Removal of Bisphenol A and its Reaction-Intermediates from Aqueous Solution by Ozonation

In this study, the oxidation of Bisphenol A (BPA) and its reaction-intermediates in aqueous solution by ozonation was investigated. The results of the study indicated that ozonation is effective in oxidizing BPA. Catechol, resorcinol, acetone, formaldehyde and organic acids, acetic, formic, maleic, and oxalic acid, are identified as reaction-intermediates. Ozonation of 51 μM (770 μM C) of BPA resulted in peak concentrations of 16.3, 8.7, 6.8, and 2.0 μM C of catechol, resorcinol, acetone, and formaldehyde, respectively. These concentrations correspond to 2.1, 1.1, 0.9, and 0.3% of the initial concentration of BPA in terms of total organic carbon for catechol, resorcinol, acetone, and formaldehyde, respectively. It was observed that BPA's reaction-intermediates were resistant to ozonation compared to the parent compound and complete mineralization of BPA may need extended ozonation.     

电子束固化双酚A环氧丙烯酸酯／聚丙烯酸酯体系的研究

本文以接枝型聚丙烯酸酯为主体同时加入双酚Ａ环氧丙烯酸酯,经过电子辐照同化后,形成的聚合物具有一定的剥离强度,持粘性和初粘性。     

Removal of Bisphenol A from Aqueous Solution by Molecularly Imprinted Polymers

Uniformly sized polymeric molecularly imprinted microspheres have been synthesized by membrane emulsification and suspension polymerization of methyl methacrylate and ethyl glycol dimethacrylate in the presence of bisphenol A as a template. At the beginning the best monomer compositions were selected by bulk polymerization of eight different mixtures of monomer and crosslinking agent. For the selected compositions that had the highest affinity to bisphenol A, a two-step process composed of membrane emulsification and suspension polymerization was used. Materials prepared by the two-step process showed the higher efficiency to the bisphenol A removal than their analogues prepared by bulk polymerization. The best material was synthesized from a mixture of methyl methacrylate and ethylene glycol dimethacrylate as 4:6 in the presence of n-octane as a solvent, and with 3 wt.% of bisphenol A. The logK_BPA value for this sample was 4.9. The experimental sorption isotherms were fitted by Scatchard plots and heterogeneity of the binding sites was determined. The selectivity of the sorbents to other phenols was demonstrated.     

Laccase immobilization on radiation synthesized epoxy functionalized polyethersulfone beads and their application for degradation of acid dye

The enzymatic degradation of textile dyes offers an alternative approach over the conventional waste water treatment processes. Covalent immobilization of the enzymes onto insoluble supports not only permits their reusability and easy separation of enzymes from the product but also, if properly performed, may improve their activities, stability and hence reduces the cost of process. In the present work, epoxy functionalized polyethersulfone (PES) was synthesized via radiation induced polymerization of poly(2,3-epoxypropyl methacrylate) [poly(EPMA)] in PES-NMP (N-methyl-2-pyrrolidone) solution using ⁶⁰Co-gamma radiation source. Poly(EPMA)-functionalized-PES [poly(EPMA)-f-PES] beads were fabricated via phase inversion route using water as the anti solvent. Laccase was covalently immobilized on to the beads via one step-room temperature coupling reaction of amine group of enzyme with the epoxy group of poly(EPMA). Enzyme activity was assayed using 2,2′-azino-bis(3-ethylthiazoline-6-sulfonate) (ABTS) as the substrate. Effect of temperature and pH on the free and immobilized enzyme activity was studied. The immobilized laccase was successfully employed to degrade Acid Red 1 (AR1) dye in aqueous solution. Room temperature incubation of the laccase immobilized poly(EPMA)-f-PES beads with AR1 dye (∼10 ppm) resulted in ∼88% degradation of the dye over a period of 15 days.     

