Hyperbranched polymer hollow-fiber-composite membranes for pervaporation separation of aromatic/aliphatic hydrocarbon mixtures

The separation of aromatic/aliphatic hydrocarbon mixtures is crucial in the petrochemical industry.Pervaporation is regarded as a promising approach for the separation of aromatic compounds from alkanes. Developing membrane materials with efficient separation performance is still the main task since the membrane should provide chemical stability, high permeation flux, and selectivity. In this study, the hyperbranched polymer(HBP) was deposited on the outer surface of a polyvinylidene fluoride(PVDF)hollow-fiber ultrafiltration membrane by a facile dip-coating method. The dip-coating rate, HBP concentration, and thermal cross-linking temperature were regulated to optimize the membrane structure.The obtained HBP/PVDF hollow-fiber-composite membrane had a good separation performance for aromatic/aliphatic hydrocarbon mixtures. For the 50%/50%(mass) toluene/n-heptane mixture, the permeation flux of optimized composite membranes could reach 1766 g·m^(-2)·h^(-1), with a separation factor of 4.1 at 60℃. Therefore, the HBP/PVDF hollow-fiber-composite membrane has great application prospects in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures.

Rational design of new in situ reduction of Ni(II)catalytic system for low-cost and large-scale preparation of porous aromatic frameworks

Porous aromatic framework 1(PAF-1)is an extremely representative nanoporous organic framework owing to its high stability and exceptionally high surface area.Currently,the synthesis of PAF-1 is catalyzed by the Ni(COD)2/COD/bpy system,suffering from great instability and high cost.Herein,we developed an in situ reduction of the Ni(II)catalytic system to synthesize PAF-1 in low cost and high yield.The active Ni(0)species produced from the NiCl_(2)/bpy/NaI/Mg catalyst system can effectively catalyze homocoupling of tetrakis(4-bromophenyl)methane at the room temperature to form PAF-1 with high Brunauer-Emmett-Teller(BET)-specific surface area up to 4948 m^(2) g^(−1)(Langmuir surface area,6785 m2 g−1).The possible halogen exchange and dehalogenation coupling mechanisms for this new catalytic process in PAF's synthesis are discussed in detail.The efficiency and universality of this innovative catalyst system have also been demonstrated in other PAFs'synthesis.This work provides a cheap,facile,and efficient method for scalable synthesis of PAFs and explores their application for high-pressure storage of Xe and Kr.

Aromatic Multicarboxylate Ligands Tuned One-and Three-dimensional Zn(Ⅱ) Coordination Polymers Based on 3-(1H-pyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole

Two aromatic multicarboxylate ligands tuned Zn(Ⅱ) coordination polymers, namely, {[Zn0.5(H2L)(tp)0.5(H2O)]H2O}n(1) and {[Zn2(HL)(btc)(H2O)]H2O}n(2)(H2L = 3-(1 Hpyrazol-4-yl)-5-(pyridin-3-yl)-1,2,4-triazole, H2tp = terephthalic acid;H3 btc = 1,3,5-benzenetricarboxylic) have been synthesized. Their structures were characterized by single-crystal X-ray diffraction analysis, elemental analyses and infrared spectra. Compound 1 possesses a one-dimensional chain structure and is finally extended into a three-dimensional supramolecular architecture though hydrogen bonding interactions. Compound 2 shows a three-dimensional framework. Meanwhile, compounds 1 and 2 exhibit luminescent emission in the solid, and can be investigated as potential luminescent materials.

Efficient recovery of aromatic compounds from the wastewater of styrene monomer and propylene oxide co-production plant via hypercrosslinked aryl-rich starch-β-cyclodextrin polymeric sorbent

Adsorptive recovery of valuable components from industrial wastewater is highly desirable for avoiding resource wastage but remains a challenge.Herein,we develop an efficient continuous adsorption process for recovering aromatic compounds in wastewater from styrene monomer and propylene oxide coproduction(SMPO)plant.Based on our insight into the potential of bio-based porous materials for adsorption application,starch-graft-polystyrene(SPS)and aryl-modifiedβ-cyclodextrin(ACD)were prepared,and novel hypercrosslinked porous polymers combined SPS with ACD(HSPS-ACDs)were synthesized through external crosslinking approach.In a binary-component system,the best-performing one HSPS-ACD(H)with high ACD content and large specific surface area possessed superior capacities for the representative aromatic compounds,acetophenone(AP,2.81 mmol·g^(-1))and 1-phenylethanol(1-PE,1.35 mmol·g^(-1))compared with the previously reported materials.Further,the adsorption properties of aromatic compounds on HSPS-ACD(H)were investigated in batch mode.For practical application,continuous adsorption experiments were conducted in a HSPS-ACD(H)-packed fixed bed,where the target aromatic components in wastewater were effectively retained and further released by elution.Besides showing the reversible adsorption and efficient enrichment effect,the HSPS-ACD(H)-packed fixed bed also maintained great stability in multiple cycles.Moreover,quantum chemical calculations were performed to elucidate the potential mechanism of adsorption of AP and 1-PE onto HSPS-ACD(H).

