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12 pages, 2333 KiB

Open AccessArticle

Preparation of Bacterial Cellulose/Ketjen Black-TiO₂ Composite Separator and Its Application in Lithium-Sulfur Batteries

by Ming Yan, Chuanshan Zhao and Xia Li

Polymers 2022, 14(24), 5559; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14245559 - 19 Dec 2022

Viewed by 1942

Abstract

Lithium-sulfur batteries (LSBs) have attracted extensive attention due to their high energy density and low cost. The separator is a key component of LSBs. An excellent LSBs separator requires not only good electrolyte wettability, but also high thermal stability, good tensile mechanical properties, [...] Read more.

Lithium-sulfur batteries (LSBs) have attracted extensive attention due to their high energy density and low cost. The separator is a key component of LSBs. An excellent LSBs separator requires not only good electrolyte wettability, but also high thermal stability, good tensile mechanical properties, green environmental protection potential and enough inhibition of shuttle effect. In this paper, composite separator Bacterial cellulose/Ketjen black-TiO₂ (BKT) was prepared by coating the green and environmentally friendly bacterial cellulose (BC) substrate with KB-TiO₂ material. BKT not only demonstrates higher electrolyte wettability, but also displays thermal stability and tensile resistance to enhance the safety of the battery. The high ratio of TiO₂ and KB on the BKT surface provides chemical and physical adsorption of lithium polysulfides (LiPSs), thereby inhibiting the shuttle effect and increasing the cycle life of LSBs. The secondary current collector formed by TiO₂ and KB can also reactivate the adsorbed LiPSs, further improving the capacity retention rate of the battery. Therefore, the LSBs assembled with the BKT separator exhibited an initial discharge capacity of 1180 mAh × g⁻¹ at a high current density of 0.5 C, and maintained a specific discharge capacity of 653 mAh × g⁻¹ after 100 cycles was achieved. Even at 2.0 mg × cm⁻² sulfur areal density and 0.1 C current density, the BKT separator based battery still has an initial discharge specific capacity of 1274 mAh × g⁻¹. In conclusion, BKT is a promising lithium-sulfur battery separator material. sulfur areal densities. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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13 pages, 6831 KiB

Open AccessArticle

Fabrication Mechanisms of Lignin Nanoparticles and Their Ultraviolet Protection Ability in PVA Composite Film

by Jiawei Zhang, Zhongjian Tian, Xingxiang Ji and Fengshan Zhang

Polymers 2022, 14(19), 4196; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14194196 - 06 Oct 2022

Cited by 10 | Viewed by 2407

Abstract

Lignin is an indispensable and essential compound present in plants. It is a renewable resource and a green alternative to traditional petroleum energy. The rational utilization of lignin can reduce the environmental damage caused by traditional industrial development. The preparation of lignin nanoparticles [...] Read more.

Lignin is an indispensable and essential compound present in plants. It is a renewable resource and a green alternative to traditional petroleum energy. The rational utilization of lignin can reduce the environmental damage caused by traditional industrial development. The preparation of lignin nanoparticles (LNPs) using the self-assembly method is one of the most favorable ways to achieve high value-added utilization of lignin. However, the process requires an in-depth understanding of the sphere-forming mechanism of lignin self-assembly and the interaction of self-assembly forces. We used the same raw materials and two different preparation methods to prepare LNPs. The results revealed that the variation in the order of the dropwise addition of lignin solution and deionized water produced LNPs with varying average sizes. The sphere-forming mechanisms of the two kinds of lignin nanoparticles were discussed for the preparation of UV-resistant polyvinyl alcohol (PVA) polymeric films. During lignin spherification, the faster the solution reaches the supersaturation state, the faster the spherogenesis rate is, the smaller the size is, and the narrower the particle size distribution is. The lignin micro/nanospheres are produced by exploiting the π–π bonding interactions in lignin itself. The lignin micro/nanospheres are then mixed with PVA to form a film to obtain a lignin–PVA composite film material with an anti-UV effect. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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13 pages, 2647 KiB

Open AccessArticle

N-Doped Biochar from Lignocellulosic Biomass for Preparation of Adsorbent: Characterization, Kinetics and Application

by Jing Li, Fanxun Lv, Ran Yang, Liping Zhang, Wei Tao, Guotao Liu, Hui Gao and Ying Guan

Polymers 2022, 14(18), 3889; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14183889 - 17 Sep 2022

Cited by 10 | Viewed by 1930

Abstract

Medulla tetrapanacis is composed of a lignocellulosic biopolymer and has a regular porous structure, which makes it a potential biomass material for preparing porous N-doped biochar. Herewith, N-doped Medulla tetrapanacis biochar (UBC) was successfully prepared by modification with urea and NaHCO₃ under [...] Read more.

Medulla tetrapanacis is composed of a lignocellulosic biopolymer and has a regular porous structure, which makes it a potential biomass material for preparing porous N-doped biochar. Herewith, N-doped Medulla tetrapanacis biochar (UBC) was successfully prepared by modification with urea and NaHCO₃ under pyrolysis at 700 °C. The nitrogen-containing groups were efficiently introduced into biochar, and the micro-pore structures of the UBC were developed with sizeable specific surface area, which was loaded with massive adsorption sites. The adsorption kinetics and isotherms of the UBC conformed to pseudo-second-order and Langmuir model. The superior adsorption capacities of the UBC for methylene blue (MB) and congo red (CR) were 923.0 mg/g and 728.0 mg/g, and the capacities for Cu²⁺ and Pb²⁺ were 468.5 mg/g and 1466.5 mg/g, respectively. Moreover, the UBC had a stronger affinity for Cr³⁺ and Fe³⁺ in multiple metal ions and retained at a preferable adsorption performance for dyes and heavy metals after five cycles. Precipitation, complexation, and physical adsorption were the main mechanisms of the UBC-adsorbing metal ions and dyes. Thus, lignocellulosic biochar has great potential for removing dyes and heavy metals in aqueous solutions. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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15 pages, 4215 KiB

Open AccessArticle

Preparation and Application of In-Situ Loaded Silver Nanoparticles Antibacterial Fresh-Keeping Composite Paper

by Guangzhi Lin, Xia Li and Chuanshan Zhao

Polymers 2022, 14(18), 3798; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14183798 - 11 Sep 2022

Cited by 1 | Viewed by 1972

Abstract

The freshness and safety of fruits and vegetables affect our daily life. Paper products are often used in the packaging and transportation of fruits and vegetables, and these can provide other functions besides packaging after certain modifications and additions. In this study, the [...] Read more.