A new nanosensor composed of laminated samarium borate and immobilized laccase for phenol determination

A new nanosensor composed of laminated samarium borate and immobilized laccase was developed for phenol determination. The laminated samarium borate was synthesized by a mild solid-state-hydrothermal (S-S-H) method without any surfactant or Template. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to characterize the samples. The morphology of the as-prepared materials was characterized by SEM, which shows that laminated samarium borate are uniform nanosheets with a layer-by-layer self-assembled single-crystal structure. These laminated samarium borate have typical diameters of 3 ~ 5 μm and the thickness of each layer is in the range of 10 ~ 80 nm. And then, these SmBO₃ multilayers were used to immobilize the laccase. The proposed nanosensor composed of laminated samarium borate and immobilized laccase was successfully developed for phenol determination. Cyclic voltammetry were used to study the nanosensor. The proposed nanosensor displayed high sensitivity toward phenolic compounds. The linearity of the nanosensor for the detection of hydroquinone was obtained from 1 to 50 μM with a detection limit of 3 × 10^-7 M (based on the S/N = 3).     

Adsorption Studies on the Removal of an Endocrine-Disrupting Compound (Bisphenol A) using Activated Carbon from Rice Straw Agricultural Waste

In this study, we used a two-stage process and potassium hydroxide (KOH) to transform waste biomass (rice straw) into activated carbon and then evaluated the adsorption capacity of the waste for removing bisphenol A (BPA) from an aqueous solution. Activated carbon removed BPA rapidly and effectively because of its high surface area and an adsorptive capacity (181.19 mg/g) that is significantly higher than many other adsorbents that have been developed in the recent past. The native and BPA-loaded adsorbents were characterized by scanning electron microscopy, elemental analysis, and Fourier transform infrared. Different adsorption parameters, such as the initial BPA concentration, contact time, temperature, and pH for BPA adsorption, were studied using a batch system. Equilibrium adsorption isotherms (Langmuir, Freundlich, and Temkin) and kinetics were investigated. The Langmuir model fits the experimental results well, compared to the Freundlich and Temkin models, and a pseudo-second-order equation was successfully used to describe the results of the kinetic studies. This study demonstrates that activated carbon produced from rice straw can be very effective in the adsorption of BPA from aqueous solution.     

Miscibility enhancement on the immiscible binary blend of poly(vinyl acetate) and poly(vinyl pyrrolidone) with bisphenol A

The miscibility behavior and hydrogen bonding of ternary blends of bisphenol A (BPA)/poly(vinyl acetate) (PVAc)/poly(vinyl pyrrolidone) (PVP) were investigated by using differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR). The BPA is miscible with both PVAc and PVP based on the observed single T_g over the entire composition range. FTIR was used to study the hydrogen-bonding interaction between the hydroxyl group of BPA and the carbonyl group of PVAc and PVP at various compositions. Furthermore, the addition of BPA is able to enhance the miscibility of the immiscible PVAc/PVP binary blend and eventually transforms into miscible blend with single T_g, when a sufficiently quantity of the BPA is present due to the significant Δχ and the ΔK effect.     

电纺制备苯乙烯甲基丙烯酸共聚物单轴定向纳米纤维

采用无皂乳液法合成了带有羧基的苯乙烯-甲基丙烯酸共聚物,并利用静电纺丝技术,得到了不同形貌的直径约为800nm的纳米纤维。同时通过对传统的平面导体收集装置的改进,得到了大面积、单轴定向的功能纳米纤维。     

液质法测定塑料包装饮用水和饮用水塑料接触制品中双酚A、双酚F和双酚S的迁移量

建立了液相色谱-串联质谱(HPLC-MS/MS)法同时测定塑料包装饮用水和饮用水塑料接触制品中双酚A(BPA)、双酚F(BPF)和双酚S(BPS)的特定迁移量。优化比较了色谱柱类型和滤膜材质分别对色谱峰形和回收率的影响。包装饮用水样品和饮用水塑料接触制品浸泡液样品,过亲水性聚四氟乙烯针头滤膜后直接进样,以甲醇和水为流动相在苯基柱上梯度洗脱,BPA、BPF和BPS在9.5 min内达到基线分离,串联质谱在ESI-和MRM模式下进行检测。BPA、BPF和BPS在25~100μg/L范围,相关系数r≥0.999 0,定量限范围为0.07~0.52μg/kg,15、30和60μg/kg的3水平加标回收率范围为88.3%~108%,RSD为0.32%~2.62%。该方法色谱分离效果好,快速、简便、重复性好、准确度高,定量限满足现行标准法规的限量要求,并已用于包装饮用水和饮用水塑料接触制品中BPA、BPF和BPF的检测。     

