Adsorption thermodynamics and kinetic investigation of aromatic amphoteric compounds onto different polymeric adsorbents

The adsorption behavior ofp-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.

CATIONIC RING-OPENING POLYMERIZATION OF TETRAHYDROFURAN WITH KEGGIN-TYPE HETEROPOLYCOMPOUNDS AS SOLID ACID CATALYSTS

Three Keggin-type heteropolyanions, namely H3PMo12O40-13H2O, （NH4）3PMo12O40·4H2O and H3PW12O40·13H2O were prepared and tested in the ring-opening polymerization reaction of tetrahydrofuran. The effects of the counter-cation （H＋, NH4＋） and the peripheral atoms （Mo, W） on the polymerization were investigated. It has been found that when the protons of H3PMo12O40·13H2O were replaced by the ammonium cations the polymerization rate decreased dramatically. Whereas, when the peripheral atoms （Mo） were replaced by their homologous （W）, the polymerization rate increased twofold. As for the viscosity average molecular weight （My） of polymer products, it was found that the high molecular weight （7930） was obtained by using H3PW12O40·13H2O. The molecular weight （My） obtained by H3PMo12O40·13H2O and （NH4）H3PMo12O40·13H2O was 6470 and 6810, respectively.

In situ polymerization coating and characteristics of coated NPK compound fertilizer

Controlled release NPK compound fertilizers were prepared by means of in situ polymerization of monomers on the surface of fertilizer granules at room temperature. Methacrylate, α-methyl acrylic acid, and ethylene dimethylacrylate were used as monomers, Dibenzoyl peroxide as initiator, and cobalt naphthenate, and triethyl amine as promoters. The structures of coating materials were characterized by IR spectra. The thermogravimetric analysis result indicated that the coating materials were of good thermal stability. The mean thickness of single coating measured with screw gauge was ca. 140 μm. The morphologies of uncoated and coated fertilizer granules analyzed by using scanning electron microscopy were changed from porosities and gullies to hills and plain. The release rate of coated compound fertilizers in water could be controlled by the hydrophicity and thickness of coating. The increase in coating hydrophicity caused the increase in release rate of fertilizer. The increase in thickness of coating slowed the release rate.

ADSORPTION BEHAVIOR OF PHENOLIC COMPOUNDS ONTO POLYMERIC ADSORBENTS MODIFIED WITH 2-CARBOXYBENZOYL GROUPS

Two hypercrosslinked polymeric adsorbents （ZH-01 and Amberlite XAD-4 resin） were employed to remove three kinds of phenolic compounds including phenol, 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions. The study was focused on the static equilibrium adsorption behavior, the column dynamic adsorption and desorption profiles. The Freundlich model gave a perfect fitting to the isotherm data. The adsorbing capacities for these three compounds on ZH-01 were higher than those on Amberlite XAD-4 within the temperature range 288-318 K, which was attributed to the large micropore area and 2-carboxybenzoyl functional groups on the network of ZH-01 resin. The adsorption for phenol and 4- nitrophenol on ZH-01 was a physical adsorption process, while for 2,4-dinitrophenol it was a coexistence process of physical adsorption and chemisorption＇s transitions. The column test showed the advantages of ZH-01 in the dynamic adsorption processes of phenolic compounds. Being used as the desorption reagent, sodium hydroxide solution showed an excellent performance.

Thermodynamic study of adsorption of phenolic compounds onto Amberlite XAD-4 polymeric adsorbents and its acetylized derivative MX-4

Adsorption equilibrium isotherms of phenolic compounds, phenol, p cresol, p chlorophenol and p nitrophenol, from aqueous solutions by Amberlite XAD 4 polymeric adsorbent and its acetylized derivative MX 4 within temperature range of 283 323K were obtained and fitted to the Freundlich isotherms. The capacities of equilibrium adsorption for all four phenolic compounds from their aqueous solutions increased around 20% on the acetylized resin, which may be contributed to the specific surface area and the partial polarity on the network. Estimations of the isosteric enthalpy, free energy, and entropy for the adsorption process were reported.

