Equilibrium Adsorption Method Research Articles

Uniformly Distributed Palladium Nanoparticles on NH2‐MIL‐53 Fabricated by an Equilibrium Adsorption Method for Reduction of Nitrite in Water

Metal particle on a support material should be small and homogeneous in size, which is desirable when using it as a catalyst. In this study, we investigated to introduce Pd nanoparticles (NPs) with narrow size distribution into NH2‐MIL‐53, which was prepared by the reaction of aluminum(III) nitrate with 2‐aminoterephthalic acid. Only by immersing it in an aqueous PdCl2 solution, followed by the reduction with NaBH4, Pd NPs of about 2 nm with unform distribution were formed in NH2‐MIL‐53 up to 3.5 wt.% Pd loadings. Amino group on the linkers in NH2‐MIL‐53 played a critical role for the introduction of (PdCl3)– as a precursor for Pd NPs, while no Pd was introduced into MIL‐53 without amino group. The obtained catalysts (Pd@NH2‐MIL‐53) showed high catalytic performance for reduction of nitrite in water. The specific activity per Pd site exposed on the surface changed greatly depending on the Pd loadings despite the size of Pd NPs unchanged. Pd@NH2‐MIL‐53 with low Pd loadings showed higher specific activity (TOF = 2.9×102 h‐1), which might be due to the preferential exposure of Pd(111) facet on Pd NPs.

A site distance dependence of product selectivity in n-hexane dehydrogenation over alumina-supported chromium catalyst

Although CrOx/Al2O3 has been widely applied for light alkanes dehydrogenation, there is insufficient understanding on the dehydrogenation of long-chain alkanes that no solutions to the poor selectivity to mono-olefins and high yield of aromatics. Herein, dehydrogenation of n-hexane was studied on a series of CrOx/γ-Al2O3 catalysts with different densities of Cr sites, and it finds that the dehydrogenation performance is closely related to the distance between Cr sites. With densely populated Cr sites, multiple H atoms of n-hexane are adsorbed on the CrOx/γ-Al2O3 simultaneously (i.e., multi-point adsorption), promoting the formation of n-hexadiene, n-hexatriene and the resultant benzene and/or coke. Therefore, when the Cr loading exceeds the mono-layer coverage (5 wt% Cr loadings), the selectivities to n-hexenes and benzene are kept constant (about 23 wt% and 68 wt%, respectively). While decrease of Cr content in the mono-layer regime leads to a significant decrease in both the distance between Cr sites and the number of adsorbed H atoms, resulting in improved selectivity to n-hexenes. The CrOx@γ-Al2O3 catalyst with 3.6 Cr atoms/nm2 prepared by the equilibrium adsorption method (and the complexation of CrIII and 3,5-dimethylpyridine), exhibits 89 wt% selectivity to n-hexenes (<2 wt% for benzene). This work provides theoretical guidance for the precise design and synthesis of the high-performance CrOx-based catalyst for the dehydrogenation of alkanes, especially for long-chain alkanes.

Design of active phase structure with high activity and stability in residue hydrotreating reactions

The catalyst with well-dispersed (Ni)MoS2 active phase characteristic of short slab length and low stacking numbers was designed by strengthening metal-support interaction (MSI) and metal dispersion, which displayed high activity and long-term stability in real-life residue hydrodesulfurization (HDS) reactions. Furthermore, the impacts of pseudo-boehmite and catalyst calcination temperature on surface properties were thoroughly investigated. Mo equilibrium adsorption method, Al27 NMR, XRD, Raman, UV–Vis DRS, and H2-TPR characterization showed that the hydroxyl groups concentration and tetrahedral cation vacancies increased upon reducing the pseudo-boehmite extrudates calcination temperature. Increasing calcination temperature of the catalysts further strengthened MSI, resulted in well-dispersed Mo species with enhanced MSI. Therefore, well-dispersed (Ni)MoS2 active phase was acquired on novel designed catalyst. XPS coupled with HRTEM indicated that the more potential active sites, less propensity for active phase evolution and gradual increase in sulfidation degree with processing time contributed to the high HDS performance of the designed active phase. This work can deepen our understanding toward evolution pattern of active phase during residue HDS catalysts, and give guidance for developing high performance catalyst by strengthening MSI and enhancing metal dispersion.

