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.

STUDY ON UV CURABLE POWDER COATINGS BASED ON HYPERBRANCHED POLYMERS

By introducing semicrystalline moieties into hyperbranched molecular smictures three kinds of prepolymers of potential use as UV powder coatings were prepared and characterized.

Cinnamate-functionalized hyperbranched polymer as liquid crystal photo-alignment layer

In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization （LPP） method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal （LC） cells containing nematic liquid crystal （5CB）. The observation by polarized microscope showed that the H30-Ci blended with a linear polymer （BP-AN-Ci） photo-alignment layers could align LC molecules in a very uniform way.

Hyperbranched Polymeric Fluorosurfactants:Synthesis,Surface Activity and Their Application in Firefighting Foams

Fluorosurfactants are the key ingredients in the formulations of aqueous film-forming foams(AFFFs)for extinguishing flammable liquids,thus developing high-efficient and low-toxic fluorosurfactants is desirable in AFFFs application.Herein,a series of hyperbranched polymeric fluorosu rfactants(HPFs)were successfully synthesized through sequentially modifying hyperbranched polyethylenimine(PEI)with the hydrophilic poly(ethylene glycol)(PEG)chains and the hydrophobic C6/C4-based perfluoroalkyl chains,which were verified by FTIR,^(1)H-and^(19)F-NMR.The surface tensions of all the HPFs in water were measured,and the corresponding physicochemical parameters were interpreted.It was found that the surface activities of HPFs could be tuned through adjusting the ratio of PEG to perfluoroalkyl chains,the length of perfluoroalkyl chains,the molecular weight of PEI core,but not the PEG chain length.In the binary mixture of HPFs with the commercial small molecule fluorosurfactant Capstone^(TM)1157(C1157),a strong synergism led to the elevation of surface activity,which was attributed to the efficient encapsulation of C1157 guests by the compact hyperbranched HPFs as the hosts.The utilization of HPF/C1157 as fluorosurfactant ingredients in AFFF formulations could realize much higher fire-extinguishing efficiency towards flammable oils than the control AFFFs prepa red from the polymeric Capstone^(TM)1460 or the neat C1157.

Carbon nanofibers membrane bridged with graphene nanosheet and hyperbranched polymer for high-performance osmotic energy harvesting

Reverse electrodialysis(RED),based on ion-selective membranes,is one of the most promising technologies for capturing osmotic energy.As key elements of the RED system,ion-selective membranes must meet the crucial demands of mechanical stability,anti-fouling characteristics,easy fabrication,and high power density;however,this still remains a challenge.In this study,we demonstrated a large-scale,mechanically stable,and high-porosity membrane obtained by combining carbon nanomaterials and hyperbranched polyethyleneimine(h-PEI),thereby achieving a high power density of 5.0 W·m−2 with seawater and river water.Carbon nanofibers(CNFs)were subsequently bridged with graphene and h-PEI to strengthen the interaction between the CNFs,reduce the channel size and increase the space charge density,mechanical strength,and toughness.The large-scale and mechanically stable membrane fabricated using the modified CNFs exhibited anion selectivity and high ionic conductivity,thereby achieving a high-performance osmotic energy conversion.Furthermore,the anti-fouling property of the membrane was confirmed by the stability of the osmotic energy conversion in a solution with algae,which can be attributed to the high porosity of carbon nanomaterials.This economic and convenient method for the ion-selective membrane preparation is believed to be promising for large-scale osmotic energy harvesting.