New Azomethine Compounds on the Basis <i>m</i>-Phenylenediamine and Substituted Benzaldehydes Capable of Oxidative Polymerization

Low-temperature condensation of m-phenylene diamine and various aromatic aldehydes (benzaldehyde, m-, o-nitrobenzaldehyde, p-diethylaminobenzaldehyde, o-, p-hydroxybenzaldehyde and 4-hydroxy-3,5-ditert-butylbenzaldehyde) in the ethyl alcohol medium synthesized new azomethine compounds. With the help of spectral methods and elemental analysis, the structure of the azomethine compounds obtained was confirmed. It was founded that irradiation of azomethine compounds with UV light at a wavelength of 300 - 330 nm results in their emission. The luminescent properties of the resulting compounds are due to the presence of chromophore azomethine groups in the molecule structure. In particular, the π-electrons of the azomethine bonds can undergo irradiation to a different energy levels, accompanied by fluorescence. It was shown that synthesized azomethine compounds are capable of oxidative polymerization. Based on azomethine compounds in hydrochloric acid solution synthesized polymers with conjugated bonds, which had low molecular-mass characteristics. It is shown that the oxidative polymerization of azomethines proceeds through a slow (one-electron transfer) and rapid (recombination of the radical cations) stage.

Examination of Polymeric Azomethine Compounds and Their Transition Metal Complexes by Using XRF and XRD Technique

In this study,the electronic transition properties and structural analysis of the metal complexes(Ni(Ⅱ),Co(Ⅱ),Cu(Ⅱ)and Mn(Ⅱ))of three different polymer ligands were performed by using XRF and X-ray diffraction(XRD)techniques,respectively.The structural analysis of the polymers and their complexes were performed by XRD technique and some of the polymers were found to be in the face-centred cubic(fcc)structure.In addition,the values of the present K X-ray intensity ratios are significantly greater than the values reported in literature.

Preparation of Polymeric Monolithic Column and Application to the Resolution of Aromatic Compounds in Capillary Electrochromatography

Polymeric monolithic capillary column-poly(GMA-co-EDMA-co-AMPS) was prepared andused for resolution of aromatic compounds (benzalcohol, 2-phenylethanol, toluene, ethylbenzene).

THERMODYNAMIC STUDY OF ADSORPTION OF PHENOLIC COMPOUNDS FROM AQUEOUS SOLUTION BY A WATER-COMPATIBLE HYPERCROSSLINKED POLYMERIC ADSORBENT

Equilibrium data for the adsorption of phenolic compounds, i.e., phenol, p-cresol, p-chlorophenol and p- nitrophenol from aqueous solutions by a water-compatible hypercrosslinked polymeric adsorbent (NJ-8) within temperature range of 283-323 K were obtained and correlated with a Freundlich-type of isotherm equation, so that equilibrium constants KF and n were obtained. The capacities of equilibrium adsorption for all the four phenolic compounds on the NJ-8 from aqueous solutions are around 2 times as high as those of Amberlite XAD-4, which may be attributed to the unusual micropore structure and the partial polarity on the network. The values of the enthalpy (always negative) are indicative of an exothermic process, which manifests the adsorption of all the four phenolic compounds on the two polymeric adsorbents to be a process of physical adsorption. The negative values of free energy change show that the solute is more concentrated on the adsorbent than in the bulk solution. The absolute free energy values of adsorption for NJ-8 are always higher than those for Amberlite XAD-4, which indicates that phenolic compounds are preferentially adsorbed on NJ-8. The negative values of the adsorption entropy are consistent with the restricted mobilities of adsorbed molecules of phenolic compounds as compared with the molecules in solution. The adsorption entropy values of phenolic compounds for NJ-8 are lower than those for Amberlite XAD-4, which means the micropores of NJ-8 require more orderly arranged adsorbate.