Investigation of Bioactive Complexes of Chitosan and Green Coffee Bean or Artichoke Extracts.

The formation of water-insoluble complexes between chitosan (ChS) and caffeoylquinic acid (CQ) derivatives present in artichoke (AE) and green coffee bean (GCBE) extracts was investigated by the equilibrium adsorption method. The UPLC/HPLC analysis revealed that the phenolic compounds accounted for 8.1% and 74.6% of AE and GCBE respectively, and CQ derivatives were the predominant compounds. According to the applied Langmuir adsorption model, anionic compounds present in natural extracts were adsorbed onto the active centers of ChS, i.e., primary amino groups. The driving forces of adsorption were electrostatic interactions between cationic groups of ChS and anionic compounds of natural extracts. Chromatographic analysis revealed that not only CQ derivatives, but also other phenolic compounds of natural extracts were attached to ChS. The release of adsorbed compounds into different media as well as the bioactive properties of complexes were also studied. With the immobilization of bioactives onto ChS, increased and prolonged ABTS•+ radical scavenging activity and decreased antifungal activity against Fusarium graminearum and Botrytis cinerea were observed compared to those of ChS. The findings of the current study highlight that the adsorption approach could be used to successfully prepare water-insoluble complexes of ChS and components of natural extracts with prolonged antioxidant activity.

Synthesis of MRGO@ZIF-7-Based Molecular Imprinted Polymer by Surface Polymerization for the Fast and Selective Removal of Phenolic Endocrine-Disrupting Chemicals from Aqueous Environments

In this study, Zn(NO3)2·6H2O was selected as the metal source, and ZIF-7-modified magnetic graphene-based matrix materials (MRGO@ZIF-7) were prepared by in situ growth. ZIF-7 modified magnetic graphene-based molecular imprinting complexes (MRGO@ZIF7-MIP) were successfully synthesized by a surface molecular imprinting technique using bisphenol A (BPA) as the template molecule. The obtained experimental materials were characterized by X-ray diffraction (XRD), Brunner–Emmet–Teller (BET) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS). The proper adsorption and selective recognition ability of the MRGO@ZIF7-MIP were studied by an equilibrium adsorption method. The obtained MRGO@ZIF7-MIP showed significant molecular recognition of bisphenol A (BPA) and good selectivity and reproducibility for BPA in different aqueous environments such as drinking water, river water, and lake water. These properties make this material potentially applicable for the efficient removal of phenolic endocrine disruptors in real water environments.

Binary Adsorption and Migration Simulation of Levofloxacin with zinc at Concentrations Simulating Wastewater on Silty Clay and The Potential Environmental Risk in Groundwater

Migration of soil pollutants can cause groundwater pollution, which is dominated by the soil adsorption of pollutants. Heavy metals and fluoroquinolone antibiotics exist in the soil and form compound pollution, with different adsorption behaviors in the soil. It may make the levofloxacin (LVFX) migration and potential risk of LVFX to groundwater change. Therefore, this research on Zinc (Zn/Zn2+) and LVFX studied the binary adsorption on silty clay in the vadose zone using the batch equilibrium adsorption method. Besides, Hydrus-1D simulate vertical migration. As the results show: (1) Silty clay has excellent storage capacity (adsorption rate>90%) for LVFX and is a natural barrier to reducing groundwater risk; (2) Binary adsorption of LVFX with Zn on silty clay had could be influenced by metallic oxide, pH value, and cation species. The metallic oxides adsorption rate decreased by 10.3%; Compared with single adsorption, Zn2+ promoted the adsorption of LVFX on silty clay, with the exception that the pH value was 2.0; Based on the simulated migration, subtle changes in adsorption may lead to a significant difference in migration and impact on the environmental risk of LVFX to groundwater. This paper proposed three aspects of the research should be strengthened to further develop the potential of silty clay in the prevention and control of groundwater pollution.

