Comprehensive Evaluation and Prediction of the Effectiveness of H2O2-assisted Na2CO3 Pretreatment of Corn Stover Using Multivariate Analysis

Xiaoyan Feng,Xuejin Xie,Yidong Zhang,Guang Yu,Chao Liu,Bin Li,Qiu Cui

2021,(2):1-15.DOI:10.12103/j.issn.2096-2355.2021.02.001

In this study, multivariate analysis methods, including a principal component analysis (PCA) and partial least square (PLS) analysis, were applied to reveal the inner relationship of the key variables in the process of H2O2-assisted Na2CO3 (HSC) pretreatment of corn stover. A total of 120 pretreatment experiments were implemented at the lab scale under different conditions by varying the particle size of the corn stover and process variables. The results showed that the Na2CO3 dosage and pretreatment temperature had a strong influence on lignin removal, whereas pulp refining instrument (PFI) refining and Na2CO3 dosage played positive roles in the final total sugar yield. Furthermore, it was found that pretreatment conditions had a more significant impact on the amelioration of pretreatment effectiveness compared with the properties of raw corn stover. In addition, a prediction of the effectiveness of the corn stover HSC pretreatment based on a PLS analysis was conducted for the first time, and the test results of the predictability based on additional pretreatment experiments proved that the developed PLS model achieved a good predictive performance (particularly for the final total sugar yield), indicating that the developed PLS model can be used to predict the effectiveness of HSC pretreatment. Therefore, multivariate analysis can be potentially used to monitor and control the pretreatment process in future large-scale biorefinery applications.

[Abstract] [PDF]

Highly Conductive Fractal-structured Silver Particles for Preparing Flexible Printed Circuits via Screen Printing

Sufeng Zhang,Chen Hua,Bin He,Yongwei Li,Qiusheng Zhou,Pengbing Chang,Xuxu Hu,Lina Liu

2021,(2):16-28.DOI:10.12103/j.issn.2096-2355.2021.02.002

Fractal-structured silver particles (FSSPs) are conductive materials with a micron-scale trunk and nanoscale branches, and are characterized with high electrical conductivity and high connectivity. In this study, FSSPs were added to an aqueous additive solution for synthesizing a conductive ink, which was used to prepare two types of printing electrodes via screen printing. The first type included two flexible printed electrodes (FPEs): an FPE on a polyethylene terephthalate (PET) film and an FPE on paper. The second one was a polydimethylsiloxane (PDMS)-embedded FPE. The PET-based FPE exhibited high electrochemical stability when its sheet resistance was 0.38 Ω/sq for a 50% (w/w) content of FSSPs in the prepared conductive ink. Moreover, the embedded FPE demonstrated excellent mechanical properties and high chemical stability. In addition, the embedded structure was endowed with stretchability, which is important for different devices, such as flexible biomedical sensors and flexible electronics.

[Abstract] [PDF]

Conversion of Bioethanol to Olefins over ZrO2 Catalyst

Meixiang Gao,Jiaqi Xiao

2021,(2):29-34.DOI:10.12103/j.issn.2096-2355.2021.02.003

Ethylene and 1,3-butadiene are important organic chemical raw materials. Petroleum hydrocarbon cracking is the most widely used method for ethylene fabrication worldwide. In this study, the use of a ZrO2 catalyst, which can be easily synthesized, for the efficient conversion of bioethanol to ethylene and 1,3-butadiene was analyzed. X-ray diffraction, transmission electron microscopy, temperature-programmed desorption, and Fourier-transform infrared spectroscopy analyses were used to evaluate the surface properties of ZrO2. The selectivity of ZrO2 toward ethylene and 1,3-butadiene was as high as 98.2%. Catalyst selectivity toward dehydration or dehydrogenation products depends on the nature of the weak acid-base catalytic sites, whereas high-strength base and intermediate-strength acid catalytic sites selectively yield ethylene.

[Abstract] [PDF]

A Review of Hydrophobic Nanocellulose and Its Applications

Jinglei Xie,Shijie Liu

2021,(2):35-42.DOI:10.12103/j.issn.2096-2355.2021.02.004

Nanocellulose is of great interest in various areas nowadays as a natural nanostructured biomaterial. However, in many applications, the high hydrophilicity due to a large number of hydroxyl groups is not desired. The hydrophobic modification of nanocellulose can thus increase its application. This work reviewed recent developments of methods for nanocellulose hydrophobic modification, through physical adsorption and chemical grafting. The applications of hydrophobic nanocellulose were also reviewed.

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Natural Polysaccharide: Modification and Application

Ting Chen,Ce Sun,Xiuzhi Tian,Xue Jiang,Meiyun Zhang

2021,(2):43-58.DOI:10.12103/j.issn.2096-2355.2021.02.005

Natural polysaccharides are synthetic macromolecules located in the cell wall and intracellular, intercellular, and secretory cells. These are essential components of life activities. Cellulose and its derivatives, chitosan, alginic acid, starch, and other natural polymer materials that exist in nature are polysaccharides. This article briefly reviews the structure and sources of several natural polysaccharides, focusing on the modification design strategies of polysaccharides such as graft polymerization, oxidation, etherification, and esterification on cellulose (mainly cellulose nanocrystals, CNC), chitosan (CTS), and other polysaccharides and derivatives in the fields of biomass energy, composite materials, wastewater treatment, and biomedicine. Based on the theory of modification and application of polysaccharides at the present stage, future research goals and modification strategy design are prospected.

[Abstract] [PDF]

Lignosulfonate and Its Derivatives for Oil-well Drilling: A Concise Review

Ping He,Lei Dai,Xinyu Li,Zongjian Yang,Feiguo Hua,Liang Li,Bing Wei

2021,(2):59-68.DOI:10.12103/j.issn.2096-2355.2021.02.006

Lignosulfonate, a byproduct of the pulp and paper industry, has been used in the oil-well drilling industry for a significant amount of time. Lignosulfonate and its derivatives serve different roles in the oil-well drilling industry because of their unique structures and properties. This review summarizes lignosulfonate and its derivatives, including lignosulfonate complexed with metal ions, lignosulfonate graft copolymers, lignosulfonate-tannin complexes, and other lignosulfonate-containing composites, in terms of their preparation, properties, and potential applications in oil-well drilling industry. It provides readers with a quick review of existing studies in this area and some inspirations for future studies pertaining to the utilization of lignosulfonate-based materials in the oil-well drilling industry.

[Abstract] [PDF]