A New Method for Synthesizing Hyperbranched Polymers with Reductive Groups Using Redox/RAFT/SCVP

The novel hyperbranced polymers containing reductive groups were successfully prepared and characterized using redox/reversible addition fragmentation chain transfer （RAFT）/self-condensing vinyl polymerization （SCVP） method. Several redox initiating chemicals such as Cu（III）/--CONH2, Ce（IV）/--CONH2 and Ce（IV）/--OH were chosen to increase the free radical generating rate, and the chain transfer agent （CTA） was used to reduce the molecular chain propagating rate, in order to obtain polymers with high degree of branching. Detailed analyses based on the molecular weight, α value and the degree of branching of polymers （DB） obtained from 1H-NMR spectra and multi detector size exclusion chromatography （MDSEC） suggested the acquiring of hyperbranced polyacrylamides with Cu（III）/--CONH2 and Ce（IV）/--CONH2 as initiator in the presence of the CTA. Meanwhile, the as-prepared poly（N-hydroxymethyl acrylamide） （PNHAM） with higher DB value （0.48） proved that using Ce（IV）/--OH as the initiator could increase the free radical generating rate and diminish the gap between the propagating rate and the initiation rate during the reaction procedure. In addition, the effect of oxidant concentration on the Mark-Houwink index （α） value and the DB was also studied.

SECOND-ORDER NONLINEAR OPTICAL HYPERBRANCHED POLYMER CONTAINING ISOLATION CHROMOPHORE MOIETIES DERIVED FROM BOTH “H”-TYPE AND STAR-TYPE CHROMOPHORES

An NLO hyperbranched polymer （HP1） derived from both ＂H＂-type and star-type chromophores was synthesized successfully for the first time with high yield via one-pot ＂A2 ＋ B3＂ Suzuki polymerization reaction. Isolation chromophore was also introduced to further improve its performance. Although under the test conditions, the films of HP1 could not be poled completely, it still demonstrated satisfactory macroscopic NLO effect with the second harmonic generation （SHG） coefficient d33 value of 36 pm/V.

A FUNCTIONAL CONJUGATED HYPERBRANCHED POLYMER DERIVED FROM TETRAPHENYLETHENE AND OXADIAZOLE MOIETIES:SYNTHESIS BY ONE-POT “A_4+B_2+C_2” POLYMERIZATION AND APPLICAION AS EXPLOSIVE CHEMOSENSOR AND PLED

A new conjugated hyperbranched polymer （hb-TFO） containing tetraphenylethylene （TPE） units, a famous aggregation-induced emission （AIE） active group, as the core, was synthesized successfully with modest yield via one-pot Suzuki polymerization reaction. Thanks to the introduction of TPE moieties, hb-TFO exhibited aggregation-enhanced emission （AEE） property, and could work as explosive chemosensor with high sensitivity. The polymeric light-emitting diode （PLED） device was fabricated to investigate its electroluminescent property, and hb-TFO demonstrated a maximum luminance efficiency of 0.22 cd/A and a maximum brightness of 545 cd/m2 at 15.9 V.

A hyperbranched polymer-based water-resistant adhesive:Durable underwater adhesion and primer for anchoring anti-fouling hydrogel coating

Direct deployment of gluing and achieving durable robust adhesion in water is challenging due to difficulty in repelling interface water.This work reports a novel hyperbranched polymer-based water-resistant adhesive(HBPBA)based on Michael addition reaction of multi-vinyl monomers with dopamine and 3-aminophenylboronic acid.Upon encountering water,the HBPBA forms coacervates whose hydrophobic chains aggregate to displace interface water,and meanwhile the catechols exposing outwards contribute to underwater adhesion.The HBPBA can strongly glue diverse substrates including PTFE,PE,PET,ceramic,Ti and stainless steel.The HBPBA can maintain stable adhesion in different environments,such as tap water,simulated sea water,PBS,and a wide range of pH solutions(pH 2 to 10)for 3 months,supposedly due to the complexation of catechol with boronic acid.Intriguingly,HBPBA film can be bonded to the titanium surface as a primer,which firmly anchors the antifouling PNAGAPCBAA hydrogel coating through copolymerization of remaining double bonds in HBPBA and NAGA plus CBAA.The PNAGA-PCBAA hydrogel-modified titanium is biocompatible and shows outstanding antifouling ability both in vitro and in vivo.This work proposes a new strategy for creating underwater deployable and water-resistant adhesives that may find promising applications in engineering and biomedical fields.