Defluoridation Proficiency of Ocimum tenuiflorum Based Bioadsorbent against Fluoride Toxicity in Drinking Water

From the past century, the global attention shifted towards fluoride toxicity through drinking water due to its severity in important health concerns. Many researchers made an attempt to resolve the issue to potable drinking water through many chemical and mechanical methods. Among them adsorption is one of the acceptable cheap and cost-effective method to remove the fluoride from its contaminated waters. This article presents a remarkable defluoridation techniques and approach by preparing efficient bioadsorbent from Holy Basil Ocimum tenuiflorum L. leaves. Thermo-charring method was followed to prepare bioadsorbent from holy basil and avoided acid charring method. With this bioadsorbent, batch equilibrium adsorption method was followed by varying the adsorbent and adsorbate (fluoride) concentrations, its contact time, different adsorbent dose and its different sizes. As a sum up, the best contact time was identified as 90 minutes for all fluoride concentrations. As known, the smaller size adsorbent has shown good absorptivity and the quantity of 1.5 g/L found to be optimal amount for the effective defluoridation. The interference of co-existing anions like nitrates, chlorides, sulphates and carbonates were also studied to identify the applicability of prepared bioadsorbent at real water environment. The co-ions nitrates and chlorides did not affect the adsorptive efficiency, but sulphates and carbonates suffered lot due to its bulky structured binding on adsorbent and lacked the fluoride adsorption onto it. The spectral and morphological characterizations such as FTIR, XRD and SEM-EDAX spectral studies carried out to confirm the surface variations of bioadsorbent and their corresponding reports reveal the notable observations. The best optimal defluoridation capacity for Ocimum tenuiflorum based bioadsorbent was found to be 1766 mg/kg.

Immobilization of Ir(OH)3 Nanoparticles in Mesospaces of Al-SiO2 Nanoparticles Assembly to Enhance Stability for Photocatalytic Water Oxidation

Iridium hydroxide (Ir(OH)3) nanoparticles exhibiting high catalytic activity for water oxidation were immobilized inside mesospaces of a silica-nanoparticles assembly (SiO2NPA) to suppress catalytic deactivation due to agglomeration. The Ir(OH)3 nanoparticles immobilized in SiO2NPA (Ir(OH)3/SiO2NPA) catalyzed water oxidation by visible light irradiation of a solution containing persulfate ion (S2O82−) and tris(2,2′-bipyridine)ruthenium(II) ion ([RuII(bpy)3]2+) as a sacrificial electron acceptor and a photosensitizer, respectively. The yield of oxygen (O2) based on the used amount of S2O82− was maintained over 80% for four repetitive runs using Ir(OH)3/SiO2NPA prepared by the co-accumulation method, although the yield decreased for the reaction system using Ir(OH)3/SiO2NPA prepared by the equilibrium adsorption method or Ir(OH)3 nanoparticles without SiO2NPA support under the same reaction conditions. Immobilization of Ir(OH)3 nanoparticles in Al3+-doped SiO2NPA (Al-SiO2NPA) results in further enhancement of the catalytic stability with the yield of more than 95% at the fourth run of the repetitive experiments.

Enantiospecific equilibrium adsorption and chemistry of d-/l-proline mixtures on chiral and achiral Cu surfaces.

A fundamental understanding of the enantiospecific interactions between chiral adsorbates and understanding of their interactions with chiral surfaces is key to unlocking the origins of enantiospecific surface chemistry. Herein, the adsorption and decomposition of the amino acid proline (Pro) have been studied on the achiral Cu(110) and Cu(111) surfaces and on the chiral Cu(643)R&S surfaces. Isotopically labelled 1-13 C-l-Pro has been used to probe the Pro decomposition mechanism and to allow mass spectrometric discrimination of d-Pro and 1-13 C-l-Pro when adsorbed as mixtures. On the Cu(111) surface, X-ray photoelectron spectroscopy reveals that Pro adsorbs as an anionic species in the monolayer. On the chiral Cu(643)R&S surface, adsorbed Pro enantiomers decompose with non-enantiospecific kinetics. However, the decomposition kinetics were found to be different on the terraces versus the kinked steps. Exposure of the chiral Cu(643)R&S surfaces to a racemic gas phase mixture of d-Pro and 1-13 C-l-Pro resulted in the adsorption of a racemic mixture; i.e., adsorption is not enantiospecific. However, exposure to non-racemic mixtures of d-Pro and 1-13 C-l-Pro resulted in amplification of enantiomeric excess on the surface, indicative of homochiral aggregation of adsorbed Pro. During co-adsorption, this amplification is observed even at very low coverages, quite distinct from the behavior of other amino acids, which begin to exhibit homochiral aggregation only after reaching monolayer coverages. The equilibrium adsorption of d-Pro and 1-13 C-l-Pro mixtures on achiral Cu(110) did not display any aggregation, consistent with prior scanning tunneling microscopy (STM) observations of dl-Pro/Cu(110). This demonstrates convergence between findings from equilibrium adsorption methods and STM experiments and corroborates formation of a 2D random solid solution.

