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.

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.

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.

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.

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.

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.

The morphology and dynamic viscoelasticity for PPS/low-melting temperature glass hybrids prepared by melt blending

Polyphenylene sulfides（PPS） and low-melting temperature glasses（LMTG） were used to prepare a PPS/LMTG organicinorganic hybrid material by melt blending.The etched surfaces of the hybrids were observed by scanning electron microscope （SEM） and the images showed different dispersed phase morphologies compared to traditional filled composites,which maybe induced by shear.Advanced rheometric expanded system（ARES） was used to investigate the rheological behaviors of the hybrids and the results showed that the strain y dependence of dynamic storage modulus G＇ for the hybrids with high contents of LMTG did not appear Payne effect.

Density functional theory study on the effect of molecular chain length on NO_(2)oxidation of PPS oligomers

Molecular chain models of polyphenylene sulfide(PPS)with polymerization degrees ranging from 2 to 10 were constructed.The geometries of the models,representing various lengths of molecular chains,were optimized using density functional theory.Subsequently,the activation energies and electronic properties of the reactions were computed.The findings indicated that the geometrical parameters of the PPS molecular chain model,with a polymerization degree exceeding 6,closely resemble actual PPS filters.Furthermore,the fluctuation in Mulliken charge of S atoms did not exceed 0.6%,and the variation in Mayer bond order was more consistent.The investigation revealed that the C-S bond and C-H bond are weaker links in the molecular chain,susceptible to disruption under harsh conditions.Analysis of the oxidation reaction between NO_(2)and PPS revealed the formation of a chemical bond between O atom in NO_(2)and S atom in PPS,emphasizing the influence of the electronic properties of PPS on the reaction.The activation energy for polyphenylene sulfide oxidation,with a polymerization degree greater than 6,remained constant at approximately 143 kJ·mol^(-1).Employing a molecular model of polyphenylene sulfide with a polymerization degree of 7 enhances the precision and reduces the computational workload in studying the oxidation reaction mechanism of PPS subjected to NO_(2).Selecting the appropriate length of the PPS molecular chain is crucial for investigating damage caused by flue gas components in PPS filter media and advancing filter media development further.