Adsorption of Macroporous Phosphonic Acid Resin for Nickel

1Introduction Thesynthesischaracterizationandadsorptionproper tyofpolymericmaterialshavebeenresearchedinrecent years[110].Macroporousphosphonicacidresin[11](PAR)isanovelpolymericmaterialwhichcontainsafunctional groupof[PO(OH)2].Ithasalotofadvantagessuchas…     

Sorption Behavior and Mechanism of Indium（ Ⅲ ） onto Amino Methylene Phosphonic Acid Resin

The sorption behavior of amino methylene phosphonic acid resin (APAR) for In(III) was investigated. Experimental results show that In(III) adsorbed on APAR can be eluted with 2mol·L⁻¹ HCl. The apparent rate constant is k₂₉₈=1.50×10⁻⁵s⁻¹. The sorption behavior of APAR for In(III) obeys the Freundlich isotherm. The thermodynamic parameters of sorption, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of sorption (APAR) for In(III) are 24.1kJ·mol⁻¹, −35.1kJ·mol⁻¹ and 200J·mol⁻¹·K⁻¹, respectively. The coordination molar ratio of the functional group of APAR to In(III) is 2∶1. The sorption mechanism of APAR for In(III) was examined by IR spectrometry. XIONG Chun-hua: Born in 1959 0 This project was supported by Foundation of Zhejiang Provincial Education Bureau(No.20010677) and Lishui Science and Technology Bureau(No.2001012).     

Adsorption of Pb^2＋ on macroporous weak acid adsorbent resin from aqueous solutions： Batch and column studies

The adsorption properties of a novel macroporous weak acid resin (D152) for Pb²⁺ were investigated with chemical methods. The optimal adsorption condition of D152 resin for Pb²⁺ is at pH 6.00 in HAc-NaAc medium. The statically saturated adsorption capacity is 527 mg/g at 298 K. Pb²⁺ adsorbed on D152 resin can be eluted with 0.05 mol/L HCl quantitatively. The adsorption rate constants determined under various temperatures are k _{288 K}=2.22×10⁻⁵ s^t-1, k _{298 K}=2.51×10⁻⁵ s⁻¹, and k _{308 K}= 2.95×10⁻⁵ s⁻¹, respectively. The apparent activation energy, E _a is 10.5 kJ/mol, and the adsorption parameters of thermodynamics are ΔH ^Θ=13.3 kJ/mol, ΔS ^Θ=119 J/(mol·K), and ΔG ^Θ 298 K =−22.2 kJ/mol, respectively. The adsorption behavior of D152 resin for Pb²⁺ follows Langmuir model. Foundation item: Project(2008F70059) supported by the Scientific and Technological Research Planning of Zhejiang Province, China     

Water permeability parameters of dermal fibroblast employed in tissue engineering in subzero temperatures

In the construction of the tissue engineered dermal equivalent, the dermal fibroblast plays a crucial role[1]. While the fibroblasts need time to proliferate, synthesize, and se-crete extracellular matrix in the three-dimensional scaffold postseeding, a degradablescaffold commences disintegration over time. This may lead to an unusable product, if proper preservation does not conduct. Cryopreservation could solve this problem. The possibility of the long-term banking of cells and tissues would…     

Synthesis of 1,4-benzenedicarbonyl thiourea resins and their adsorption properties for Ag（I）

Several 1,4-benzenedicarbonyl thiourea resins (BTR) were synthesized through interfacial polymerization between 1,4-benzenedicarbonyl diisothiocyanate and polyamine. Their structures were confirmed by FT-IR. The adsorption properties (including the effect of adsorption time, pH, initial concentrations and temperature) of BTR-1, BTR-2 and BTR-3 for Ag(I) were investigated by batch tests. The results show that the adsorption equilibria of BTR-1, BTR-2, BTR-3 for Ag(I) are achieved after about 10 h. Their equilibrium adsorption capacities are 7.11, 6.75 and 6.23, respectively, and the adsorption process accords with G. E. Boyd equation and Langmuir adsorption isotherm as well. The adsorption capacities increase with the increase of pH (the highest uptake values are observed at pH being about 6–7). The thermodynamic parameters of BTR-1 were calculated. The results show that ΔH ^Θ; and ΔS ^Θ are 6 958.8 J/mol and 64.28 J/(mol·K), respectively, and ΔG ^Θ at 20, 30, 40 and 50 °C are −11.79, −12.52, −13.16 and −13.8 kJ/mol, respectively. The silver-loaded resins can be quantitatively eluted by a solution containing 6% thiourea in 1 mol/L HNO₃.     