THE EFFECT OF SUBSTITUENT ON THE THERMAL PROPERTIES OF POLYESTERS CONSISTING OF AROMATIC TYPE SCHIFF BASE MESOGENIC UNITS AND POLYMETHYLENE SPACERS

Polyesters consisting of substituted aromatic type Schiff base mesogenic unit andpolymethylene spacers were synthesized and their thermal transitions and liquid crystallineproperties were studied. The liquid crystalline behaviour has been characterized by differentialscanning calorimetry (DSC) and optical polarizing microscopy. Structural broadening bysubstitution of methoxy group in 2, 2' positions of the mesogenic core produce polymers withlower transition temperatures. Polymers synthesized from ortho and meta substituted phenylenediamine did not form a liquid crystal phase.

Two-dimensional Grid-type Zinc(Ⅱ) Coordination Polymer Constructed by a New Aromatic Carboxylate Ligand

A new aromatic carboxylate ligand,namely 5-（pyrrolidin-1-yl）-1,3-benzenedicar-boxylic acid（H2pybdc）,was synthesized and characterized by FT-IR and single-crystal X-ray diffraction analysis.It crystallizes in triclinic system,P1 space group with a = 10.05（5） ,b = 11.53（5）,c = 12.92（6） ,α = 112.11（6）°,β = 92.79（7）°,γ = 102.98（7）°,V = 1337.113,Z = 4,Mr = 253.25,Dc = 1.258 g.cm-3,μ = 0.099 mm-1,F（000） = 536,the final R = 0.0822 and wR = 0.2575 for 1893 observed reflections（I 2σ（I））.Based on it,a two-dimensional grid-type Zn（Ⅱ） coordina-tion polymer of {[Zn（pybdc）（bpy）（H2O）].2H2O.0.5CH3OH}n（1） was solvothermally synthesized,which crystallizes in triclinic,space group P1 with a = 10.218（5） ？,b = 11.176（5） ,c =11.350（5） ,α = 95.855（5）°,β = 94.248（5）°,γ = 101.421（5）°,V = 1257.9（2） 3,Z = 2,Mr = 524.84,Dc = 1.386 g.cm-3,μ = 1.024 mm-1,F（000） = 546,the final R = 0.0635 and wR = 0.1879 for 3913 observed reflections（I 2σ（I））.

Solution Processable Material Derived from Aromatic Triazole, Azomethine and Tris: Preparation and Hole-Buffering Application in Polymer Light-Emitting Diodes

This work presents the synthesis of a new hole-buffering material TAZS and its successful application in polymer light-emitting diodes to enhance device performance. The TAZS is composed of aromatic 1,2,4-triazolylcore linked with three trihydroxy tert-butyl terminals via azomethine linkages. The TAZS forms ashomogeneous film deposited by spin-coating process. The HOMO and LUMO levels of TAZS are -5.23 eV and -2.40 eV, respectively, as estimated from cyclic voltammogram. The current density results of hole-only and electron-only devices confirm strong hole-buffering capability of TAZS layer. Multilayer PLEDs with different thickness of TAZS (ITO/PEDOT: PSS/TAZS (x nm)/SY/ETL/LiF/Al) have been successfully fabricated, using spin-coating process to deposit hole-injecting PEDOT: PSS, TAZS, and emissive SY layers. The PLED with 16 nm TAZS reveals the optimal device performance, with maximum luminance and maximum current efficiency of 19,046 cd/m2 and 4.08 cd/A, respectively, surpassing those without TAZS as HBL (8484 cd/m2, 2.13 cd/A). The hole-buffering characteristic of TAZS contributes greatly to improved charges’ recombination ratio and enhanced emission efficiency.

SYNTHESIS OF AN EPOXY-TERMINATED HYPERBRANCHED AROMATIC POLYESTER

An epoxy-terminated hyperbranched aromatic polyester (P3) was synthesized from a hyperbranched aromatic polyester containing carboxylic acid end groups (P1), which was derived from the condensation polymerization of the AB(2) monomer, 5-acetoxyisophthalic acid. Polymer P1 was converted into the polymeric acid chloride by reaction with thionyl chloride. The acid chloride was reacted with ethanol and glycidol to form a poly(ethyl ester) (P2) and an epoxy terminated material (P3), respectively. The reaction conditions in each step of these processes had to be controlled very carefully to avoid unwanted cross-linking reactions. The characterization of products and intermediates, including molecular weight distributions and thermal properties, are reported.