复合型内给电子体ID对MgCl_(2)/2-乙基己醇/TiCl_(4)催化体系催化乙烯聚合性能的影响

以MgCl_(2)/2-乙基己醇/TiCl_(4)体系合成用于乙烯聚合的球形Ziegler-Natta催化剂,在合成催化剂过程中加入复合内给电子体:乙酸正己酯/邻酞酸二异丁酯,与分别加入四乙氧基硅烷、乙酸乙酯和邻酞酸二异丁酯内给电子体的催化剂进行对比。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和差示扫描量热仪(DSC)等手段对含不同内给电子体的催化剂和聚合物进行分析,并通过乙烯聚合对催化剂催化性能进行评价。结果表明,在温度为80℃,压力0.5 MPa,时间2 h的条件下,含复合内给电子体乙酸正己酯/邻酞酸二异丁酯的催化剂催化乙烯聚合活性比其它单一内给电子体的催化剂催化活性要高,催化活性为1.24×10^(5)g PE/(mol_(Ti)·h)。

Molecular Dynamic Simulation on the Absorbing Process of Isolating and Coating of α-olefin Drag Reducing Polymer

The absorbing process in isolating and coating process of α-olefin drag reducing polymer was studied by molecular dynamic simulation method, on basis of coating theory of α-olefin drag reducing polymer particles with polyurethane as coating material. The distributions of sodium laurate, sodium dodeeyl sulfate, and sodium dodeeyl benzene sulfonate on the surface of α-olefin drag reducing polymer particles were almost the same, but the bending degrees of them were obviously different. The bending degree of SLA molecules was greater than those of the other two surfactant molecules. Simulation results of absorbing and accumulating structure showed that, though hydrophobie properties of surfactant molecules were almost the same, water density around long chain sulfonate sodium was bigger than that around alkyl sulfate sodium. This property goes against useful absorbing and accumulating on the surface of α-olefin drag reducing polymer particles; simulation results of interactions of different surfactant and multiple hydroxyl compounds on surface of particles showed that, interactions of different surfaetant and one kind of multiple hydroxyl compound were similar to those of one kind of surfaetant and different multiple hydroxyl compounds. These two contrast types of interactions also exhibited the differences of absorbing distribution and closing degrees to surface of particles. The sequence of closing degrees was derived from simulation; control step of addition polymerization interaction in coating process was absorbing mass transfer process, so the more closed to surface of particle the multiple hydroxyl compounds were, the easier interactions With isoeyanate were. Simulation results represented the compatibility relationship between surfactant and multiple hydroxyl compounds. The isolating and coating processes of α-olefin drag reducing polymer were further understood on molecule and atom level through above simulation research, and based on the simulation, a referenced theoretical basis was provided for practical optimal selection and experimental preparation of α-olefin drag reducing polymer particles suspension isolation agent.

无氟拒水剂成膜表面形貌及其拒水性能研究

为考察无氟拒水乳液的成膜形貌对拒水性能的影响,将细乳液聚合得到的聚丙烯酸十八酯-丙烯酸丁酯[P(SA-BA)]胶乳分别与四种粒径的聚丙烯酸十八酯/γ-甲基丙烯酰氧基丙基三甲氧基硅烷[P(SA-A174)]胶乳按比例共混后,采用涂覆和浸轧两种工艺整理玻璃片和面料,以SEM和AFM考察了整理得到的两种基材表面形貌,并考察了对拒水性的影响。结果表明:P(SA-BA)和P(SA-A174)分别具有成膜和保型能力,二者复合而成的胶乳可形成具有纳米“指突”形貌的拒水膜,使整理基材的拒水性能明显提升。随着P (SA-A174)粒径的增大和用量的提高,涂层整理膜的“指突”高度和面密度同时增加,而浸轧整理时,仅“指突”高度增加,面密度和拒水性能变化不大。之后,通过降低浸轧液pH值,胶乳对织物亲和力以及吸附效率增强,浸轧整理织物拒水性能明显提升。