Adsorption of enrofloxacin on acid/alkali-modified corn stalk biochar

The levels of enrofloxacin have exceeded acceptable standards in the water environment of many global regions, and the problem of pollution caused by enrofloxacin needs to be solved urgently. In this study, phosphoric acid and potassium hydroxide were used to modify corn stalk biochar. The properties and structure of the modified biochar were studied by scanning electron microscopy, infrared spectrometer, X-ray diffraction spectroscopy, and other analytical methods. Other factors influencing enrofloxacin adsorption were assessed using the equilibrium adsorption method. The surface area of the acid- and alkali-modified biochar was found to increase 10- and 14-fold, respectively. The equilibrium adsorption capacity of enrofloxacin on the acid- and alkali-modified biomass carbon increased by 27.80% and 54.08%, respectively. The quasi-second-order kinetic equation and Langmuir equation described the adsorption process of the biochars accurately. At pH = 5.0, the biochars had the highest levels of enrofloxacin adsorption. The adsorption of enrofloxacin onto the biochars negatively correlated with the concentration of Ca2+ in the background solution.

Electrochemical analysis of the porphyrazine-induced enhancement of ORR activity of Pt catalysts for the development of porphyrazine-adsorbed Pt catalysts

The enhancement of the oxygen reduction reaction (ORR) activity of Pt catalysts by porphyrazines (tetraazaporphyrin and phthalocyanine) is analyzed electrochemically. While tetra(t-butyl)tetraazaporphyrin significantly enhances the ORR activity, the enhancement by dilithium phthalocyanine is limited; this molecule increases the ORR at high potentials but decreases it at low potentials. The cyclic voltammograms (CVs) under an Ar atmosphere and a Tafel analysis reveal that the phthalocyanine promotes the ORR by destabilization of OHad, an intermediate of the ORR, at high potentials. However, this positive effect of the phthalocyanine is counteracted by its inhibitory effects at low potentials. Thus, the tetra(t-butyl)tetraazaporphyrin, which does not have a significant inhibitory effect, would be a better enhancer. The method for preparing tetra(t-butyl)tetraazaporphyrin-adsorbed Pt catalysts was investigated. This molecule is not only mainly adsorbed on a carbon black support, but also adsorbed on the surface of Pt nanoparticles. Tetra(t-butyl)tetraazaporphyrin-adsorbed carbon-supported Pt nanoparticles are prepared by an equilibrium adsorption method and an evaporation-to-dryness method. The optimized preparation method is discussed. Using the evaporation-to-dryness method, we also examined the effects of several porphyrins on the ORR of Pt catalysts.

Electrospinning of highly dispersed Ni/CoO carbon nanofiber and its application in glucose electrochemical sensor

In this work, a common anionic surfactant SDS was used as one of a precursor, combining anionic surfactant-assisted equilibrium adsorption method and electrospinning method to fabricate highly dispersed Ni/CoO loaded carbon nanofiber. Through this approach, Ni/CoO can uniformly in-situ grow on the surface of the carbon nanofiber. Compared with the hydrothermal method, this method is more simple and stronger. Thus, the as prepared Ni-CoO/CNF exhibits an excellent catalytic activity and sensitivity for determination of glucose. Furthermore, we investigated the effect of different amounts of surfactants on the morphology of the material and its effect on the glucose current response. Under optimal conditions, Ni-CoO/CNF showed a good linear range from 0.25 μΜ to 600 μΜ and an extremely low detection limit of 0.03 μΜ, which make it possible for determination of samples with low glucose concentration.