Synthesis and characterization of new polyesters based on 2,5-bis[(4-chloro carboxyanilino)carbonyl]pyridine and aromatic diols

Six new polyesters 7a-f were synthesized through the solution polycondensation reaction of diacid chloride 5 with six aromatic diols 6a-f in N,N-dimethyl acetamide(DMAc) as solvent in the presence of pyridine as base.The polycondensation reaction produced a series of novel polyester containing pyridyl moiety in the main chain in high yields with inherent viscosities between 0.35 and 0.54 dL/g.The resulted polymers were fully characterized by means of FT-IR spectroscopy,elemental analyses,inherent viscosity ...

SYNTHESIS AND PROPERTIES OF POLY(AROMATIC DIACETYLENE)S CONTAINING FLUORENE

Novel fluorene-based poly(aromatic diacetylene)s have been synthesized by CuCl-catalyzed oxidative coupling of aromatic diynes.New aromatic diynes 2,7-diethynyl-9,9-bis(triphenylamine)fluorene(M_1)is synthesized by multistep reactions.The structures and properties of the polymers are characterized and evaluated by IR,NMR,TGA,UV, photoluminescence(PL),and cyclic voltammetry analyses.These polymers possess good thermal stability.All the polymers are completely soluble in coammon solvents such as toluene,THF,c...

STUDY OF MODIFIED AROMATIC POLYAMIDE SYNTHESIS AND CHARACTERISTICS OF CHLORINATED PPTA

Super pure 2,5-dichloroterephthaloyl dichloride (DDC) was prepared by chlorination andcontrolled by Gas Chromatography(GC) method. As a third monomer, DDC waspolycondensated into chlorinated PPTA together with terephthaloyldichloide (TPDC) andparaphenylene diamine (PPDA). The polycondensation conditions and the relationship betweenthe thermal behavior, viscosity, solubility, phase transition temperature of the modifiedpolyamide and the third monomer content discussed in this paper.

LAMELLAR STRUCTURE OF THERMOTROPIC LIQUID CRYSTALLINE POLYMERS

The lamellar structure of a thermotropic aromatic polyester with flexible spacer has beenstudied by using transmission electron microscopy. It was found that the lamellar structure couldbe observed in the crystalline samples of this semirigid polymer crystallized from different states.The thickness of lamellae is around 10 nm, which is similar to that of the conventional polymersof flexible chain molecules. The molecular chains in the lamellae are oriented in the thicknessdirection as determined by electron diffraction. The possibility of molecular chains folding in the lamellae has been discussed.

STUDIES ON THE REGULAR COPOLYMERS OF POLY (1, 4-PHENYLENETEREPHTHALAMIDE)

Two types of the regular copolymer of poly (1, 4-phenyleneterephthalamide) were synthesized by the low temperature solution polycondensation in NMP-CaCl_2 solvent system, using the piperazine or 2,5-dimethylpiperazine as the third components introduced in the main chain of poly (1, 4-phenyleneterephthalamide). The properties of copolymers were characterized by IR, SEM, X-RAY diffraction, polarizing microscopy, TGA and solubilities.Experimental results showed that the copolymers had good solubility and thermal stability, the concentrated sulfuric acid (～98% ) solution of regular PPTA copolymers had liquid crystalline proper-

SYNTHESIS AND CHARACTERIZATION OF MAIN CHAIN AROMATIC LIQUID CRYSTAL COPOLYESTERS WITH X-SHAPED AND ROD-SHAPED MESOGENIC UNITS

A series of main chain liquid crystal aromatic copolyesters with X-shaped and rod-shaped mesogenic units were synthesized via solution condensation polymerizations of 4,4'-(alpha,omega-octanedioyloxy)-dibenzoyl dichlorides with 2,5-bis(p-octanoxy benzoyloxy)-hydroquinone and diphenol. All of the copolyesters showed thermotropic liquid crystalline behaviors through observations using DSC, polarized microscopy and X-ray diffraction. The melting point (T-m) and the isotropization temperature (T-i) change regularly with varying the content of diphenol unit in the copolymers.

Nonlinear Optical Properties of Novel Polypyrrole Derivatives Bearing Different Aromatic Segments

Polypyrrole (PPy) and its derivatives containing different were synthesized by the interfacial polymerization reaction using ammonium per sulfate as oxidant, and were characterized by using Fourier transform infrared, Ultraviolet/visible absorption, and Raman spectroscopic techniques. The third-order nonlinear optical properties of all samples were measured by using nanosecond Z-scan measurements at 532 nm. At the identical mass concentration of 0.15 mg·mL-1, all PPy derivatives exhibited an obvious reverse saturable absorption performance, while the saturable absorption response was observed for PPy. In addition, significant differences in their nonlinear optical performances were observed, highlighting the influence on optical nonlinearity of the aromatic segments of conjugated polymers.