Adsorption and desorption properties of D318 resin for Cr（Ⅵ）

The adsorption capability of D318 resin for Cr(VI) was investigated by chemistry analysis. Experimental results show that D318 resin has the best adsorption ability for Cr(VI) at pH=3.16 in HAc-NaAc medium. The statically saturated adsorption capacity of the resin is 265.4 mg/g. The thermodynamic adsorption parameters, enthalpy change ΔH and free energy change ΔG ₂₉₈ of the adsorption reaction are 4.81 and −5.16 kJ/mol, respectively. The apparent activation energy E _a is 22.4 kJ/mol. The adsorption behavior obeys the Freundlich isotherm. The molar coordination ratio of the functional group of resin to Cr(VI) is 3:2. Cr(VI) adsorbed on D318 resin can be eluted by 5%NaOH-5%NaCl quantitatively. Foundation item: Project (Y304121) supported by the Natural Science Foundation of Zhejiang Province, China     

Direct rapid determination of traces of sulfide in environment samples

An improved ethylene blue method for determination of sulfide is developed. It has been adapted to a direct determination of sulfide by both common spectrophotometric method and total differential spectrophotometric method. In common spectrophotometric method, the calibration curve is A=1.69ρ+0.006 and the correlation coefficient is 0.9994.The apparent molar absorptivity is 5.42×104 L*mol-1*cm-1 and calibration curve is liner when ρ is in the range of 0-0.9 mg*L-1. In total differential spectrophotometric method, the calibration curve is A=9.25ρ+0.004 and the correlation coefficient is 0.9996. The apparent molar absorptivity is 2.96×105 L*mol-1*cm-1and calibration curve is liner when ρ is in the range of 0-0.10 mg*L-1. The sensitivity of this method is increased significantly compared with the former ethylene blue method. The speed of reaction is also faster than the former one. The limit of detection is found to be 1.0 ng*mL-1 by both common spectrophotometric method and total differential spectrophotometric method. Ten replicate analyses of a sample solution containing 100 ng*mL-1sulfide give a relative standard deviation of 1.8%. The effects of various cations and anions on the determination of sulfide are studied and procedures for removal of interference is described. The method is used for the determination of sulfide in environment samples with satisfactory results.     

Experiments and reaction characteristics of liquid phase simultaneous removal of SO<Subscript>2</Subscript> and NO

Experiments of simultaneous removal of SO₂ and NO from simulated flue gas, using NaClO₂ solution as the absorbent, were carried out in a self-designed bubble reactor, and high simultaneous removal efficiencies of SO₂ and NO were obtained under the optimal experimental conditions. The mechanism of simultaneous removal based on NaClO₂ acid solutions was proposed by analyzing the removal products. Possibility and limitation of the desulfurization and denitrification using NaClO₂ acid solutions were calculated by thermodynamic methods. Experimental results of reaction kinetics for simultaneous desulfurization and denitrification indicated that the oxidation-absorption processes of SO₂ and NO were divided into two zones, namely the fast and slow reaction zones. In the slow reaction zones both were zero order reactions, and in the fast reaction zones, the reaction order, rate constant and activation energy of SO₂ reaction with absorbent were 1.4, 1.22 (mol·L⁻¹)^−0.4·s⁻¹ and 66.25 kJ·mol⁻¹, respectively, and 2, 3.15×10³ (mol·L⁻¹) ⁻¹·s⁻¹, and 42.50 kJ·mol⁻¹ for NO reaction, respectively. Supported by the National High-Tech Research and Development Program of China (“863” Project) (Grant No. 2007AA061803)     