Adsorption behavior and selectivity mechanism of flotation reagents applied in ternary plastic mixtures

Plastic flotation attracts increasing attention in the process of recycling and will bring potential application in industry after theoretical perfection. For a separated ternary system of polyethylene terephthalate (PET), polyvinyl chloride (PVC) and polyethylene (PE), adsorption behavior and selectivity mechanism of flotation reagents were investigated by multi-characterization tests and batch equilibrium adsorption method. Quantitative adsorption results indicate that frother polyethylene glycol (PEG) only acts on gas and liquid phases in the flotation system with negligible adsorption capacity onto solid phase. For depressant sodium lignosulphonate (SL), the pseudo-first-order and Langmuir isotherm models are suitable for corresponding kinetic and equilibrium data of PET or PVC. Thermodynamic parameters further indicate that the adsorption of SL is a spontaneous and endothermic process, which neither belongs to the pure physisorption nor to the pure chemisorption. Adsorption models of SL were established based on hydrogen bond, with three clear bonding types (OH…π*, OH…O, and OH…Cl). Selectivity mechanism can be attributed to the selective hydrogen bond acceptors and donors, which are provided by specific plastic and depressant, respectively. In the light of these theoretical fundings, new targeted reagents or pre-treatments are expected to be developed towards more complex flotation system.

In situ generation of COx-free H2 by catalytic ammonia decomposition over Ru-Al-monoliths

Ru catalysts supported on alumina coated monoliths has been prepared employing three different precursor, which are ruthenium chloride, ruthenium nitrosyl nitrate and ruthenium acetyl acetonate, by an equilibrium adsorption method. The Ru particle sizes could be controlled varying the metal precursor salt. Among the prepared catalysts, Ru catalyst prepared from nytrosyl nitrate exhibited the highest activity which is concomitant to the largest mean Ru particle size of 3.5 nm. The values of the apparent activation energy calculated from the Arrhenius equation are according to the Temkin-Phyzev model, indicating that the recombinative desorption of N ad-atoms is the rate-determining step of the reaction. However, the ratio between the kinetic orders with respect to ammonia and hydrogen (−α/β), is not in agreement to the valued predict by Temkin formalism. This fact could be related to the different operational conditions used during the reaction, and/or catalyst nature, but not to any change on the controlling step of the reaction.

An anionic surfactant-assisted equilibrium adsorption method to prepare highly dispersed Fe-promoted Ni/Al2O3 catalysts for highly selective mercaptan removal

This article proposes a novel sodium dodecylbenzenesulfonate (SDBS)-assisted equilibrium adsorption method for preparing highly dispersed Ni/Al2O3 and Fe-promoted NiFe/Al2O3 thioetherification catalysts. The proposed strategy anchors nickel cations onto the electronegative surface of an Al2O3 support modified by negatively charged DBS− bilayers. As a result, this method achieves highly dispersed Ni nanoparticles without strengthening the metal-support interaction, promoting the reducibility and sulfurization of the supported Ni species. The as-prepared Ni-based catalysts have a smaller size, a higher dispersion of metal nanoparticles, and a greater amount of active metal sulfides than their counterparts prepared by the conventional impregnation method, endowing them with excellent catalytic performance for the highly selective removal of mercaptans. This method provides a new opportunity to prepare highly dispersed metal nanoparticles without a strong metal-support interaction.

