Biological oyster shell waste enhances polyphenylene sulfide composites and endows them with antibacterial properties

To date,there is no research that deals with biological waste as fillers in polyphenylene sulfide(PPS).In this study,oyster shells were recycled and treated to prepare thermally-treated oyster shells(TOS),which were used as PPS fillers to make new bio-based antibacterial composite materials.The effect of varying the content of TOS was studied by means of structure and performance characterization.PPS/TOS composites were demonstrated to have an antibacterial effect on the growth of E coli and S.aureus.Qualitative analysis showed that when the TOS content was≥30%and 40%,the composite materials had an apparent inhibition zone.Quantitative analysis showed that the antibacterial activity increased with the TOS content.Fourier transform infrared spectroscopy indicated the formation of hydrogen bonds between the molecular chains of TOS and PPS and the occurrence of a coordination reaction.At 10%TOS,the composite tensile strength reached a maximum value of 72.5 MPa,which is 9.65%higher than that of pure PPS.The trend of bending properties is the same as that of tensile properties,showing that the maximum property was reached for the composite with 10%TOS.At the same time,the crystallinity and contact angle were the highest,and the permeability coefficient was the lowest.The fatigue test results indicated that for the composite with 10%TOS,the tensile strength was 23%lower than static tensile strength,and the yield strength was 10%lower than the static yield strength.The results of the study showed that TOS not only could reduce the cost of PPS,but also could impart antibacterial properties and enhance the mechanical and,barrier properties,the thermostability,as well as the crystallinity.

RHEOLOGICAL BEHAVIOR OF POLYPHENYLENE SULFIDE/POLYAMIDE-66 BLENDS

Blends of polyphenylene sulfide (PPS) containing trace amounts of branching and/or cross-linking in chain and Polyamide-66 (PA-66) have been prepared by melt blending. The rheological behavior of PPS/PA-66 blends has been studied by means of capillary rheometer, and compared with PPS. The effects of shear rate, shear stress and temperature on the how of PPS/PA-66 blends and PPS are discussed. The non-Newtonian indexes and the activation energies of viscous how are obtained. The results show that the apparent viscosity of PPS/PA-66 blends is not sensitive to shear rate and stress, but decreases with the elevation of temperature. On the contrary, the apparent viscosity of the PPS decreases obviously with the increasing of shear rate and shear stress, but it is increased by the elevation of temperature.

A New Way of Strengthening and Toughening for Carbon Fiber Reinforced Polyphenylene Sulfide(CF/PPS) Composites via Matrix Modification

The effect of pressure-induced flow（PIF） processing on the mechanical properties of noncontinuous carbon fiber（CF） reinforced polyphenylene sulfide（PPS） composites was investigated. A series of CF/PPS composites under different processing conditions were prepared through PIF-processing. SEM observations showed that the interfaces adhesion between CFs and PPS became stronger and ductile fracture mainly occurred in PPS matrix. This brought to a great increase of both strength and toughness by about 2 folds, when the composites were processed at 240 ℃ and under 263 MPa. The results in differential scanning calorimetry（DSC） and X-ray diffraction（XRD） measurements indicated more regular crystalline structures and orientation of lamellae formed during PIF-processing.

SYNTHESES AND CHARACTERIZATIONS OF HYPERBRANCHED POLYPHENYLENES

New hyperbranched polyphenylenes with high molecular weights are synthesized by the copolycyclotrimerizations of 1,4-diethynylbenzene (I) with phenylacetylene (A), 1-octyne (B), and 1-dodecyne (C) catalyzed by TaCl5-Ph4Sn. The polymers are completely soluble in common solvents such as toluene, THF, chloroform, and dichloromethane. The polymers are characterized by spectroscopic methods and all of the polymers give satisfactory analysis data corresponding to their expected molecular structures.

Bonding strength of graded anti-corrosive coatings of fluoroethylenepropylene (FEP)/polyphenylene sulfide (PPS)

Fluororesin-based anti-corrosive coatings including graded FEP/PPS were prepared on carbon steel by melt powder coating, the bonding strength of all coating systems was determined by the pull-off test. It is found that the poor adhesion of fluororesin coatings to metallic substrates is improved obviously by the graded coating structure of FEP/PPS, and the bonding strength reaches up to 11.8 MPa for the five-layer system. Examination by electron probe microanalysis （EPMA） verifies that the distribution of main components is graded in the five-layer system, which is responsible for the enhancement of the interfacial bonding.