Surface Modification of Synthesized Nanozeolite NaX with TEAOH for Removal of Bisphenol A

In the present study, the surface modification of a freshly synthesized nanozeolite NaX was done with tetraethylammonium hydroxide (TEAOH) and applied as an adsorbent for the removal of bisphenol A (BPA) from its aqueous solutions. The adsorbent was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicated that the synthesized adsorbent can remove BPA rapidly and effectively because of its high surface area (572 m²/g) and small particle size (35 nm). Uptake of BPA was greatly influenced by pH, stirring rate, temperature, contact time, and adsorbent dose. The optimum values of these parameters were 10.5 pH, 250 rpm, 25°C, 2 h, and 0.6 g/L. The adsorption was found to be spontaneous and exothermic. The Freundlich isotherm model and pseudo-first-order kinetic model fitted the experimental results well. The monolayer and multilayer adsorption capacities were found to be 42.8 and 122.6 mg/g, respectively.     

高效液相色谱法测定双酚A中的杂质

提出一种高效液相色谱法，能有效分离和定量检测双酚Ａ中的三项杂质含量，本方法采用Ｃ＿（１８）反相柱和由甲醇：水为６５：３５组成的淋洗液用ＵＶ检测器在２８０ｎｍ处检测双酚Ａ中的２，４－双酚Ａ，三酚和色满三项杂质。     

双酚A的电化学行为及其测定

用溶剂热法合成PtNi纳米颗粒,将其修饰在玻碳电极表面制成电化学传感器并将其用于检测。探讨了测试底液、富集电位以及富集时间等实验条件对传感器性能的影响。结果表明,在电位为0.5V条件下,该传感器检测双酚A的线性范围为0.99⁹ 9.9×1 0-6mol/L,其检测限为3.3 6×1 0-7mol/L。该传感器选择性好、灵敏度高、具有良好的重现性和稳定性。     

双酚A二氰酸酯的固化与催化研究

运用红外光谱(IR)和差热分析(DTA)等手段研究了自制的双酚A二氰酸酯(BCE)树脂提纯前后的固化反应特性，并探讨了金属催化剂的催化作用。结果表明，提纯将降低BCE树脂中双酚A等杂质的含量，提高固化反应温度，提高树脂的耐热性；环烷酸钴对BCE树脂的固化有明显的催化作用，加入后固化反应放热峰起始温度Ti由207．2℃降低到167．8℃，凝胶时间大大降低。     

活性白土法提纯双酚A

用活性白土做脱酚剂去除双酚Ａ中的微量苯酚及其杂质,其去除率可达９９％以上。     

双酚A型二胺和二酐合成可溶性聚酰亚胺的研究

采用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)和2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)为单体,N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,并分别经热亚胺化和化学亚胺化过程合成了双酚A型聚酰亚胺(PI).用FTIR、DSC、TGA等对聚合物的结构和性能进行了表征.F...     

Miscibility with positive deviation in Tg-composition relationship in blends of poly(2-vinyl pyridine)-block-poly(ethylene oxide) and poly(p-vinyl phenol)