Effect of support in Ni-Bi-O/support catalyst on oxidative dehydrogenation of n-butane to butadiene

NiO-Bi2O3/different support catalysts, 20wt% Ni and 30wt% Bi as metal weight to support weight (hereafter 20wt%Ni-30wt%Bi-O/support) have been studied for oxidative dehydrogenation of n-butane to butadiene. Al2O3, SiO2, ZrO2 and none (: without support) were served as gel and sol type supports. As the results, activity and selectivity of oxidative dehydrogenation of n-butane to butadiene over the Ni-Bi-O/support catalyst strongly depended on the supports. The order of the butadiene selectivity as gel-type support was Al2O3>SiO2>ZrO2≫none, while SiO2 showed the highest butadiene selectivity from 1-butene feedstock. The gel-type support effect as a hierarchical nano-particle cohabitation was also studied by using equilibrium adsorption method for the Ni-Bi-O impregnation. In the sol-type support case, the order is SiO2>Al2O3>ZrO2, where the SiO2 sol shows not only superior to gel-type but also the best performance (n-butane conversion: 35.6%, selectivity: dehydrogenation 78.3%, butadiene 41.6%) among support types and species. The sol-type SiO2 hold balanced acid and base sites cooperating to improve butadiene selectivity, with oxygenate suppressed by accelerating redox system with non-hierarchical nano-particle cohabitation of NiO, Bi6O7 and support SiO2.

MoOx/TiO2 immobilized on quartz support as structured catalyst for the photocatalytic oxidation of As(III) to As(V) in aqueous solutions

In the present paper, a stable MoOx/TiO2 photocatalyst, active in the photocatalytic oxidation of As(III) to As(V), was successfully immobilized on quartz flakes and tested under different UV irradiation intensities and initial As(III) concentration. The structured photocatalyst was prepared in two steps, realizing a coating of TiO2 on quartz flakes by sol–gel method, and then transferring the molybdenum species through an equilibrium adsorption method. The obtained samples were characterized by SEM–EDAX analysis, N2 adsorption at −196°C and Laser Raman spectra. SEM–EDAX results showed the preferential interaction between Mo species and titania layer and a very good dispersion of MoOx on the TiO2 film deposited on the transparent support. Raman spectra confirmed the presence of hydrated octahedrally polymolybdate species well anchored to the TiO2 surface. Photocatalytic oxidation tests showed that the complete conversion of As(III) to As(V) was achieved in the presence of MoOx/TiO2 catalyst supported on quartz flakes within 120min of UV irradiation. The catalyst maintained an excellent photocatalytic activity and durability after four cycles in aerated water avoiding the photoreduction of the MoOx species. The developed structured photocatalyst can be easily separated from the reaction mixture, making it a very promising catalyst to be employed in continuous reactors for the photocatalytic treatment of arsenic polluted water.

Chitosan-nanosilica hybrid materials: Preparation and properties

The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO2, TiO2/SiO2 and Al2O3/SiO2). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area SBET of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface.

Effect of the composition and conditions of the synthesis of porous glass on their micro- and mesoporous structures

Micro- and mesoporous substructures of porous glass (PG) obtained from two-phase alkali-borosilicate glass of various compositions as the result of their through acidic leaching under various conditions have been studied using equilibrium and kinetic adsorption and desorption methods. It has been determined that for all the studied PG samples multimodal mesopore size distribution (up to four modes) and micropores (up to three modes) is intrinsic. The effective diameters of the mesopores vary from 3 to 60 nm. The diameters of micropores vary within small ranges from 0.5 to 0.7 nm. It has been stated that micropores in PG mainly represent the ranges of the interglobular contacts of secondary silica with sizes of 1–2 diameters of the adsorbate molecule. It has been shown that varying the composition of the initial alkali-borosilicate glass by the additions of doping elements (lead, aluminum, fluorine, and phosphorus) and changing the temperature conditions of liquation, one can modify the parameters of the morphology of the pores and ratio between mesoporous and microporous substructures of PG in broad ranges.

Preparation of molecularly imprinted polymer for vanillin via seed swelling and suspension polymerization

Molecularly imprinted polymer (MIP) for vanillin was synthesized successfully by multi-step swelling suspension polymerization using polystyrene (PS) as the “seed”. The PS-MIP was characterized by scanning electron microscopy and equilibrium adsorption method. The results showed that the PS-MIP microsphere had regular spherical morphology and can selectively separate the target analytes. The PS-MIP had two kinds of binding sites, while the non-imprinted polymer using PS as the “seed” (PS-NMIP) only had one kind of binding sites by Scatchard analysis which indicated that specific and non-specific binding interactions existed there. The PS-MIP had proven to show improved binding capacity in comparison with the MIP synthesized by bulk polymerization.