Effect of Dy on structure and magnetic properties of DyxFe60.5?xPt39.5 Alloys

Effects of the content of Dy on structure and magnetic properties of Dy _x Fe_60.5−x Pt_39.5 alloys(x=0, 0.5, 1.0, 1.5) were investigated. The results of XRD analysis proved that the phase-transitional temperature of Dy _x Fe_60.5−x Pt_39.5 alloys from disordered face-centered-cubic structure to ordered face-centered-tetragonal cubic structure decreases with the increase of the content of Dy(x). Suitable content of Dy can improve the exchange coupling between soft magnetic phase and hard magnetic phase by refining grain size, while the remanence ratio and coercivity of the Fe_60.5Pt_39.5 alloy can be significantly improved by a small replacement of Fe by Dy, good magnetic properties were obtained in Dy_0.5Fe_60.0Pt_39.5 alloys.     

Simultaneous determination of adenine, uridine and adenosine in cordyceps sinensis and its substitutes by LC／ESI-MS

A simple, sensitive and reproducible high performance liquid chromatography-mass spectrometry coupled with electrospray ionization method for simultaneous separation and determination of adenine, adenosine and uridine was developed. The analytical column is a 2.0 mm× 150 mm Shimadzu VP-ODS column and volume fraction of the mobile phase is 86.5 %water, 12.0%methanol and 1.5%formic acid. 2-chloroadenosine was used as internal standard. Selective ion monitoring mode and selective ion monitoring ions at ratio of mass to electric charge of 136 for adenine, 268 for adenosine and 267 for uridine were chosen for quantitative analysis of the three active components. The results show that the regression equations and linear range are Y=0. 062X 0. 005 and 2.0 - 140.0μg · mL 1for adenine, Y=0. 049X 0. 004 and 4. 0 - 115.0 μg · mL-1 for uridine, Y=0. 154X 0. 014 and 1.0 - 125.0 μg · mL 1 for adenosine. The limits of detection are 0.6 μg · mL 1 for adenine, 1.0μg · mL-1 for uri dine and 0.2 μg · mL 1 for adenosine.The recoveries of the three constituents are from 96.6% to 103.2%.     

Adsorption performances and refrigeration application of adsorption working pair of CaCl<Subscript>2</Subscript>−NH<Subscript>3</Subscript>

The adsorption performance of CaCl₂−NH₃ is studied under the condition of different expansion spaces for adsorbent, and the relationships between adsorption performance of CaCl₂−NH₃ and the phenomena of swelling and agglomeration during adsorption are researched. It is found that the performance stability is related to the ratio of expansion space to the volume of adsorbent r _as, and the performance attenuation is serious in the case of large r _as. Severe adsorption hysteresis exists in the process of adsorption and desorption at the same evaporating and condensing temperatures, which is related to the stability constant of chemical reaction. This phenomenon cannot be explained by the theory of physical adsorption. Moderate agglomeration will be beneficial to the formation of ammoniate complex; the magnitude of expansion space will affect adsorption performance. Analysis shows that the activated energy needed in the process of adsorption for the sample with r _as. of 2∶1 is less than that for the sample with r _as of 3∶1. The refrigeration performance of CaCl₂−NH₃ is predicted from experiments. The cooling capacity of one adsorption cycle is about 945.4 kJ/kg for the adsorbent with an r _as of 2∶1 at the evaporating temperature of 0°C.     

Chemical reaction of in-situ processing of NiAl/Al2O3 composite by using thermite reaction

NiAl/Al₂O₃ composite were synthesized by thermite reaction of nickel oxide and aluminum powder mixtures. The phase, the microstructure of the composite, as well as the thermite reaction mechanism, were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) combined with differential scanning calorimetry (DSC). The experimental results show that the thermite reaction leads to the interpenetrating network structure of NiAl/Al₂O₃ at 1223K for 60 min and the chemical reaction apparent activation energy is E_ap=166.960±13.496 kJ·mol⁻¹ in the NiO/Al system. Funded by the Younger Teacher Foundation of High School of Anhui Province (No. 2003jq158)     

Critical driving force for martensitic transformation fcc (γ)→hcp(ε) in Fe-Mn-Si shape memory alloys

