigated. The initial experimental result shows that this resin has higher adsorption selectivity for Hg²⁺ and Ni²⁺ than for the other metal ions and the introduction of hydrophilic TEG spacer is beneficial to increase adsorption capacities. The result also shows that the Langmuir model is better than the Freundlich model to describe the isothermal process of PS‐TEG‐BME resin for Hg²⁺. Five adsorption‐desorption cycles demonstrate that this resin are suitable for reuse without considerable change in adsorption capacity. POLYM. ENG. SCI., 45:1515–1521, 2005. © 2005 Society of Plastics Engineers     

Thermodynamics,kinetics, and isotherms studies for gold(III) adsorption using silica functionalized by diethylenetriaminemethylenephosphonic acid

A novel hybrid material silica gel chemically modified by diethylenetriaminemethylenephosphonic acid GH-D-P has been developed and characterized. The results of the adsorption thermodynamics and kinetics of the as-synthesized GH-D-P for Au(III) showed that this high efficient inorganic–organic hybrid adsorbent had good adsorption capacity for Au(III), and the best interpretation for the experimental data was given by the Langmuir isotherm equation, the maximum adsorption capacity for Au(III) is 357.14 mg/g at 35 °C. Moreover, the study indicated the adsorption kinetics of GH-D-P could be modeled by the pseudo-second-order rate equation wonderfully, and the adsorption thermodynamic parameters ΔG, ΔH and ΔS were −20.43 kJ mol⁻¹, 9.17 kJ mol⁻¹, and 96.24 J K⁻¹ mol⁻¹, respectively. Therefore, the high adsorption capacity make this hybrid material have significant potential for Au(III) uptake from aqueous solutions using adsorption method.     

Preparation and characterization of selective phenyl thiosemicarbazide modified Au(III) ion‐imprinted cellulosic cotton fibers

In this study, a novel selective Au(III) chelating surface ion imprinted fibers based on phenyl thiosemicarbazide modified natural cotton (Au‐C‐PTS) has been synthesized, and applied for selective removal of Au(III) from aqueous solutions. Batch adsorption experiments were performed with various parameters, such as contact time, pH, initial Au(III) concentration, and temperature. The kinetic studies revealed that the adsorption process could be described by pseudo‐second‐order kinetic model, while the adsorption data correlated well with the Langmuir and Freundlich models. The maximum adsorption capacities calculated from the Langmuir equation are 140 ± 1 mg g^?1 and 72 ± 1 mg g^?1 at pH 5 for both Au‐C‐PTS and NI‐C‐PTS, respectively. The estimated thermodynamic parameters (Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy change (ΔS°)) indicated the spontaneity and exothermic nature of the adsorption process. Furthermore, the selectivity study revealed that the ion imprinted fibers was highly selective to Au(III) compared with Cu(II), Cd(II), Hg(II), and Fe(III). The adsorbent was successfully regenerated with a 0.1M HNO₃ solution. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40769.     

Preparation,characterization, and adsorption properties for metal ions of a novel chelating resin containing sulfoxide and diethylene glycol

A novel chelating resin containing sulfoxide and diethylene glycol, poly{4‐vinylbenzyl‐[2‐2‐(hydroxyethyl)ethoxyl]sulfoxide} (PVESO) was synthesized using chloromethylated polystyrene (PS‐Cl) as material. Its structure was characterized by elemental analysis, infrared spectra, and scanning electron microscopy (SEM). The adsorption capacities of the resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, and Pb²⁺ at various pH values were determined. The maximum adsorption capacities for Hg²⁺ and Ag⁺ were 1.56 and 0.75 mmol g^?1 respectively. The resin had high selectivity for Hg²⁺ and Ag⁺ over the pH range 1.0–7.0. The adsorption capacities for Hg²⁺ and Ag⁺ under competitive condition were also determined by batch experiment method. In addition, the adsorption kinetics of the resin towards Hg²⁺ at different temperatures was also investigated. The results showed that the adsorption rate was governed by film diffusion at 20°C and 25°C, by particle diffusion at 30°C and 35°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6054–6059, 2006     

Comparison of the metrics between the CIELAB and the DIN99 uniform color spaces using dental resin composite material values