共聚阻燃改性聚对苯二甲酸乙二醇酯的制备及其性能

针对聚对苯二甲酸乙二醇酯(PET)阻燃性较差的问题,以[(6-氧代-6H-二苯并[c,e][1,2]氧磷杂己环-6-基)甲基]丁二酸(DDP)和明胶基碳点(gCDs)构建复合阻燃体系,采用原位聚合法制备了阻燃DDP-gCDs-PET,借助扫描电子显微镜、傅里叶变换红外光谱仪对其结构进行分析,通过极限氧指数(LOI)、垂直燃烧(UL-94)及锥形量热指标研究了不同质量分数的gCDs与DDP复配后对PET阻燃性能的影响,并利用热重-傅里叶变换红外光谱分析探究了阻燃PET在气相中的热分解产物,提出了DDP、gCDs对PET的阻燃机制。结果表明:当添加DDP质量分数为8%、gCDs质量分数为1.0%时,DDP-gCDs-PET的UL-94等级提升至V-0级,LOI值可达到35%;相较于纯PET,DDP-gCDs-PET的热释放速率峰值降低39.77%,总热释放量降低25.00%,引燃时间延长25 s,阻燃效果显著改善;在燃烧过程中DDP促进了PET基体分解并在气相中淬灭自由基,gCDs使热量迅速扩散,提升了PET基体的热稳定性能,且gCDs在凝聚相促进成炭使DDP中的P留存于炭层中,二者共同作用提升了PET的阻燃性能。

微胶囊包埋技术在增强食品稳定性中的作用

食品稳定性的增强对于确保食品的安全性、保持其营养价值、增加经济效益至关重要。微胶囊包埋技术通过构建坚固的物理屏障,可有效隔离氧气和湿气等外界因素,同时抑制食品中微生物的生长;通过使用抗氧化的壁材,可减缓或阻止化学反应的发生,从而增强食品的化学稳定性;通过其独特的缓释机制,能够按需释放活性成分;通过抗酶作用,可防止食品中的酶与敏感成分直接接触。本文通过实际案例阐述了变性淀粉作为壁材,通过乳化和喷雾干燥工艺生产肉味复合调味料的微胶囊化过程,证明了微胶囊包埋技术在实际食品加工中提升产品稳定性的有效性。

双官能化溶聚丁苯橡胶在轮胎胎面胶中的应用

使用国产双端官能化产品SSBR2060-N和日本Zeon公司单端官能化产品Nipol■NS616进行成品轮胎试制及性能评价。结果表明,使用SSBR2060-N制备的成品轮胎外边缘尺寸达到技术标准,抗湿滑性能和滚动阻力均达到了欧洲议会和欧盟理事会联合颁布的轮胎标签法规EU2020/740规定的双B轮胎级别,强度性能、高速性能和耐久性能等均与使用Nipol■NS616制备的成品轮胎相当且均能够满足国家标准要求。

Synthesis of spherical CoAl_2O_4 pigment particles with high reflectivity by polymeric-aerosol pyrolysis

Spherical cobalt blue particles with good reflectivity characteristics were synthesized by spray pyrolysis. Two different spray solutions were prepared to investigate the differences in the morphology and the reflectivity properties of cobalt blue particles. One was an aqueous solution, and the other was a polycation solution that was obtained by chemically modifying the aqueous solution with NH4OH. The cobalt blue particles prepared with the aqueous solution had an irregular morphology after heat treatment at 1000~C for 2 h. On the contrary, spherical and dense particles were obtained from the polycation solution. The spherical and dense cobalt blue particles showed remarkable improvement in reflectivity compared with that of irregular morphology particles as well as the commercial.