By the application of Chou's new geometry model and the available data from binary Fe-Mn, Fe-Si and Mn-Si systems, as well as SGTE DATA for lattice stability parameters of three elements from Dinsdale, the Gibbs free energy as a function of temperature of the fcc(γ) and hep(ε) phases in the Fe-Mn-Si system is reevaluated. The relationship between the Neel temperature of the γ phase and concentration of constituents in mole fraction, is fitted and verified by the experimental results. The critical driving force for the martensitic transformation fcc (γ)→ hep (ε), △ G_C~(γ→ε), defined as the free energy difference between γ and ε phases at M_s of various alloys can also be obtained with a known M_s. It is found that the driving force varies with the composition of alloys, e. g. △ G_C~(γ→ε) = - 100.99 J/mol in Fe-27.0Mn-6.0Si and △ G_C~(γ→ε) = - 122.11 J/mol in Fe-26.9Mn-3.37Si. The compositional dependence of critical driving force accorded with the expression formulated by Hsu of the     

Flow stress behavior of Cu13Zn alloy deformed at elevated temperature

Ｃｏｎｓｔｉｔｕｔｉｖｅｍｏｄｅｌｉｓａｍａｔｈｅｍａｔｉｃａｌｒｅｐｒｅｓｅｎｔａｔｉｏｎｏｆｔｈｅｄｅｆｏｒｍａｔｉｏｎｒｅｓｐｏｎｓｅｏｆａｍａｔｅｒｉａｌｔｏｅｘｔｅｒｎａｌｌｙａｐ ｐｌｉｅｄｌｏａｄｉｎｇ ,ｉｎｃｌｕｄｉｎｇｅｎｖｉｒｏｎｍｅｎｔａｌｆａｃｔｏｒｓ .Ｔｈｅｐｒｅ ｃｉｓｅｋｎｏｗｌｅｄｇｅｏｆｔｈｅｃｏｎｓｔｉｔｕｔｉｖｅｂｅｈａｖｉｏｒｏｆｔｈｅｍａｔｅｒｉａｌｉｓｔｈｅｆｏｕｎｄａｔｉｏｎｏｆｎｕｍｅｒｉｃａｌｓｉｍｕｌａｔｉｏｎｔｅｃｈｎｏｌｏｇｙｏｆｍａｔｅｒｉ…     

Synthesis and characterization of arsenate antimonic acid AAAc(1 : 1)

The AAAc(1 : 1) was synthesized in water by As₂O₃ and Sb₂O₃ with molar ratio of 1 : 1. AAAc(1 : 1) was characterized by Raman, IR, TG/DTG, DSC, XPS and XRD. The results show that there are four peaks to v _s of As-OH, As-O-Sb, Sb-OH and Sb-O-Sb in Raman spectra of AAAc(1 : 1) at 100 – 1 000 cm⁻¹. The solution of AAAc(1 : 1) was also titrated with KOH solution. The titration results show that AAAc(1 : 1) is a hexabasic acid with dissociation constants of k ₁=3.62 × 10⁻², k ₂=3.05 × 10⁻³, k ₃=6.43 × 10⁻⁶, k ₄ =9.78 × 10⁻⁸, k ₅=1.32 × 10⁻¹¹, k ₆=3.87 × 10⁻¹². AAAc(1 : 1) has a good solubility and stability in water, its solid obtained by free volatilizing water from its solution under air at ambient temperature is amorphous. Chemical and thermal analysis show that the composition of AAAc(1 : 1) is As₂O₅ · Sb₂O₅ · 8H₂O in air at 25 °C. AAAc(1 : 1) has the structure of AsO(OH)₂-OH-Sb(OH)₄-O-Sb(OH)₄-OH-AsO(OH)₂ or As(OH)₃-O-Sb(OH)₄-O-Sb(OH)₄-O-As(OH)₃ (isomerism) through experimental determination and geometry optimization. Foundation item: Project(50274075) supported by the National Natural Science Foundation of China     

Synthesis of modified D401 chelating resin and its adsorption properties for Pb^2＋