The sizes for the perceptible or acceptable color difference measured with instruments vary by factors such as instrument, material, and color‐difference formula. To compensate for disagreement of the CIELAB color difference (ΔE^*_ab) with the human observer, the CIEDE2000 formula was developed. However, since this formula has no uniform color space (UCS), DIN99 UCS may be an alternative UCS at present. The purpose of this study was to determine the correlation between the CIELAB UCS and DIN99 UCS using dental resin composites. Changes and correlations in color coordinates (CIE L*,a*, and b* versus L₉₉, a₉₉, and b₉₉ from DIN99) and color differences (ΔE^*_ab and ΔE₉₉) of dental resin composites after polymerization and thermocycling were determined. After transformation into DIN99 formula, the a value (red–green parameter) shifted to higher values, and the span of distribution was maintained after transformation. However, the span of distribution of b values (yellow–blue parameter) was reduced. Although color differences with the two formulas were correlated after polymerization and thermocycling (r = 0.77 and 0.68, respectively), the color coordinates and color differences with DIN99 were significantly different from those with CIELAB. New UCS (DIN99) was different from the present CIELAB UCS with respect to color coordinates (a and b) and color difference. Adaptation of a more observer‐response relevant uniform color space should be considered after visual confirmation with dental esthetic materials. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 168–173, 2006     

Silica gel‐based adsorbents prepared via homogeneous and heterogeneous routes: adsorption properties and recycling as heterogeneous catalysts

Silica gel‐based adsorbents were prepared via homogeneous and heterogeneous routes using two silane coupling reagents, 3‐glycidoxypropyltrimethoxysilane and γ ‐chloropropyltrimethoxysilane. Characterization results showed that amino contents of the adsorbents prepared via the homogeneous route were higher than those of the adsorbents prepared via the heterogeneous route for both silane coupling reagents. The adsorption capabilities of the resulting four types of adsorbents for Hg(II), Cu(II), Au(III), Ni(II), Pb(II) and Ag(I) ions were compared. Good adsorption capability for Au(III) was observed for the new adsorbents and the maximum static saturated adsorption capacities for Au(III) could reach 0.67 mmol g^?1. Due to the formation of Au(0) particles in the adsorption process, which hampered the reusability of the spent adsorbents, alternative recycling of the spent adsorbents after Au(III) adsorption was sought. The spent adsorbents were treated with NaBH₄ and used as catalysts in the reduction of 4‐nitrophenol to 4‐aminophenol. After three catalytic cycles at 298 K, the k values indicated minimal decrease of catalytic activity. © 2017 Society of Chemical Industry     

Simultaneous adsorptive removal of methylene blue and copper ions from aqueous solution by ferrocene‐modified cation exchange resin

Resin was modified with ferrocene (Fc) to enhance removal of Methylene Blue (MB) and Cu²⁺ from simulated wastewater. The FTIR, N₂‐BET, and X‐ray fluorescence analysis confirmed that Fc was successfully grafted onto the surface of resin. The adsorption capacity of Fc modified cation exchange resin (FMCER) was calculated to be 392.16 mg/g Cu²⁺ and 10.01 mg/g MB. Both processes were spontaneous and exothermic, best described by Langmuir equation. Pseudo‐first‐order kinetic model satisfied the adsorption of MB, while the intraparticle‐diffusion model fitted the kinetics of Cu²⁺ adsorption best. The result revealed a multilayer adsorption of Cu²⁺ on FMCER, and the kinetics maybe controlled by intraparticle diffusion, film diffusion, and competition force. The adsorption of MB and Cu²⁺ on FMCER were physicosorptive, with activation energies of 2.09 and 1.27 kJ/mol. pH 2–7 and 4–5 are optimum for the removal of MB and Cu²⁺, and pH 4 is optimal for the simultaneous removal of MB and Cu²⁺. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41029.     

