To electrically control magnetic properties of material is promising toward spintronic applications, where the investigation of carrier doping effects on antiferromagnetic (AFM) materials remains challenging due to their zero net magnetization. In this work, the authors find electron doping dependent variation of magnetic orders of a 2D AFM insulator NiPS 3 , where doping concentration is tuned by intercalating various organic cations into the van der Waals gaps of NiPS 3 without introduction of defects and impurity phases. The doped NiPS 3 shows an AFM-ferrimagnetic (FIM) transition at a doping level of 0.2-0.5 electrons/cell and a FIM-AFM transition at a doping level of ≥0.6 electrons/cell. The authors propose that the found phenomenon is due to competition between Stoner exchange dominated inter-chain ferromagnetic order and super-exchange dominated AFM order at different doping level. The studies provide a viable way to exploit correlation between electronic structures and magnetic properties of 2D magnetic materials for realization of magnetoelectric effect.
A light-colored hydroxypropyl sulfonated alkali lignin (HSAL) was synthesized based on pine alkali lignin (AL) by grafted-sulfonation and crosslinking reaction processes. The reactions were evaluated by gel-permeation chromatography (GPC), infrared (IR) and proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy. The sulfonic group content and the molecular weight ( M w ) of HSAL significantly increased, while the phenolic hydroxyl groups diminished by around 80% compared to AL. The color of HSAL turned to light yellow compared to the dark brown color of AL, that is, it stained less the fiber. The dispersity, heat stability, and dye uptake of dye bath with HSAL was significantly improved compared to sodium lignosulfonate, sulfomethy lated AL, and dispersants of the naphthalene series.
Two biorefinery lignosulfonates (LSs),
Ca-LS-DF and Na-LS-LP, were, respectively, isolated from pilot-scale
sulfite-pretreated spent liquor of lodgepole pine and fermentation
residue of Douglas-fir harvest forest residue. The molecular weights
of Na-LS-LP and Ca-LS-DF were approximately 9 000 and 11 000
Da, respectively. The two LSs were applied as dispersant for graphite
in aqueous suspensions. The dispersion stability was evaluated by
a scanning electron microscope and Turbiscan Lab Expert. LS performance
in modifying graphite was better than that of a commercial dispersant
Reax-85A as indicated by the Turbiscan TSI values, zeta potential
of suspension particles, and SEM imaging. The practical importance
of this study lies in the fact that the pilot-scale sulfite pretreatments
that produced the two LSs also produced excellent bioethanol yields
at high titer without detoxification and washing, suggesting the LSs
are a true value-added coproduct for high yield biofuel production.
Enzymatic hydrolysis lignin (EHL), from straw bioethanol process, was activated using NaOH/urea aqueous solution under low temperature condition to enhance its sulfonation degree and dispersion property. The sulfonation degree of EHL increased by 62.60% after the activation of NaOH/urea aqueous solution at −10 °C for 12 h, which is resulted from the breakage of the hydrogen bonds and ether bonds in lignin−carbohydrate complexes (LCCs) and the removal of residual carbohydrate. The functional group content, 2D-HSQC, and AFM analysis indicated that the increase of phenolic groups and the weakened aggregation degree of EHL after the activation are in favor of the increase of activity sites and decrease of steric hindrance, which is beneficial to the enhancement of sulfomethylation reactivity. Owing to the enhancement of reactivity, the dispersion properties of sulfomethylated EHL on graphite suspension were significantly enhanced.
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.