Compression molded composites were prepared through a water-assisted mixing of an aqueous suspension of poly(ethylene-co-acrylic acid), additive, and pulp fibers [thermomechanical pulp (TMP) or dissolving pulp (DP)]. The lubricating additives used were magnesium stearate (MgSt) and molybdenum disulphide (MoS 2 ). The composite materials had dry pulp contents ranging from 30 to 70 wt% and 5 wt% additive relative to the weight of the pulp. The adsorption of the additives onto the fibers was confirmed by scanning electron microscopy and energy dispersive X-ray analysis. DMA showed that MgSt and MoS 2 gave similar interphase properties for the TMP samples at all loading contents, but the combination of MgSt and MoS 2 improved the overall properties of the DP-based composites. The tensile modulus, at 70 wt% fiber content (TMP or DP), increased compared to the matrix by a factor of 6.3 and 8.1, without lubricants, and by a factor of 8 and 10.7, with lubricants, respectively. The increase in melt viscosity observed for the lubricated samples was greater for the TMP-based samples containing MoS 2 . At a lubricant content of 5 wt%, in 30 wt% TMP, the MoS 2 behaved as both a lubricant and compatibilizer.
The study presents
a more efficient way of exfoliating
MoS2 in water and the exfoliated MoS2 was used
in an
electrode. The electrodes were prepared from exfoliated MoS2 (active material)–nanocrystalline cellulose (binder) with
carbon nanotubes (electron-conducting support) and demonstrated in
a zinc battery half-cell that showed a Coulombic efficiency of 90%.
Successful exfoliation of MoS2 was done by sonication of
bulk MoS2 with sulfated cellulose nanocrystals (CNC) for
4 h. The exfoliation was confirmed by Raman and transmission electron
microscopy; interestingly, the Raman signals for exfoliated MoS2 show a blue shift for both A1g and E2g
1 bands, which
may be an indication of an induced lattice strain effect from the
CNC on MoS2. The resulting stable water suspension showed
no tendency of precipitation after 2 months of standing. The zeta
potential, ζ, for sodium sulfated CNC (CNC–OSO3Na)–MoS2 in water suspension was −45 mV,
whereas sulfated CNC (CNC–OSO3H)–MoS2 in water suspension had a zeta potential of −35 mV.
The sodium form of sulfated CNCs displayed micelle characteristics,
similar to sodium dodecyl sulfate (SDS), with a critical aggregation
concentration (CAC) of 1.1 wt %. At CAC, the CNCs efficiently exfoliated
MoS2, which is at a much lower concentration than has been
reported for synthetic surfactants like SDS and cetyl trimethyl ammonium
bromide.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.