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Liquid mulching film is an emerging film material to replace the traditional plastic film, which causes wide public concern. In this study, a graft copolymer (LS-AA) was synthesized from sodium lignosulfonate (LS) by free radical polymerization, which was added as enhancer to the cationic starch (CS) solutions to obtain the CLA based film. The grafting conditions was optimized by response surface methodology (RSM) for the preparation of LS-AA, after that the LS-AA was characterized by FTIR, XRD, and TG. The highest grafting rate was obtained under the reaction conditions of 80 °C for 2.6 h with the mass ratio of monomer and LS of 5.5/5 at initiator dosage of 1 %. The fabricated liquid mulching film with addition of LS-AA showed outstanding anti-ultraviolet, biodegradation, anti-erosion, which provided theoretical base and practical references for popularizing and application of liquid mulching film in the dust prevention and sand fixation.

ABSTRACTIn order to evaluate reservoir characteristics and gas potential of organic-rich shale in Bottom-Lower Cambrian Hetang Formation and Upper Ordovician Xinkailing Formation, Xiuwu Basin, Jiangxi Province, Lower Yangtze Plate of China, researches regarding reservoir characteristics of organic-rich shale thickness, moderate burial depth, abundance and maturity of organic matter, fracturability, organic-matter pores and absorption performance have been conducted to Hetang Formation and Xinkailing Formation through field survey, shallow drilling, analysis to hydrocarbon-generation potential, scanning electron microscopy, measuring specific surface area and isothermal adsorption experiments. The results show that (1) Hetang Formation reservoir, although with extremely rich material basis, is of unfavorable hydrocarbon generation conditions due to late-stage thermal maturity, besides of undeveloped micropore structure, reservoir space development mainly by macroscopic crack, so further exploration should focus on locating favorable areas of low maturity and developed cracks, which is considered distributing in the core of Yanshan-Lingangshan-Shiziyan Mountains syncline; (2) Xinkailing Formation reservoir is of better organic matter abundance, pore development and absorption performance than Xinkailing Formation and hence further exploration should focus on surveying favorable areas of better sedimentary facies belt and stable structure for major breakthrough in shale-gas exploration, which is considered distributing in Wuning-Lixi and Jinkou-Tuolin areas.

Composite films with oxidized carbon nanotubes (o-CNTs) incorporated in the chiral nematic liquid crystals (CNLCs) formed by cellulose nanocrystals (CNCs) were fabricated for the first time. Induced by solvent evaporation, the isotropic aqueous dispersion containing o-CNTs and CNCs gradually forms lyotropic CNLCs, and the framework of the CNLCs can be retained in the final solid films, confirmed by polarized optical microscopy observations and scanning electron microscopy observations. During this evaporation-induced self-assembly process, the predispersed o-CNTs were spontaneously integrated in the liquid crystal matrix. It is found that the incorporation of a trace amount of o-CNTs (∼1.5 wt %) can induce obvious structural changes of the films. The reflection spectrum shifts to higher wavelengths with increasing content of o-CNTs, resulting in a continuous increase of the helical pitch of the CNLC phase. Confined in the liquid crystal matrix, the randomly oriented o-CNTs in the aqueous dispersion are forced to adopt a higher degree of order. This ordered arrangement of o-CNTs combined with the intrinsic anisotropy of the CNLCs impart the composite film anisotropic conductivity as proved by the electrical resistance measurements. This new type of CNTs/CNCs composites could find applications in various fields such as sensors and photoelectronics.

Thehighly efficient utilization of lignin is of great importance for the development of the biorefinery industry. Herein, a novel “core–shell” lignin nanoparticle (LNP) with a diameter of around 135 nm was prepared, after the lignin was isolated from the effluent of formic acid fractionation via dialysis. In an attempt to endow composite materials with vital functionalities, the LNP was added to the starch film and the starch/polyvinyl alcohol (PVA) or starch/polyethylene oxide (PEO) composite film. The results showed that the hydrophobicity performance of the synthesized films was enhanced significantly. Specifically, the dynamic water contact angle value of the starch/PVA composite film with 1% (wt) addition of LNPs could be maintained as high as 122° for 180 s; the starch/PEO composite film also achieved an excellent water contact angle above 120°. The addition of LNPs promoted the formation of some rough structures on the film surface, as shown by the scanning electron microscopy images, which could repel the water molecules efficiently and are closely related to the enhanced hydrophobicity of the starch film. What is more, the as-prepared LNP conferred strengthened thermal stability and ultraviolet blocking properties on the starch composite film. The structural combination of the polymer film with LNPs holds the promise for providing advanced functionalities to the composite material with wide applications.

Biografting is a promising and ecofriendly approach to meet various application requirements of products. Herein, a popular green enzyme, laccase, was adopted to graft a hydrophobic phenolic compound (lauryl gallate, LG) onto chitosan (CTS). The resultant chitosan derivate (Lac/LG-CTS) was systematically analyzed by Fourier transform infrared (FTIR), grafting efficiency, scanning probe microscopy (SPM), and X-ray diffraction (XRD). This grafting technique produced a multifunctional chitosan copolymer with remarkably enhanced antioxidant property, hydrophobicity, and moisture barrier property. Furthermore, the swelling capacity and acid solubility of the copolymer film decreased significantly, although the tensile strength and elongation were slightly weakened as compared to those of native chitosan. These results suggest that the Lac/LG-CTS holds great potential as a food-packaging material, preservative agent, or edible coating material.