Novel Hyperbranched Polymers as Host Materials for Green Thermally Activated Delayed Fluorescence OLEDs

A series of novel hyperbranched polymers （HBPs） consisting ofa 2,7-subsituted 9-（heptadecan-9-yl）-9H-carbazole unit （A2＋A2＇） and a tetra-substituted green thermally activated delayed fluorescence （TADF） dye of 2,3,5,6-tetra（9H- carbazol-9-yl）-4-pyridinecarbonitrile （4CzCNPy, B4） have been synthesized via Suzuki cross-coupling reaction following an ＂Az＋A2＇＋B4＂ method. The polymers are named according to the polymerization ratio of 4CzCNPy monomer （5 mol%, 10 mol% and 15 mol% for HBPs of P2-P4 respectively, and 0 mol% for the control linear polymer P1）. Their thermal, optoelectronic and electrochemical properties have been characterized by a combination of techniques. All the polymers exhibit high thermal stability with the decomposition temperatures （Ta） above 400 ℃ and glass transition temperatures （Tg） up to 98℃. Unfortunately, the incorporation of TADF moiety into these HBP materials induced non-TADF characteristics. However, when the HBPs functionalized as the host for our previously developed 4CzCNPy TADF dopant in solution processed devices, maximum external quantum efficiency of 5.7% and current efficiency of 17.9 cd/A have been achieved in P3-based device, which is significantly higher than those of 1.5% and 4.2 cd/A for the linear polymer P1.

Hyperbranched polymer micelles with triple-stimuli backbone-breakable iminoboronate ester linkages

Hyperbranched polymers have attracted increasing interests due to their unique structure-related advantages and have been utilized as drug carriers for controlled delivery.However,it is still challenging to prepare multi stimuli-responsive hyperbranched polymers to sense and response the complex yet delicate changes in physiological environment.Herein,we propose a triple-stimuli backbone-breakable hyperbranched polymer(HBP(OEG-IB)),which is prepared via the convenient iminoboronate multicomponent reaction ofα,ω-di(1,2-diol)s oligo(ethylene glycol),tris(3-aminopropyl)amine and 2-formylphenylboronic acid.Upon the stimulation of CO2,lactic acid and glutathione,micelles formed by HBP(OEG-IB)could be disrupted via the dissociation of iminoboronate ester bond to subsequent release incorporated camptothecin(CPT).Cell experiments show that the HBP(OEG-IB)is non-toxic but can enhance the therapeutic effect of CPT thanks to the effect of the protonated tertiary amino groups.The demonstration made in this work can enrich the design of responsive HBPs and can be readily applied to other systems with tunable responsive properties and functions.

Synthesis and characterization of dendronized hyperbranched polymers through the “A_3+B_2” approach

Dendronized hyperbranched polymer(DHP) is a new kind of polymer, which combines the advantages of dendrimers and hyperbranched polymers. In this work, two dendronized hyperbranched polymers, DHPG0 and DHPG1, were successfully prepared through the simple "A_3+B_2" type Sonogashira coupling reaction. The nonlinear optical(NLO) effects of DHPG0 and DHPG1, characterized by the d33 values, were 183 and 220 pm V^(–1) respectively, higher than those of their analogues of dendronized polymers and dendrimers, thanks to the special topological structure. Also, the obtained polymers displayed excellent solubility, good processability, and high thermal stability.

