Synthesis of Zeolite ZSM-2 Using Zeolite NaX as Seeds

Introduction Oxygen and nitrogen have been produced tradition-ally by cryogenic distillation of air. Methods for the non-cryogenic separation based on selective adsorption have been developed and commercialized since the 1970s and have led to a cost-effective process for this important separation.1 Low-silica zeolites are important materials for producing oxygen by selective adsorption of nitrogen. In 19891990, a new generation of lith-ium-based adsorbents was developed.2,3 Highly lithium exc…     

Investigation of Quantitative Relationship between Adsorbed Amount of Solute and Solvent Concentration at Relatively High Solute Con－centration by Frontal Analysis in RPLC

In previous paper a new adsorption isotherm which relates the amount of solute absorbed to the solvent concentration is pro-posed and simplified, and it only can be used at lower solute concentration. In this article the scope of the new adsorption isotherm is extended and the expressions with three and four parameters are obtained. The equations with multi-parameters are valid when the adsorbed mounts are larger and show non-linear logarithmic relationships. Tests with a homologue of are-matic alcohols by frontal analysis in reversed phase liquid chro-matography demonstrate that the experimental results fit those equations well. In addition, the predicted values by the multi-parameters were found to fit the experimental values well also. The parameters have physical meaning only for the two-param-eter equation for the aromatic alcohols.     

Facile Synthesis and Adsorption Properties of Phosphonated Cellulose Beads for Selective Removal of Low-density Lipoprotein

Hyperlipemia, which induced by the abnormally elevated level of lipids in plasma such as cholesterol and triglyceride (TG), now has been widely recognized as a major risk factor of coronary heart disease1. Low-density lipoprotein (LDL) particles are the m…     

Crystal Growth Kinetics of Nanocrystalline ZnS under Surface Adsorption

The crystal growth mechanism,kinetics,and microstructure development play a fundamental role in tailoring the materials with controllable size and morphology. In this study,by introducing the strong surface adsorption of the concentrated NaOH,two-stage crystal growth kinetics of ZnS nanoparticles was observed. In the first stage,the primary particles grow into a size over a hundred times of the original volume and the growth is controlled by the crystal-lographically specific oriented attachment. The first stage data were fitted by the "multistep OA kinetic model" built based on the molecular collision and reaction. In the second stage,following the dispersal of nanoparticles,an abrupt transition from asymptotic to parabola growth kinetics occurs,which can be fitted by a standard Ostwald ripening volume diffusion model. The presence of surface adsorption causes the two-stage growth kinetics and permits an almost exclusive OA-based growth to dominate in the first stage.     

Experimental and Theoretical Study of the Effect of Moisture on Methane Adsorption and Desorption by Activated Carbon at 273.5 K

Adsorption and desorption of methane by activated carbon (AC) at constant temperature and at various pressures were investigated. The effect of moisture was also studied. A volumetric method was used, up to 40 bar, at a temperature of 273.5 K. Results of a dry AC sample were compared with those obtained from a moist sample and two different ACs with different physical and surface properties were used. As expected, the results showed that the existence of moisture, trapped in the AC pores, could lead to a decrease in the amount of methane adsorbed and a decrease in the amount of methane delivered during desorption. To model the experimental results, a large variety of adsorption isotherms were used. The regressed parameters for the adsorption isotherms were obtained using the experimental data generated in the present study. The accuracy of the results obtained from the different adsorption isotherms was favorably compared.     

Synthesis and Properties of Novel Hemicyanine Dye-β-Cyclodextrin

A series of novel hemicyanine dye-β-cyclodextrin compounds： mono-6-deoxy-β-cyclodextrin-6-[p-（p-substituted styryl）pyridium] p-totylfulfonates were synthesized by the condensation of mono-6-deoxy-β- cyclodextrin-6-（p-methyl pyridinium） p-toluenesulfonate with （un）substituted benzaldehydes. Their structures were established by 1^H NMR, IR, UV-Vis and elemental analysis. The absorption and fluorescence properties of the novel compounds were measured in solution and the photostability of a selected hemicyanine dye-β-cyclodextrin compound was also investigated.     

Properties and Characterization of Modified HZSM—5 Zeolites

Physicochemical and catalytic properties of phosphorus and boron modified HZSM-5 zeolites treated with 100% steam at 673K were investigated.The acidity and distribution of acidic sites were studied by infrared spectroscopy using pyridine as probe molecule and temperature programmed desortion (TPD) of ammonia.The structure of the samples was characterized by XRD,and the textural properties of the catalysts were determined by nitrogen isothermal adsorption-desorption measurements and scanning electron microscopy(SEM).The XRD results show that the modified samples have no novel crystalline phase,indicating a high dispersion of phosphorus and boron species.After treatment,the microporous volume and surface area of the samples markedly decrease,implying the bolockage of the channel.The nitrogen adsorption-desorption measurements suggest that the isothermal type of all samples is a combination of isothermal type Ⅰ and Ⅳ，and all hysteresis loops resemble the H4-type in the IUPAC classification.The total acidity of the modified samples,determined by pyrldine adsorption IR and TPD of ammonia,decreases in contrast to that of the parent HZSM-5.The conversion of n-heptane over P and B steammodified HZSM-5 is higher than that of P and B-modified HZSM-5 zeolites but lower than that of the parent HZSM-5.     