Corrosion Inhibition Efficiency,Electrochemical and Quantum Chemical Studies of Some New Nonionic Surfactants for Carbon Steel in Acidic Media

In this work, three types of nonionic surfactant as corrosion inhibitors were synthesized. The chemical structure of the prepared inhibitors was confirmed using FT‐IR and ¹H‐NMR spectroscopy. The surface tension and thermodynamic properties of these inhibitors were investigated. The corrosion inhibition efficiency of these surfactants was investigated on a carbon steel surface in 1 M HCl solution by weight loss and electrochemical measurements. Untreated and treated steel surfaces were characterized by scanning electron microscopy. Results show that the inhibition efficiency of the prepared inhibitors increases with increasing the ethylene oxide units. Also, the potentiodynamic polarization curves indicated that the investigated inhibitors behave as a mixed type inhibitor. Adsorption of these surfactants on the carbon steel surface was found to obey Langmuir's adsorption isotherm. The computed quantum chemical properties viz., electron affinity (EA), highest occupied molecular orbital (E_HOMO), the lowest unoccupied molecular orbital (E_LUMO), energy gap ΔE = E_HOMO ? E_LUMO, dipole moment (μ), polarizability and total energy (E_T) show good correlation with experimental inhibition efficiency.     

Isothermal and nonisothermal melt‐crystallization kinetics of syndiotactic polystyrene

Analyses of the isothermal and nonisothermal melt kinetics for syndiotactic polystyrene have been performed with differential scanning calorimetry, and several kinetic analyses have been used to describe the crystallization process. The regime II→III transition, at a crystallization temperature of 239°, is found. The values of the nucleation parameter K_g for regimes II and III are estimated. The lateral‐surface free energy, σ = 3.24 erg cm^?2, the fold‐surface free energy, σ_e = 52.3 ± 4.2 erg cm^?2, and the average work of chain folding, q = 4.49 ± 0.38 kcal/mol, are determined with the (040) plane assumed to be the growth plane. The observed crystallization characteristics of syndiotactic polystyrene are compared with those of isotactic polystyrene. The activation energies of isothermal and nonisothermal melt crystallization are determined to be ΔE = ?830.7 kJ/mol and ΔE = ?315.9 kJ/mol, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2528–2538, 2002     

Preparation of redox fibers containing hydroxy‐alkyl amino groups and their adsorptive properties toward Au(III)

Three kinds of redox fibers (fibers II, III, and IV) are prepared by amination of the reactive chloromethylated poly(vinyl acetate) grafting polystyrene‐divinylbenzene fiber (fiber I) with diethanolamine, ethanolamine, or triethanolamine. The N‐content of the fibers is 2.26, 2.71, and 1.86 mmol g⁻¹, respectively. Results of static adsorption experiments show that the adsorption amount of fibers II, III, and IV toward Au(III) reaches 550 mg g⁻¹, 620 mg g⁻¹, and 409 mg g⁻¹, respectively, between pH 2.0 and pH 3.0. Some adsorbed Au(III) can be reduced to Au(0). The reduction percentage of Au(III) adsorbed by fiber II increases with rising pH value of the solution and can be as high as 87% at pH 5.0. The amount of Au(III) adsorbed by fiber II increases with solution temperature, but decreases with ionic strength of the solution. The adsorption amount of fibers II and III toward Au(III) is less in ethanol or in acetacetate medium than in water. Kinetic adsorption data indicates that 50 min is needed for fiber II to adsorb half of its saturate adsorption amount of Au(III). It was proved by elemental analysis, infrared spectroscopy, nuclear magnetic resonance, and electron spectroscopy for chemical analysis determinations that the carbon atoms connecting with the hydroxy groups near the nitrogen atoms were easily oxidized into carbonyl ones during redox adsorption reaction of fibers II, III, and IV with Au(III). Some grains of gold adsorbed on fiber II were discovered under scanning electron microscopy. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 47–54, 1999     

New method for evaluation of kinetic parameters and mechanism of degradation from pyrolysis–GC studies: Thermal degradation of polydimethylsiloxanes

Thermal degradation of polydimethylsiloxane (PDMS) polymers having hydroxyl (PS) and vinyl (PS‐V) terminals was studied by pyrolysis‐gas chromatography (PGC) in the temperature range from 550 to 950°C. The degradation products were primarily cyclic oligomers ranging from trimer (D₃) to cyclomer D₁₁ and minor amounts of linear products and methane. The product composition varied significantly with pyrolysis temperature and extent of degradation. A new method was developed to derive a mass loss‐temperature curve (pyrothermogram, PTG) and to determine the kinetic parameters of decomposition (k, n, and E_a) from sequential pyrolysis studies. It was shown that isothermal rate constants can be derived from repeated pyrolysis data. Good agreement between the rate constants derived from the two methods validates the methodology adopted. This was further confirmed from thermogravimetric studies. The E_a values for the decomposition of PS and PS‐V derived from sequential pyrolysis were 40 ± 2 and 46 ± 2 kcal mol⁻¹, respectively. Various mechanisms for the degradation of PDMS were reviewed and discussed in relation to the PGC results. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 441–450, 1999     

