A novel way for high value-added application of lignosulfonate: Producing lignosulfonate nanosheets/graphene ultrathin film electrodes for electrochemical capacitors.

In this paper, a novel way for high value-added application of lignosulfonate is presented. In this study, we use lignosulfonate nanosheets to fabricate a free-standing, binder-free, ultrathin and light-weight conductive film electrode via vacuum filtration method. The results show that LS is a promising candidate material for the preparation of electrochemical capacitor film electrode. It is worth mentioning that we use non-toxic, pollution-free aqueous solution (water) over organic solvents as the dispersion during the reductive graphene oxide (RGO) preparation process. The electrochemical measurements exhibit that the resistivity of lignosulfonate nanosheets/RGO (LNRGO) film electrode is 0.66 × 10-3 kΩ cm-1. The specific capacitance of the LNRGO film electrode is calculated to be 120 mF cm-2 at the current density of 0.2 mA cm-2, which is approximately 6.67 times larger than that of RGO-water film electrode.

Fabrication of a novel hemin-based monolithic column and its application in separation of protein from complex bio-matrix.

A novel polymer-based monolithic column was prepared via redox initiation system within the confines of a stainless steel column with 4.6mm i.d. In the processes, hemin and lauryl methacrylate were used as co-monomers; ethylene dimethacrylate as crosslinking agent; n-butyl alcohol, ethanediol, and N, N-dimethylformamide as tri-porogens; benzoyl peroxide and N, N-dimethyl aniline as redox initiation system. The resulting polymer-based monolithic columns were characterized by scanning electron microscopy, nitrogen adsorption-desorption instrument, and mercury intrusion porosimeter, respectively. The results illustrated that the improved monolith had relative uniform porous structure, good permeability, and low back pressure. Aromatic compounds were used to test the chromatographic behavior of the monolith, resulting in highest column efficiency of 19 880 plates per meter with reversed-phase mechanism. Furthermore, the homemade monolith was used as the stationary phase of high performance liquid chromatography to separate proteins from complex bio-matrix, including human plasma, egg white, and snailase. The results showed that the monolithic column occupied good separation ability with these complex bio-samples. Excellent specific character of the homemade hemin-based monolith was that it could simultaneously remove high-abundance proteins (including human serum albumin, immunoglobulin G, and human fibrinogen) from human plasma and separate other proteins to different fractions.

Preparation of a poly(styrene-co-DPHA-co-EDMA) monolith and its application for the separation of small molecules and biomacromolecules by HPLC.

A high performance liquid chromatography (HPLC) monolithic column was prepared by redox polymerization of styrene, dipentaerythritol hexaacrylate (DPHA) and ethylene glycol dimethacrylate (EDMA) in a porogen system of n-propanol/PEG400. The monolith was characterized by scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and the results indicated that the monolith had a stable and homogeneous structure. The porosity of the monolithic column was 75.86% and average pore diameter was 2.1µm. Several alkylbenzenes and anilines were used to evaluate the column performance in terms of hydrophobicity. Then the column was applied to separate small molecules including phytosterol and BSA tryptic digest. Finally, five standard proteins, egg white and plasma were separated respectively and high separation capacity of protein was obtained.

Hemicelluloses removal in autohydrolysis pretreatment enhances the subsequent alkali impregnation effectiveness of poplar sapwood.

This work is aimed at investigating the influence of changes in the content of hemicelluloses of the autohydrolyzed poplar sapwood on the subsequent alkali impregnation for chemi-mechanical pulping (CMP). An alkali impregnation process was conducted using the autohydrolyzed poplar sapwood with different content of hemicelluloses as raw materials. The results showed that both the amount of NaOH consumption and swelling degree of poplar sapwood increased with the removal of hemicelluloses, thus enhancing the alkali impregnation effectiveness. The hemicelluloses removal can also shorten the alkali impregnation time for the autohydrolyzed poplar sapwood to achieve the similar impregnation effectiveness of unautohydrolyzed poplar sapwood. All of these can be attributed to the fact that the hemicelluloses removal would result in the exposure of more free hydroxyl groups on the cellulose and an increase in the porosity of the fiber cell walls.