Phase behavior and miscibility with positive deviation from linear T_g-composition relationship in a copolymer/homopolymer blend system, poly(2-vinyl pyridine)-block-poly(ethylene oxide) (P2VP-b-PEO)/poly(p-vinyl phenol) (PVPh), were investigated by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR) and solid-state ¹³C nuclear magnetic resonance (¹³C NMR), optical microscopy (OM), and scanning electron microscopy (SEM). Optical and electron microscopy results as well as NMR proton spin-lattice relaxation times in laboratory frame () all confirmed the miscibility as judged by the T_g criterion using DSC. In comparison to the literature result on a homopolymer/homopolymer blend of P2VP/PVPh, fitting with the Kwei equation on the T_g-composition relationship for the block-copolymer/homopolymer blend of P2VP-b-PEO/PVPh blend system yielded a smaller q value (q = 120) for P2VP-b-PEO/PVPh than that for P2VP/PVPh blend (q = 160). The FT-IR and ¹³C NMR results revealed hydrogen-bonding interactions between the pendant pyridine group of P2VP-b-PEO and phenol unit in PVPh, which is responsible for the noted positive deviation of the T_g-composition relationship. Comparison of the shifts of hydroxyl IR absorbance band, reflecting the average strength of H-bonding, indicates a decreasing order of P2VP/PVPh > P2VP-b-PEO/PVPh > PEO/PVPh blends. The PEO block in the copolymer segment tends to defray the interaction strength in the P2VP-b-PEO/PVPh blends because of relative weaker interaction between PEO and PVPh than that between P2VP and PVPh pairs. A comparative ternary (P2VP/PEO)/PVPh blend was also studied as the controlling experiments for comparison to the P2VP-b-PEO/PVPh blend. The thermal behavior and interaction strength in (P2VP/PEO)/PVPh ternary blends are discussed with those in the P2VP-b-PEO/PVPh copolymer/homopolymer blend.     

双酚A的生产、消费及技术进展

分析了双酚A国内外生产及消费趋势,评述了双酚A各种合成工艺技术路线,并重点介绍了最先进的离子交换树脂法工艺技术进展,对中国双酚A的生产提出几点建议。     

Modified poly(3-hydroxybutyrate-co-3-hydroxyvalerate) using hydrogen bonding monomers

Properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were significantly modified by a hydrogen bonding (H-bond) monomer-bisphenol A (BPA). BPA lowered the T_m of PHBV and widened the heat-processing window of PHBV. At the same time, a dynamic H-bond network in the blends was observed indicating that BPA acted as a physical cross-link agent. BPA enhanced the T_g of PHBV and reduced the crystallization rate of PHBV. It resulted in larger crystallites in PHBV/BPA blends showed by WAXD. However, the crystallinity of PHBV was hardly reduced. SAXS results suggested that BPA molecules distributed in the inter-lamellar region of PHBV. Finally, a desired tension property was obtained, which had an elongation at break of 370% and a yield stress of 16 MPa. By comparing the tension properties of PHBV/BPA and PHBV/tert-butyl phenol blends, it was concluded that the H-bond network is essential to the improvement of ductility.     

纳米铜/碳纳米管修饰电极测定双酚A

实验制备了纳米铜/碳纳米管/Nafion膜修饰电极。研究了在修饰电极上双酚A的电化学特性。实验采用循环伏安法研究双酚A的电化学行为,研究发现在pH值为7.0的PBS缓冲溶液中,双酚A的浓度与峰电流值在2.0×10-7~2.0×10-5mol/L范围呈现良好的线性关系,最低检测限3.3×10-8mol/L。用此电极对实际样品中双酚A的含量进行了测定,效果满意。     

粉煤灰固定化细胞去除聚乙烯醇的研究

前期研究分离到一株能高效降解并矿化聚乙烯醇(PVA)的黄单胞菌(Xanthomonas sp.)。考察了利用改性处理或未处理粉煤灰吸附该菌株去除PVA的特性。结果表明,实验所采用的5种粉煤灰对该菌细胞等温吸附方程与Langmuir方程、Freundlich方程的拟合都达到很高的水平。改性粉煤灰对菌体细胞的吸附量由大到小的顺序为HC l处理粉煤灰>H2SO4处理粉煤灰>Ca(OH)2处理粉煤灰>NaOH处理粉煤灰>未处理粉煤灰。在培养初期,粉煤灰固定化细胞对PVA的去除量略低于等量游离细胞,但其去除速率的变化与游离细胞基本相同。