SYNTHESIS AND CHARACTERIZATION OF SOLUBLE POLYPHENYLENE COMPOSED OF p-PHENYLENE AND m-PHENYLENE UNITS

NiCl2(bpy) catalyzed polycondensation between p-dibromobenzene and m-dibromobenzene has been carried out under various conditions. The polycondensation endows the copolymer with an M-n of 2300 (by GPC, polystyrene standards) and good solubility in organic solvents. The fluorescence spectra of the copolymer measured with tetrahydrofuran solution shows an emission maximum (lambda(max)) at 372.8 nm, whereas for the film the maximum shifts to 436.6 nm.

Conductive and stable polyphenylene/CNT composite membrane for electrically enhanced membrane fouling mitigation

Nanocarbon-based conductive membranes, especially carbon nanotube (CNT)-based membranes, have tremendous potential for wastewater treatment and water purification because of their excellent water permeability and selectivity, as well as their electrochemically enhanced performance (e.g., improved antifouling ability). However, it remains challenging to prepare CNT membranes with high structural stability and high electrical conductivity. In this study, a highly electroconductive and structurally stable polyphenylene/CNT (PP/CNT) composite membrane was prepared by electropolymerizing biphenyl on a CNT hollow fiber membrane. The PP/CNT membrane showed 3.4 and 5.0 times higher electrical conductivity than pure CNT and poly(vinyl alcohol)/CNT (PVA/CNT) membranes, respectively. The structural stability of the membrane was superior to that of the pure CNT membrane and comparable to that of the PVA/CNT membrane. The membrane fouling was significantly alleviated under an electrical assistance of −2.0 V, with a flux loss of only 11.7% after 5 h filtration of humic acid, which is significantly lower than those of PP/CNT membranes without electro-assistance (56.8%) and commercial polyvinylidene fluoride (PVDF) membranes (64.1%). Additionally, the rejection of negatively charged pollutants (humic acid and sodium alginate) was improved by the enhanced electrostatic repulsion. After four consecutive filtration-cleaning cycle tests, the flux recovery rate after backwashing reached 97.2%, which was much higher than those of electricity-free PP/CNT membranes (67.0%) and commercial PVDF membranes (61.1%). This study offers insights into the preparation of stable conductive membranes for membrane fouling control in potential water treatment applications.

Polyphenylene sulfide based anion exchange fiber:Synthesis,characterization and adsorption of Cr(VI)

A fibrous strong base anion exchanger （QAPPS） was prepared for the first time via chloromethylation and quaternary amination reaction of polyphenylene sulfide fiber （PPS）, and its physical-chemical structure and adsorption behavior for Cr（VI） were characterized by FT- IR, Energy Dispersive Spectrometry, TG-DTG, elemental analysis and batch adsorptive technique, respectively. The novel fibrous adsorbent could effectively adsorb Cr（VI） over the pH range 1-12, the maximum adsorption capacity was 166.39 mg/g at pH 3.5, and the adsorption behavior could be described well by Langmuir isotherm equation model. The adsorption kinetics was studied using pseudo first-order and pseudo second-order models, and the 4/2 and equilibrium adsorption time were 5 and 20 min respectively when initial Cr（VI） concentration was 100 mg/L. The saturated fibers could be regenerated rapidly by a mixed solution of 0.5 mol/L NaOH and 0.5 mol/L NaCl, and the adsorption capacity was well maintained after six adsorption-desorption cycles.

Preparation and characterization of polyphenylene sulfide-based chelating fibers

A series of novel chelating fibers containing sulfur, nitrogen, oxygen heteroatoms were prepared via the functionalization of chloromethylated polyphenylene sulfide （CMPPS）. The structures, micromorpholo- gy and physicochemical properties of these fibrous adsorptive materials were characterized by FT-IR, elementary analysis, TG and SEM-EDS. The results show that chelating fibers had high functional group contents （3.94 mmol/g for thiourea, 3.85 mmol/g for mercapto, 5.00 mmol/g for methylamine and 6.07 mmol/g for ethylenediamine, respectively）. Owing to the unique matrix of polyphenylene sulfide fiber, these fibrous adsorbents possess excellent thermostability. This synthetic method proved a simple and efficient way for the preparation of chelating fibers.