STUDY ON THE ADSORPTION OF OXIDATION OF CROSSLINKED β—CYCLODEXTRIN AND ITS CXOMPOSITE ADSORBENT WITH DIALYTIC MEMBRANE

An urea adsorbent with an aldo structure was obtained by the oxidation of a crosslinked β-cyclodextrin polymer.The highest urea adsorption capacity reached 56.7mg/g in 0.05Maqueous phosphate buffer 37℃ and pH=7.4,and decrease to 4.8mg/g in in aqueous human serum albumin.The composite adsorbent was prepared by the oxidation of a crosslinked β-cyclodextrin and dialytic membrane.It was found that the composite adsorbent has a higher urea adsorption selectivity and capacity compared to that of the oxidation of a crosslinked β-cyclodextrin adsorbent when urea is in aqueous human serum albumin.     

Study of preparation and adsorption properties of imidacloprid mesoporous surface molecularly imprinted polymerEI北大核心CSCD

Imidacloprid mesoporous surface molecularly imprinted polymer (MIP) was rapidly synthesized by one[1]step method, with imidacloprid as template molecule, methacrylic acid (MAA) as functional monomer, azodiisobutyronitrile (AIBN) as initiator and ethylene glycol dimethacrylate (EGDMA) as crosslinker. The characterization of MIP was completed by SEM, TEM, FT-IR, and nitrogen adsorption-desorption isotherms. The adsorption conditions were optimized. At the imidacloprid concentration of 100 µg/mL, MIP reached adsorption saturation and the adsorption time was shorter than that of the corresponding non-imprinted polymer (NIP), with the saturated adsorption value of 3.628 mg/g, and the imprinting factor of 1.27, indicating that the mesoporous structure and surface imprinting improved the mass transfer rate of imidacloprid in the adsorption process, so as to improving the adsorption capacity. In addition, under the same conditions, the adsorption capacity of MIP for imidacloprid was higher than acetamiprid, thiacloprid and thiamethoxam, indicating that MIP had better specific recognition ability. The imidacloprid mesoporous surface MIP can be prepared simply and rapidly, which may be a potential material in the field of sample pretreatment and rapid detection. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Synthesis and properties of polyfluorene copolymers bearing thiophene and porphyrin

To search for more wider absorption and higher charge carriers mobilities materials of polymer solar cell, a series of soluble alternating polyfluorene copolymers were synthesized by palladium-catalyzed Suzuki coupling reaction. Their structures were determined by 1H NMR, IR and UV-vis. And their UV-vis absorption spectra indicated that they had strong absorption over 600 nm spectral range and nearly cover 400-700 nm visible region. The band gaps of copolymers calculated according to cyclic voltammetry （CV） were between 1.96 and 2.03 eV. Polymer：TiO2 bulk-heterojunction films were made from mixtures of polymer and titanium isopropoxide, a precursor for TiO2, via hydrolysis in air overnight. The photoluminescence at 380-800 nm of the blend film of PT-TPP20 （5 mg/mL）：Ti（OC3H7）4 （80 μL/mL） （20% volume fraction） was significantly quenched in the 50% Ti（OC3H7）4 blend film, indicating that rapid and efficient separation of photoinduced electron-hole pairs.     

Determination of trace amounts of morphine in human plasma by anodic adsorptive stripping differential pulse voltammetry

New adsorptive anodic differential pulse stripping voltammetry method for the direct determination of morphine at trace levels in human plasma of addicts is proposed.The procedure involves an adsorptive accumulation of morphine on a HMDE,followed by oxidation of adsorbed morphine by voltammetry scan using differential pulse modulation.The optimum conditions for the analysis of morphine are pH 10.5,Eacc of -100 mV（vs.Ag/AgCl）,and tacc of 120 s.The peak current is proportional to the concentration of morphine,and a Linear calibration graph is obtained at 0.01-3.10μg mL^-1.A relative standard deviation of 1.06%（n=5）was obtained,and the limit of detection was 3 ng mL^-1.The capabiLity of the method for the analysis of real samples was evaluated by the determination of morphine in spiked human plasma and addicts human plasma with satisfactory results.     