SYNTHESIS AND MAGNETIC PROPERTIES OF COMPLEXES OF A CONJUGATED HYPERBRANCHED POLYMER CONTAINING BITHIAZOLE RINGS

A novel conjugated hyperbranched polymer containing bithiazole rings （PBTADB） was synthesized by polycondensation of 1,3,5-benzenetricarboxaldehyde and 2,2＇-diamino-4,4＇-bithiazole （DABT）. The structure of the hyperbranched polymer was confirmed by FT-IR and 1H-NMR. PBTADB dissolved in organic polar solvents such as DMSO and NMP. Bithiazole tings were introduced to provide bidentate N-donor sites for binding metal ions. The metal complexes were prepared by chelation of the polymer with Co2＋ and Sm3＋. The magnetic behavior of coolcdination compounds was measured as a function of magnetic field strength （0-4.8 ×106 A/m） at 5 K and as a fimetion of temperature （5-300 K） at magnetic field strength of 2.4×106 A/re. The magnetic hysteresis loops of PBTADB-Sm3＋ and PBTADB-Co2＋ showed the typical ＇S＇ shape at 5 K with the Curie-Weiss temperature To = 96 K and 41 K respectively. The results show that they exhibit properties of soft ferromagnetic materials.

Amphiphilic hyperbranched polymers:synthesis,characterization and selfassembly performance

A series of amphiphilic hyperbranched polymers(AHP-s,the“s”refers to the algebra of AHP)were synthesized by the reaction between hydroxyl-terminated hyperbranched polymers(HBP-s,the“s”refers to the algebra of HBP)and palmitoyl chloride.FTIR,NMR and GPC were used to determine the structure of AHP-s,the results showed that AHP-s exhibits core-shell structure.The thermal properties of polymers were investigated by DSC and TGA.It was found that AHP-2,AHP-3 and AHP-4 display higher thermal stability than AHP-1(AHP-1,AHP-2,AHP-3 and AHP-4 represent the first,second,third and fourth generation AHP,respectively).Furthermore,the self-assembly performance of AHP-s in THF solvent was investigated by TEM and SEM.Finally,the encapsulation capacity of the AHP-s for methyl orange(MO)was explored at different concentrations of AHP-s and pH conditions.It was found that AHP-s is capable of accommodating hydrophilic guest MO.Moreover,the higher generation of AHP-s,the stronger encapsulation capacity obtained.And the encapsulation capacity closely associated with the pH of encapsulation system.

Enhancing the long-term Na-storage cyclability of conversion-type iron selenide composite by construction of 3D inherited hyperbranched polymer buffering matrix

Electrochemical conversion reactions provide more selections for Na-storage materials, but the reaction suffers from low reversibility and poor cyclability. Introducing an electrochemically inactive component is a common strategy, but the effect is quite limited since it could not stabilize the structure during long-term cycling. In this study, a new approach is developed using an amino group-functioned hyperbranched polymer (AHP) as a template and electrode additive for the design of high-performance FeSe2-AHP composite with chemical interaction. The assembled FeSe2-AHP composite nanoneedles were prepared by the selenylation of FeS-AHP composite microflowers and entirely inherit the polymer network from the precursor. The amino groups of AHP in composite coordinate with iron cations to achieve uniform polymer dispersion in the composite, and maintain the molecular level mixed state during the long-term cycling. Moreover, the in-situ constructed uniform 3D elastic polymer network effectively accommodates volume expansion and alleviates nanoparticle aggregation during sodiation/de-sodiation. FeSe2-AHP composite provides a superior rate capability (584.8 mAh·g−1 at 20 A·g−1) and a remarkable cyclability with a capacity retention rate of 93.3% after 2,000 cycles. FeSe2-AHP composite shows a high pseudocapacitive behavior for the abundant nanometer interface established by AHP, enhancing the solid-state Na+ diffusion. The FeSe2-AHP anode is also compatible with Na3V2(PO4)3/C cathode in a full Na-ion battery, which provides a high-power performance (powering 51 LEDs). The work herein highlights an innovative and efficient strategy for conversion-type material design and demonstrates the function of chemical interaction of polymer additive in the enhancement of long-term cyclability for conversion electrode.