Paper‑like Polyphenylene Sulfide/Aramid Fiber Electrode with Excellent Areal Capacitance and Flame‑Retardant Performance

In this paper,an aramid chopped fiber,so-called(ACF)/polyphenylene sulfide(PPS)composite,containing multi-walled carbon nanotubes(MWCNT),and in situ polymerized polypyrrole(PPy)was designed and fabricated,to be applied as a paper based electrode.The ACF/PPS/MWCNT-PPy electrode features highly porous paper-like structure with excel-lent electrochemical activity,rendering it a high areal capacitance of~3205 mF cm^(-2) at a current density of 5 mA cm^(-2).After 5000 charge-discharge cycles,the areal capacitance still maintains 93%and 70%at high current densities of 20 and 80 mA cm^(-2),respectively.Moreover,the ACF/PPS/MWCNT-PPy electrode displays over 50%the areal capacitance and maintains it's mechanical stability after annealing at 300℃.The UL-94 test reveals that the highest V-0 flame-retardant performance can be achieved.All these results suggest that the ACF/PPS/MWCNT-PPy composite is a promising material to be used as electrode for supercapacitor with high energy-storage capability and noninflammability.

Synthesis of Polyphenylenes through Bergman Cyclization of Enediynes with Long Chain Alkyl Groups

Several new enediynes with long chain alkyl groups were synthesized through Sonogashira coupling reactions between long chain alkynes and（Z）-1,2-dichloroethene. These enediynes（1） were then subjected to thermal Bergman cyclization in a refluxing diphenyl ether bath under vacuum to obtain conjugated polyphenylenes with the weight-average molecular weights up to 4.9 × 103 g·mol·1. The occurrence of Bergman cyclization was confirmed by 1H-NMR, 13C-NMR, and IR spectroscopic analysis. These polyphenylenes are fully soluble in common organic solvents and exhibit good thermal stability. The optical properties of the polyphenylenes were investigated by UV-Vis absorption and photoluminescence（PL） spectroscopies. A blue emission was observed for all these polyphenylenes.

Synthesis of Chiral Polyphenylenes through Bergman Cyclization of Enediynes with Pendant Chiral Amino Ester Groups

Chiral enediynes with pendant chiral amino ester groups are synthesized through Sonogashira reactions and subjected to thermal triggered Bergman cyclization at elevated temperatures either in bulk or in solvents to produce chiral polyphenylenes. The disappearance of enediyne monomers are evidenced by FTIR and NMR spectroscopies. The formation of polyphenylenes is further confirmed by UV-Vis and MALDI-TOF mass spectroscopies（MS）. Isotope pattern analysis of the MS spectra shows that the polymers prepared in solvents are terminated by the solvent molecules, whereas the chain ends of the polymers prepared in bulk consist of considerable amount of unmasked free radicals, which is further confirmed by EPR analysis. Circular dichroism（CD） spectra of the chiral polymers show blue shifts of the Cotton peaks, indicating the occurrence of the cycloaromatization reaction. A new set of peaks mirrored at the horizontal axis show up in the long wavelength range, which are assigned to main chain chirality of the polyphenylenes.

Simultaneously enhanced heat dissipation and tribological properties of polyphenylene sulfide-based composites via constructing segregated network structure

Self-lubricating polyphenylene sulfide(PPS)composites were fabricated by constructing a segregated network structure using the co-deposition method.Both carboxyl-functionalized multi-walled carbon nanotubes(CNTs)and silicon carbide(SiC)were successfully coated on the surface of PPS powders with the aid of self-polymerization of dopamine(PDA)and co-polymerization between PDA and polyethyleneimine(PEI),thereby forming PPS@PDA-CNTs-SiC hierarchical reinforcing hybrids.Results showed that the thermal conductivity of PPS@PDA-CNTs-SiC(0.97 W/(m K))is about 120%higher than that of PPS/CNTs/SiC.The friction coefficient(0.193)and specific wear rate(2.50×10^(-5)mm^(3)/(N m))of PPS@PDA-CNTs-SiC are 18.9%and 50%lower than those of PPS/CNTs/SiC,respectively.The enhanced thermal conductivity of PPS@PDA-CNTs-SiC contributes to rapid dissipation of frictional heat at the sliding interface which protects the polymer substrate from being destroyed or peeled,thereby improving the tribological performance.This work provides new insights into expanding the application of self-lubricating polymer composites in the fields where efficient heat dissipation is also a primary concern.

Synthesis of Conjugated Polyphenylene Dendritic β-Diketones

An efficient synthesis of high generation conjugated polyphenylene dendrimer-based β-diketones was investi- gated using simple synthetic methods. The new dendrimer-based β-diketones were characterized by NMR, MS and elemental analysis. The UV-Vis and fluorescence spectra of these β-diketones in different solvents were investigated The photoluminescent （PL） quantum yield and TG and DSC curves were also investigated. A new intermediate, 1-bromo-3,5-diiodobenzene, was developed to synthesize high generation dendrimers with good yields.

