Cellulose-based photocatalytic paper with Ag_(2)O nanoparticles loaded on graphite fibers

TiO_(2) nanoparticle is the most extensively used photocatalyst for photocatalytic paper.However,TiO_(2) nanoparticle is active only under UV light that accounted for less than 5%of the solar light energy.There is a need to develop a photocatalytic paper with full spectrum photoactivity.Herein,a full spectrum photocatalytic paper was fabricated by incorporating cellulose fibers with graphite fibers which were pre-loaded with Ag_(2)O nanoparticles.X-ray diffraction(XRD)testing and scanning electron microscopy(SEM)examination confirmed the loading of the Ag_(2)O nanoparticles onto the graphite fibers.The photocatalytic activity of the paper was evaluated with the degradation of methyl orange(MO)under ultraviolet,visible or near-infrared light irradiation.It was found that the degradation rate of MO could reach 32%,19%and 19%under UV,visible and NIR light,respectively after 3 h of irradiation.Meanwhile,the photocatalytic paper was very stable and can be reused repeatedly.Antibacterial tests showed that the photocatalytic paper could inhibit Escherichia coli(E.coli)growth under office lighting condition.

Piezoresistivity of Carbon Fiber Graphite Cement-based Composites with CCCW

The electrical conductivity and piezoresistivity of carbon fiber graphite cement-matrix composites（CFGCC） with carbon fiber content（1% by the weight of cement）,graphite powder contents （0%-50% by the weight of cement） and CCCW（cementitious capillary crystalline waterproofing materials,4% by the weight of cement） were studied.The experimental results showed that the relationship between the resistivity of CFGCC and the concentration of graphite powders had typical features of percolation phenomena.The percolation threshold was about 20%.A clear piezoresistive effect was observed in CFGCC with 1wt% of carbon fibers,20wt% or 30wt% of graphite powders under uniaxial compressive tests,indicating that this type of smart composites was a promising candidate for strain sensing.The measured gage factor （defined as the fractional change in resistance per unit strain） of CFGCC with graphite content of 20wt% and 30wt% were 37 and 22,respectively.With the addition of CCCW,the mechanical properties of CFGCC were improved,which benefited CFGCC piezoresistivity of stability.

One dimensional pea-shaped NiSe_(2) nanoparticles encapsulated in N-doped graphitic carbon fibers to boost redox reversibility in sodium-ion batteries

In recent years,sodium-ion batteries(SIBs)have emerged as a promising technology for energy storage systems(ESSs)because of the abundance and affordability of sodium.Recently,metal selenides have been studied as promising high-performance conversion-type anode materials in SIBs.Among them,nickel se-lenide(NiSe_(2))has received considerable attention due to its high theoretical capacity of 495 mAh g^(-1)and conductivity.However,it still suffers from poor cycling stability because of the low electrochemical reactivity,large volume expansion,and structural instability during cycles.To address these challenges,NiSe_(2)nanoparticles encapsulated in N-doped graphitic carbon fibers(NiSe_(2)@NGCF)were synthesized by using ZIF-8 as a template.NiSe_(2)@NGCF showed a high discharge capacity of 558.3 mAh g^(-1)with a fading rate of 0.14%per cycle after 200 cycles at 0.5 A g^(-1)in 0.01-3.0 V.At a very high current density of 5 A g^(-1),the capacity still displayed excellent long-term cycle life with a discharge capacity of 406.1 mAh g^(-1)with a fading rate of 0.016%per cycle after 3000 cycles.The mechanism of the excellent electrochem-ical performance of NiSe_(2)@NGCF was thoroughly investigated by ex-situ XRD,TEM,and SEM analyses.Furthermore,NiSe_(2)@NGCF//Na_(3)V_(2)(PO_(4))_(3)full-cell also delivered an excellent reversible capacity of 378.7 mAh g^(−1)at 0.1 A g^(−1)after 50 cycles,demonstrating its potential for practical application in SIBs.

STATIC AND FATIGUE BEHAVIOR OF IMPACTED AS4/PEEK THERMOPLASTIC COMPOSITES UNDER COMPRESSION LOAD

Static and fatigue tests under compression load were made on impacted AS4/PEEK and T300/913C graphite/epoxy with [45/90/-45/0]5S stacking sequence. The comparison of the damage tolerance assessment for thermosetting and thermoplastic composites shows that thermoplastics are more damage tolerant under compression. Impacted thermoplastic composites have excellent compression-compression fatigue behavior. The damage growth life is only a few percent of their total fatigue life and no regular damage growth can be found. Some design principles for thermosetting composite structures may still be used.

PTC/NTC Behavior of PVDF Composites Filled with GF and CF

Conductive polyvinylidene fluoride（PVDF）matrix composites filled with graphited fiber（GF）or carbon fiber（CF）were prepared by the melt-mixing method.The breakage and length distribution of the fibers in the polymer matrix were studied by scanning electron microscope（SEM）and optical microscope（OM）observations,respectively. The differences in the positive temperature coefficient（PTC）effects of the composites were mainly attributed to inter-fiber contact ability.The elimination of the negative temperature coefficient（NTC）effect for CF/PVDF composite was because of an increase in the viscosity of the polymer matrix.With the same filler content,CF could be more effective,to eliminate the NTC effect when compared with GF.Addition of 2%CF（mass fraction）in the PVDF composite with 7%GF（mass fraction）could effectively eliminate the NTC phenomenon of the composite.