Ability of iron(III)‐loaded carboxylated polyacrylamide‐grafted sawdust to remove phosphate ions from aqueous solution and fertilizer industry wastewater: Adsorption kinetics and isotherm studies

Iron(III)‐loaded carboxylated polyacrylamide‐grafted sawdust was investigated as an adsorbent for the removal of phosphate from water and wastewater. The carboxylated polyacrylamide‐grafted sawdust was prepared by graft copolymerization of acrylamide and N,N′‐methylenebisacrylamide onto sawdust in the presence of an initiator, potassium peroxydisulfate. Iron(III) was strongly attached to the carboxylic acid moiety of the adsorbent. The adsorbent material exhibits a very high adsorption potential for phosphate ions. The coordinated unsaturated sites of the iron(III) complex of polymerized sawdust were considered to be the adsorption sites for phosphate ions, the predominating species being H₂PO ions. Maximum removal of 97.6 and 90.3% with 2 g L^?1 of the adsorbent was observed at pH 2.5 for an initial phosphate concentration of 100 and 250 μmol L^?1, respectively. The adsorption process follows second‐order kinetics. Adsorption rate constants as a function of concentration and temperature and kinetic parameters, such as ΔG^±, ΔH^±, and ΔS^±, were calculated to predict the nature of adsorption. The L‐type adsorption isotherm obtained in the sorbent indicated a favorable process and fitted the Langmuir equation model well. The adsorption capacity calculated by the Langmuir adsorption isotherm gave 3.03 × 10^?4 mol g^?1 of phosphate removal at 30°C and pH 2.5. The isosteric heat of adsorption was also determined at various surface loadings of the adsorbent. The adsorption efficiency toward phosphate removal was tested using industrial wastewater. Different reagents were tested for extracting phosphate ions from the spent adsorbent. About 98.2% of phosphate can be recovered from the adsorbent using 0.1M NaOH. Alkali regeneration was tried for several cycles with a view to recover the adsorbed phosphate and also to restore the adsorbent to its original state. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2541–2553, 2002     

Equilibrium of benzidine inclusion adsorption on cyclodextrin copolymer

Insoluble β‐cyclodextrin (β‐CD) copolymer was prepared by reacting β‐CD with hexamethylene diisocyanate, and its inclusion adsorption behavior was investigated. The physical and chemical properties of CD copolymer were characterized by SEM, FTIR, DSC, TGA, XRD, and BET N₂ adsorption. The effects that shaking time and temperature exerted on the inclusion adsorption of benzidine on CD copolymer have been studied at relative low initial benzidine concentration. The procedure of the inclusion adsorption could be described by the Freundlich equation, and the thermodynamic constants ΔH^θ, ΔS^θ and ΔG^θ were obtained simultaneously. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Adsorption of bismuth(III) by bayberry tannin immobilized on collagen fiber

The adsorption behavior of collagen fiber‐immobilized bayberry tannin towards Bi(III) at acidic pH values was investigated. The adsorption capacity of the adsorbent towards Bi(III) was 0.348 mmol g^?1 at 303 K, and increased with the rise in temperature. The adsorption isotherms of Bi(III) were in the shape of so‐called type II isotherms and could be described by an empirical equation, ln q_e = k + (1/n)C_e, which implies that chemical adsorption is predominant at lower concentrations of Bi(III) and that physical adsorption is involved at higher concentrations. The adsorption kinetics of Bi(III) on the immobilized bayberry tannin could be well described by the pseudo‐second‐order rate model, and the adsorption capacities calculated by the model were almost the same as those determined by actual measurements. The adsorbent could be regenerated by using 0.02 mol dm^?3 ethylenediaminetetraacetic acid (EDTA) solution after adsorption of Bi(III). The adsorption selectivity of the immobilized bayberry tannin towards Bi(III) in a Cu(II)–Bi(III) binary solution in acidic medium was remarkable. Therefore, it is strongly suggested that the immobilized bayberry tannin could be applied to the removal of Bi(III) from crude Cu(II) samples under proper conditions. Copyright © 2006 Society of Chemical Industry