Synthesis of Diethyl Oxalate by a Coupling-Regeneration Reaction of Carbon Monoxide

This article describes a process for the synthesis of diethyl oxalate by a coupling reaction of carbon monoxide, catalyzed by palladium in the presence of ethyl nitrite. The kinetics and mechanism of the coupling and regeneration reaction are also discussed. This paper presents the results of a scale-up test of the catalyst and the process based on an a priori computer simulation.     

A DFT Study of Thiophene Adsorption on the Rh（111） Surfaces

Thiophene adsorption on the Rh(111) surfaces has been investigated by density functional theory.The results show that the adsorption at the hollow and bridge sites is the most stable.The molecular plane of the thiophene ring is distorted,the C=C bond is stretched to 1.448  and the C-C bond is shortened to 1.390.The C-H bonds tilt 22～42oaway from the surface.The calculated adsorption geometries are in reasonable agreement with population analysis and density of states.The thiophene molecule obtains 0.74 electrons,reflecting the interaction between the lone pair of sulfur and the d-orbitals of metal.The reaction paths and transition states for desulfurization of the molecule have been investigated.The bridge adsorption structure of thiophene leads to a thiol via an activated reaction with an energetic barrier of 0.30 eV.This second step is slightly difficult,and dissociation into a C4H4 fragment and a sulfur atom is possible,with an energetic barrier of 0.40 eV.     

SYNERGISTIC INTERACTIONS ON PHENOL ADSORPTION FROM AQUEOUS SOLUTIONS BY POLYMERIC ADSORBENTS

In this paper, the adsorption behaviors of phenol on polymeric adsorbents (Amberlite XAD4, NDA101, and D301)were investigated in batch system at 293, 303, and 313K, respectively. As the results shown, the adsorption isotherms of phenol on all adsorbents can be well fitted by Langmuir and Freundlich equations, which indicate a favorable and exothermic process. The adsorption capacity on a newly developed aminated adsorbent, NDA101, on which adsorption could be achieved by both hydrogen bonding interaction and π-π interaction, are higher than that on a weak base adsorbent, D301, on which adsorption could be achieved by hydrogen bonding interaction only, and on a nonpolar adsorbent, XAD4, on which adsorption could be achieved by π-π interaction only. The results of this paper indicate that the synergistic effect of some weak interactions, which occur simultaneously would contribute more to the adsorption than that occur individually.     

Adsorption Kinetics of Alkyl Polyglucoside at the Air—Solution Interface

The air-solution equilibrium tension γe and dynamic surface tension γt,of nonionic surfactant alkyl polyglucoside have been studied. γe was measured by the Wilhelmy method with Rruess K12 tensiometer. The CMC and the surface excesses T were determined from the surface tension vs. concentration curve. The γt decays were measured in the range 0.2-20s using a maximum bubble pressure instrument and analyzed with the Ward and Tordai equation.     

The Application of Polytetrafluoroethylene（PTFE） Fiber Grafted Acrylic Acid as a Cation Exchanger for Removing Cu^2＋

The polytetrafluoroethylene fiber grafted acrylic acid was used as a cation exchanger.The exchange capacity of the cation fiber is 3.06 mmol/g.The maximum Cu^2 adsorption capacity is 107.48mg/g.It could be desorbed completely by 1mol/L HCl.     

Dehydrodimers of arylaldoxime——a convenient source of iminoxy radicals

Arylaldoxime dehydrodimers 3a—1 have been prepared from the corresponding oximes 1a—1by using (HCrO_4)_2(Py)_4Co as oxidant.Their structures were assigned to be bisnitrone by XPS studies.ESR studies of 3a—1 in hot chloroform show that iminoxy radicals 2a—1 are formed.Therefore thedehydrodimers can provide a convenient source of these radicals.     

Chinese Journal of Polymer Science

Chinese Journal of Polymer Science (CJPS) is a bimonthly journal published in English and sponsored by the Chinese Chemical Society and the Institute of Chemistry, Chinese Academy of Sciences.CJPS is edited by a distinguished Editorial Board headed by Professor Fosong Wang and supported by an International Advisory Board in which many famous active polymer scientists all over the world are included.     

Chinese Journal of Polymer Science

1.Aims and Scope Chinese Journal of Polymer Science （CJPS） is a bimonthly journal published in English and sponsored by the Chinese Chemical Society and the Institute of Chemistry, Chinese Academy of Sciences. CJPS is edited by a distinguished Editorial Board headed by Professor Fosong Wang and supported by an International Advisory Board in which many famous active polymer scientists all over the world are included.     

Chinese Journal of Polymer Science

1 Aims and Scope Chinese Journal of Polymer Science （CJPS） is a bimonthly journal published in English and sponsored by the Chinese Chemical Society and the Institute of Chemistry, Chinese Academy of Sciences. CJPS is edited by a distinguished Editorial Board headed by Professor Fosong Wang and supported by an International Advisory Board in which many famous active polymer scientists all over the world are included.