Fluorescent traceable nanoparticles by co-self-assembly of carbon dot-drug conjugate and biodegradable hyperbranched polymer for diagnosis and therapy

Carbon dots(CDs)have attracted more interest in tumor theranostics,but they suffer from the rapid renal clearance due to small size and high hydrophilicity.To solve such problems,hydrophobic pH-triggered carbon dot-drug conjugate(CDs-Hy-DOX)with high doxorubicin(DOX)content of 48.23%were designed by covalent conjugation of DOX onto the CDs via acid-labile linkage with hydrazine(Hy)as bridge.Then the fluorescent traceable hybrid prodrug nanoparticles were fabricated via co-self-assembly with the CDs-Hy-DOX as pH-sensitive prodrug and a pH/reduction dual-triggered degradable hyperbranched polymer PEG-PO-Cy as polyethylene glycol(PEG)-based surfactant,as well as gatekeeper for pH/reduction dual-triggered DOX release.The hybrid prodrug nanoparticles with hydrodynamic diameter of 220 nm and DOX content of 22.99%were obtained with the optimized co-self-assembling condition.They could release 68.98%of DOX in the simulated tumor microenvironment within 3 days in a sustained release mode,with a premature drug leakage of 7.58%.After the acid-triggered DOX release from the CDs-Hy-DOX,which was accelerated by the pH/reduction dual-triggered degradation of the hyperbranched polymer,the strong fluorescence of CDs-Hy was recovered,demonstrating the promising potential in future tumor nanotheranostics.

HYPERBRANCHED AROMATIC POLYMERS OBTAINED VIA SELF-CONDENSATION

Hyperbranched aromatic polymers were prepared by Friedel-Crafts reaction with Lewis acid, AlCl3 and ZnCl2, as the catalysts. In this work, hyperbranched polybenzyl (PB) and poly(methylene)naphthalene (PN) were synthesized and characterized by H-1-NMR and GPC. In addition, their florescence properties were measured with steady-state florescence spectra in THF and ethylene dichloride. The quantum yields of polybenzyl and poly(methylene)naphthalene in ethylene dichloride are much larger than those in THE.

DEGREE OF BRANCHING OF THE HYPERBRANCHED POLYMERS RESULTED FROM AB_2 POLYCONDENSATION WITH SUBSTITUTION EFFECT

The analytical expressions of the various structural units and the average degree of branching for the hyperbranched polymers resulted from AB2 polycondensation with substitution effect were derived by the kinetic mechanism. The reactivity difference between the 13 group in linear unit and that in terminal group has great effect on the molecular parameters of the products obtained. The concentration of terminal units has a maximum with the increase of the conversion of A groups （x）. The higher the reactivity ratio （r） of linear B group to branched one is, the later the maximum appears and the larger it is. The degree of branching of the hyperbranched polymers obtained is controllable by adjusting the parameters of r and x, which increases with increasing both x and r.

Convenient Synthesis and Enhanced Second-order Nonlinear Optical Property of a Novel Hyperbranched Polymer

A novel hyperbranched polymer （3） was prepared by copolymerization of tri-aldehyde moieties with azo chromophores having two active methelene groups, from ＂A2＋B3＂ approach based on simple Kneovenagel reaction. For comparison, its analogue linear polymer （5） was also synthesized. The two polymers are soluble in common organic solvents, and exhibit good thermal stability. Interestingly, the hyperbranched polymer demonstrates dramatically enhanced second-order nonlinear optical property with comparison to its linear analogue.

Synthesis and Properties of Photo-functional Hyperbranched Polymers

1 Results UV curing systems have been widely used in various industries such as coatings,printing inks,and photo-resists,because of their low volatile organic compound (VOC),excellent physical properties,and energy saving.Recently,these systems have also been applied to electronics and information technology fields such as display,CD,DVD,optical-fiber,and optical-device. In these curing systems,(meth)acrylate oligomers are mainly used due to their high photochemical reactivity. Recently,dendritic polyme...