Interface-induced topological phase and doping-modulated bandgap of two-dimensioanl graphene-like networks

Biphenylene is a new topological material that has attracted much attention recently.By amplifying its size of unit cell,we construct a series of planar structures as homogeneous carbon allotropes in the form of polyphenylene networks.We first use the low-energy effective model to prove the topological three periodicity for these allotropes.Then,through first-principles calculations,we show that the topological phase has the Dirac point.As the size of per unit cell increases,the influence of the quaternary rings decreases,leading to a reduction in the anisotropy of the system,and the Dirac cone undergoes a transition from type II to type I.We confirm that there are two kinds of non-trivial topological phases with gapless and gapped bulk dispersion.Furthermore,we add a built-in electric field to the gapless system by doping with B and N atoms,which opens a gap for the bulk dispersion.Finally,by manipulating the built-in electric field,the dispersion relations of the edge modes will be transformed into a linear type.These findings provide a hopeful approach for designing the topological carbon-based materials with controllable properties of edge states.

The Development of Thermal Conductive Polymer Composites for Heat Sink

The thermal and mechanical properties of the polyamide 6/boron nitride and polyphenylene sulfide/graphite composites have been investigated as a function of composition and size of fillers. The addition of highly thermal conductive h-BN and graphite gives rise to large increase （about 2 times） of thermal conductivity of individual polymer. In PPS/graphite system, the higher conductivity value was obtained when smaller graphites were added. Meanwhile, the tensile and flexural strength are reduced upon increasing filler loading.

A NEW POLYMERIC FLAME RETARDANT ADDITIVE FOR NYLON

The present paper deals with the use of a new polymeric flame retardant material, polyphenylene sulphide (PPS) for plastics. Incorporation of 15—20% PPS into nylon-6 has provided UL V-0 rating for the system and there is enhancement in tensile and flexural properties. The results obtained on the thermal, crystallization and flow characteristics of the nylon-PPS system upto a loading of 40% PPS are also discussed.

Oxidative coupling polymerization of p-alkoxyphenols with Mn(acac)2-ethylenediamine catalysts

The oxidative coupling polymerization of p alkoxyphenols with Mn(acac)2ethylenediamine catalysts was carried out. The polymerization of pmethoxyphenol with the manganese(II) acetylacetonate [Mn(acac)2]N,N’diethylethylene diamine catalyst in CH2Cl2 at room temperature under an O2 atmosphere afforded a polymer, which mainly consists of the mphenylene unit, whereas the polymer obtained with Mn(acac)2 was rich in the oxyphenylene structure. The polymer yield and regioselectivity were significantly affected by the monomer and catalyst structures. The former catalyst system was also used for the coupling reaction of 2methoxy 4methylphenol. The corresponding carboncar bon coupling product was isolated with a regioselectivity of 95%.

Facile and effective synthesis strategy for terbium-doped hydroxyapatite toward photoelectric devices and flexible functional fibers

As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.

Metal halide perovskite nanocrystals with enhanced photoluminescence and stability toward anti-counterfeiting highperformance flexible fibers

As a new type of light-collecting and luminescent material,all-inorganic cesium lead halide CsPbX_(3)(X=Cl,Br,I)perovskite nanocrystals(NCs)are expected to have a wide range of applications in the fields of photovoltaics,optoelectronics,and fluorescence anti-counterfeiting,etc.Therefore,improving the fluorescence performance and stability of CsPbX_(3)perovskite NCs to prompt their applications would promise both fundamental and practical significance for in-depth research in the field of halide perovskites.In this paper,we developed a modification strategy to introduce a halogen source,zinc bromide(ZnBr_(2))in hexane,to CsPbX_(3)perovskite that can be conducted under atmospheric conditions with reduced reaction cost and easier operation.The first work in this paper was to apply the modification strategy to CsPbI_(3)nanowires(NWs).Compared with the untreated NWs,the ZnBr_(2)/hexane modified CsPbI_(3)NWs exhibited better fluorescence properties.Subsequently,based on the study of perovskite NWs,we investigated perovskite nanocrystal-CsPbI_(3)nanorods(NRs)with different morphologies and sizes.It was found that the luminescence properties of nanorods(NRs)were superior.Later,we infiltrated the modified NRs into the aramid/polyphenylene sulfide(ACFs/PPS)composite paper yielded from our previous work to study its fluorescence performance for anti-counterfeiting.Their luminescence properties under ultraviolet light irradiation enable better performance in fluorescence anti-counterfeiting.The ZnBr_(2)/hexane modification strategy and the applications studied in this work will expand the scope of perovskite research,laying the foundation for the applications of fluorescent anti-counterfeiting,nano-photoelectric devices,and fluorescent composite materials.