Quinoxaline-based Polymers with Asymmetric Aromatic Side Chain Enables 16.27% Efficiency for Organic Solar Cells

In recent years, due to the rapid development of high-performance small molecule acceptor (SMA) materials, the researches on p-type electron donor materials for matching with current efficient SMAs have become important. By means of asymmetric strategies to optimize the energy levels and inter/intramolecular interactions of molecules, we designed and synthesized an asymmetric aromatic side chain quinoxaline-based polymer donor TPQ-0F. Meanwhile, we took advantage of F atom which could form noncovalent interaction and strong electron-withdrawing property, to obtain the optimized quinoxaline-based polymer donors TPQ-1F, TPQ-1Fi and TPQ-2F. Eventually, the binary device based on TPQ-2F achieved an efficient power conversion efficiency (PCE) of 16.27%, which attributed to balanced hole/electron mobilities, less charge carrier recombination, and more favorable aggregation morphology. Our work demonstrates the great potential of asymmetric aromatic side chain quinoxaline-based polymer donors on optimizing the morphology of blending films, improving inter/intramolecular interactions, and subtly tuning energy level, finally for more efficient organic solar cells.

芳香性聚氨基酸破乳剂的制备及性能评价

以芳香族氨基酸苯丙氨酸为疏水单体、脂肪族氨基酸天冬氨酸为亲水单体,通过氨基酸N-羧基环内酸酐(NCA)单体的开环聚合(ROP),制备了一系列强极性、高芳香度的聚氨基酸类高分子破乳剂聚苯丙氨酸-聚天冬氨酸苄酯(PPA-b-PBAA),并对产物进行了结构表征和相对分子质量测定。采用瓶试法评价了PPA-b-PBAA的破乳性能,结果表明PPA-b-PBAA具有优秀的低温破乳效率,室温下2 min内能高效分离pH=6.0~11.0、含油量1.0%~10.0%(质量分数)的稀释沥青乳状液。其中,PPA-b-PBAA对1.0%(质量分数)的含油乳化废水的最佳脱水效率达到了99.98%,相应脱出水中残余油含量低至8.50 mg/L。破乳机理研究表明,PPA-b-PBAA加入油水乳状液后能快速迁移到达油水界面,通过与形成油水界面膜的沥青质、胶质相互作用,促使分散油滴絮凝聚并,实现油水分离。量子化学计算和弱相互作用分析表明,破乳剂PPA-b-PBAA分子与形成油水界面膜的主要成分沥青质之间产生的强相互作用有利于加速油水界面膜破裂和分散油滴聚并,是助推PPA-b-PBAA低温高效快速破乳脱水的关键。

基于柱芳烃与联吡啶构建多功能纳米胶囊

高分子胶囊有着优越的性质和功能,在食品安全、医药、催化等领域都有着重要的应用。共价自组装是近年来制备高分子胶囊的一种新方法,该方法通过构筑单元与连接链在溶液中一步横向交联形成结构规整的分子胶囊。共价自组装方法制备胶囊一个突出的优点是组分的功能性选择,多种排列组合的可能极大地拓展了高分子胶囊的应用范围。选用柱芳烃这种大环分子作为构筑基元,并在其侧面桥连亚甲基部位修饰溴,与带有联吡啶结构的氨基柔性链交联,构建了一种尺寸在500nm左右、集主客体响应和贵金属拓展性于一体的多功能纳米胶囊。

Self-assembly of supramolecular polymers in water from tetracationic and tetraanionic monomers in water through cooperative electrostatic attraction and aromatic stacking

The cooperative electrostatic attraction and π-π aromatic stacking interactions between tetrahedral tetrapyridinium TP and three tetraanionic tetraphenylethylene derivatives TPE-1～3 led to the formation of a new kind of supramolecular polymer networks in water, which have been confirmed by^1 H NMR,fluorescence, isothermal titration calorimetric(ITC) and dynamic light scattering(DLS) experiments. ITC studies show that the contributions of enthalpy and entropy were comparable, reflecting the importance of hydrophobicity in driving the intermolecular aromatic stacking. DLS experiments indicate that the linear supramolecular polymers formed by these tetratopic monomers further aggregated into networks of 10~2-nm size.

Aromatic Amide Polymers that Form Two Helical Conformations with Twist Sense Bias in Water

Two benzene/2,2＇-bipyridine-alternately incorporated amide polymers have been prepared, which are driven by hydrophobicity to form two different helical conformations. Both helices exhibit twist sense bias in water induced by chiral valine side chains and the coordination of the 2,2＇-bipyridine unit to the Ni2＋ ions.