A novel chelating resin with sulfonic group was synthesized by chemical modification of D401 resin with sulphonation reaction and characterized by FT-IR spectrometry. The adsorption properties of the novel chelating resin for Pb²⁺ were studied by batch adsorption, and the adsorption process was analyzed from thermodynamics and kinetics aspects. The adsorption mechanism of Pb²⁺ on the modified D401 chelating resin was discussed by FT-IR spectrometry. Experimental results show that in the Pb²⁺ concentration range of 200–400 mg/L, the adsorption capacities of the modified D401 chelating resin for Pb²⁺ increase by 77%–129%, and Langmuir isothermal adsorption model is more suitable for the equilibrium adsorption data. Adsorption is an endothermic process that runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best pH value under adsorption condition is 4–5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the adsorption capacity remains stable after five consecutive adsorption-desorption cycles. The maximal static saturated adsorption capacity of the resin is 206 mg/g at 333 K in the Pb²⁺ concentration range of 200–400 mg/L. The modified D401 chelating resin is an efficient adsorbent for the removal of Pb²⁺ from its single-metal ion solution. Foundation item: Project(708049) supported by the Important Item Cultivation Foundation of Scientific Innovation Project of Colleges and Universities of China     

Synthesis of 3D ordered macroporous indium tin oxide using polymer colloidal crystal template

Three-dimensional (3D) ordered macroporous indium tin oxide (ITO) is pre- pared using a polymer colloidal crystal template that is formed by self-assembly of the monodisperse poly(methyl methacrylate) (PMMA) microspheres. The morphologies and BET surface area of the macroporous material is examined by scanning electron micro- scope, transmission electron microscopy and N2 adsorption/desorption. Results indicate that the macroporous material has highly ordered arrays of the uniform pores replicated from the PMMA colloidal crystal template when the polymer colloidal crystal template is removed by calcinations at 500℃. The pore diameter (about 450 nm) of macroporous ITO slightly shrank to the PMMA microspheres. The BET surface area and pore volume of the macroporous material are 389 m2·g-1 and 0.36 cm3·g-1, respectively. Moreover, the macroporous ITO, containing 5 mol% Sn and after annealing under vacuum, shows the minimum resistivity of ρ = 8.2×10-3 Ω· cm. The conductive mechanism of macroporous ITO is discussed, and it is believed that the oxygen vacancies are the major factor for excellent electrical properties.     

Measurement and Analysis of Density of Molten Ni-W Alloys

1IntroductionNi-based heat-resistant superalloys are widely usedto make critical components in gas-turbine engines,suchas bladeetc.But they are very hard and difficult to bemachined,the net-shape machining of these materials isveryimportant.Computer simul…     

The Thermal Decomposition Kinetics of Polysiloxane/Polymethylacrylate IPNs Materials

1Introduction Recently,anincreasingattentionhasbeenpaidtopolysiloxanebecausepolysiloxaneisthermallyresistantpolymerinhightemperaturewiththermalenduranceinoxidativeatmosphereupto300℃andmoreininertat mosphere.Thermoanalyticaltechniques,suchasthermo gravimetric(TG),differentialthermolgravimetric(DTG),anddifferentialscanningcalorimetry(DSC)havewidelybeenusedtocharacterizepolymericmaterials.Qingzeng Zhu[1]investigatedthethermaldecompositionofsilazanepolymerswiththermogravimetrymethodandindicat…     

Different Synthesis Methods for Ordered Mesoporous Silicas And Their Characteristics Comparison

1　IntroductionInorganicmesoporousmaterialshaveahighpotentialforapplicationsinthefieldsofcatalysis,adsorption ,sepa rationprocesses,biologymaterials,novelopticalmaterialsetc.Mesoporousmaterialshaverapidlyattractedresearchinterestsinthefieldofphysics,chemistryandmaterialssince 1 990s.Oneofthemostrepresentativemesoporousmaterialsismesoporoussilicapreparedbyusingalkylquaternaryammoniumcationicsurfactantsastemplate[1 3 ].Recently ,themesoporoussilicahasbecomeoneofthemostactivefieldsofhost guestass…