Femtosecond laser fabrication of 3D templates for mass production of artificial compound eyes

Compound eyes are unique optical imaging systems that consist of numerous separate light-sensitive units(ommatidia).Attempts have been made to produce artificial compound eyes via advanced 3 D nanotechnologies.Among them,femtosecond laser direct writing(FsLDW)technology has emerged as an effective strategy due to its distinct advantages in 3 D designable and high precision fabrication capability.However,the point-by-point scanning process results in a very low fabrication efficiency,limiting the practical applications of the FsLDW technology.To solve this problem,we propose a high-efficiency method for the mass production of 3 D artificial compound eyes using a photopolymer template fabricated by FsLDW.The resultant 3 D SU-8 compound eye templates could be used to replicate polydimethylsiloxane(PDMS)compound eyes many times(over 50 times)with a highly improved efficiency(nearly 20 times higher than the efficiency of direct fabrication using the point-by-point FsLDW).The PDMS replicas showed good focusing and imaging performances.We anticipate that this method may serve as an enabler for the mass production of 3 D artificial compound eyes and promote their practical applications in the near future.

Syntheses, Crystal Structures, and Magnetic Properties of Mn(Ⅱ) and Co(Ⅱ) Coordination Polymers Constructed from Pyridine-tricarboxylate Ligand

Two coordination polymers, namely {[Mn（HL_1）（phen）]·4H_2O}_n（1） and [Co_2（HL_2）_2（H_2O）_2]_n（2） have been constructed hydrothermally using H_3L_1 and H_3L_2（H_3L_1 = 2-（5-carboxypyridin-2-yl）terephthalic acid, H_3L_2 = 2-（4-carboxypyridin-3-yl）terephthalic acid）, phen, MnCl_2×4H_2O and CoCl_2×6H_2O. The products were isolated as stable crystalline solids and were characterized by IR spectroscopy, elemental, thermogravimetric（TGA）, powder（PXRD） and single-crystal X-ray diffraction analyses. Compound 1 features a 3D framework structure, which was topologically classified as a trinodal 4,6,6-connected net with the unique topology defined by the point symbol of（3^（10）.5.6~4）4（3^（10）.6.7~4）2（5.6~2.8~2.9）. Compound 2 possesses a 2D metal-organic layer, which was topologically classified as a binodal 4,4-connected layer defined by the point symbol of（4~3.6~2.8）. The layers are further extended into a 3D supramolecular framework via hydrogen bonds. The magnetic properties for both compounds were also investigated, indicating antiferromagnetic interactions between the adjacent metal ions.

Composite bilayer films with organic compound-triggered bending properties

Organic compounds are widely used in both industry and daily life,and composite bilayer films with organic compound-triggered bending properties are promising for applications of transducers,soft robotics,and so on.Here,a universal and straightforward strategy to generate composite bilayer films with organic compoundtriggered bending properties is demonstrated.The composite bilayer films with organic compound-triggered bending properties are designed with bilayer structures,in which one layer is a porous polymeric membrane with appropriate solubility parameter that matches the value of organic solvents in order to produce prominent affinity to the solvent molecules,and the other layer is reduced graphene oxide membrane stacked on the porous polymeric membrane as an inert layer for restraining the swelling of the polymeric membrane on one side.Guided by matching the solubility parameters between solvent and polymer,a significant bending curvature of 27.3 cm-1 is obtained in acetone vapor.The results in this study will provide valuable guidance for designing and developing functional composite materials with significant organic compound-triggered bending properties.

SYNTHESIS OF ORGANOGERMANE OLIGOMERS VIA LIGAND SUBSTITUTION POLYMERIZATION FROM 1, 4-DIOXANE COMPLEX OF GERMANIUM DICHLORIDE

Some organogermanium oligomers with different side groups were synthesized via ligand substitution polymerization from I, l-dioxane complex of germanium dichloride with different organolithium compounds. The oligomers were isolated through either precipitation from methanol or extraction using toluene with a yield of no less than 50%. The weight average molecular weight (M-w) of the oligomers is ranging from 1.4 x 10(3) to 5.9 x 10(3) depending on the type and alkyl length of the organolithium compounds used.