The freshness and safety of fruits and vegetables affect our daily life. Paper products are often used in the packaging and transportation of fruits and vegetables, and these can provide other functions besides packaging after certain modifications and additions. In this study, the AgNPs/1-MCP antibacterial fresh-keeping composite paper was prepared by in-situ loaded silver nanoparticles and spraying 1-MCP solution. Moreover, the prepared paper was used to preserve sweet cherries. It was found that the prepared AgNPs/1-MCP antibacterial fresh-keeping composite paper could effectively inhibit E. coli and S. aureus. When the addition of 1-MCP in the paper was 0.05 g, the fresh-keeping effect on cherries was the best. Under this optimal condition, the weight loss ratio of the cherries was reduced by 1.93%, the firmness was increased by 27.7%, and the soluble solid content was increased by 25%. The preservation time was extended from 4 days to 12 days, three times that of the untreated ones. The prepared fresh-keeping material is environmentally friendly, non-toxic and harmless, simple to prepare and convenient to use, and is expected to become one of the important fresh-keeping methods for fruits. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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17 pages, 3314 KiB

Open AccessArticle

2D Zinc-Based Metal–Organic Complexes Derived N-Doped Porous Carbon Nanosheets as Durable Air Cathode for Rechargeable Zn–Air Batteries

by Peng Jia, Jiawei Zhang, Guangmei Xia, Zhenjiang Yu, Jiazhen Sun and Xingxiang Ji

Polymers 2022, 14(13), 2581; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14132581 - 25 Jun 2022

Cited by 3 | Viewed by 1430

Abstract

The defect and N-doping engineering are critical to developing the highly efficient metal-free electrocatalysts for oxygen reduction reaction (ORR), mainly because they can efficiently regulate the geometric/electronic structures and sur-/interface properties of the carbon matrix. Herein, we provide a facile and scalable strategy [...] Read more.

The defect and N-doping engineering are critical to developing the highly efficient metal-free electrocatalysts for oxygen reduction reaction (ORR), mainly because they can efficiently regulate the geometric/electronic structures and sur-/interface properties of the carbon matrix. Herein, we provide a facile and scalable strategy for the large-scale synthesis of N-doped porous carbon nanosheets (NPCNs) with hierarchical pore structure, only involving solvothermal and pyrolysis processes. Additionally, the turnover frequency of ORR (TOF_ORR) was calculated by taking into account the electron-transfer number (n). Benefiting from the trimodal pore structures, high specific surface area, a higher pore volume, high-ratio mesopores, massive vacancies/long-range structural defects, and high-content pyridinic-N (~2.1%), the NPCNs-1000 shows an excellent ORR activity (1600 rpm, j_s = ~5.99 mA cm⁻²), a selectivity to four-electron ORR (~100%) and a superior stability in both the three-electrode tests (CP test for 7500 s at 0.8 V, Δj_s = ~0.58 mA cm⁻²) and Zn–Air battery (a negligible loss of 0.08 V within 265 h). Besides, the experimental results indicate that the enhancement of ORR activity mainly originates from the defects and pyridinic-N. More significantly, this work is expected to realize green and efficient energy storage and conversion along with the carbon peaking and carbon neutrality goals. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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15 pages, 4904 KiB

Open AccessArticle

Eco-Friendly and Complete Recycling of Waste Bamboo-Based Disposable Paper Cups for Value-Added Transparent Cellulose-Based Films and Paper Plastic Composites

by Peng Jia, Xiaoqian Ji, Bin Zheng, Chunyang Wang, Wenjie Hao, Wenjia Han, Jun Zhang, Guangmei Xia, Xingxiang Ji and Jinming Zhang

Polymers 2022, 14(8), 1589; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14081589 - 13 Apr 2022

Cited by 16 | Viewed by 5171

Abstract

Disposable paper cups are widely used in daily life and most of them are landfilled or incinerated after use, resulting in a serious ecological hazard and significant waste of resources due to the usage of thin polyethylene (PE) as their inner coating. Hence, [...] Read more.

Disposable paper cups are widely used in daily life and most of them are landfilled or incinerated after use, resulting in a serious ecological hazard and significant waste of resources due to the usage of thin polyethylene (PE) as their inner coating. Hence, converting these common solid domestic wastes into high-value added materials is attractive and meaningful. In this study, transparent cellulose-based films were achieved from old bamboo-based disposable paper cups after pretreatment through using the room ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as solvent. The cellulose-based film with a dense texture demonstrated a relatively nice mechanical and UV-shielding performances, and its tensile strength was as high as 48 MPa, much higher than that of commercial polyethylene (PE, 12 MPa) film. Thus, the resultant cellulose-based film showed a great potential in the packaging field. Besides, the flexible paper plastic composites (PPC) were also fabricated from the rest thin PE coating with the stuck fibers, and it was found that PPC showed excellent mechanical property and hydrophobicity. Consequently, a feasible and eco-friendly process of recycling and reusing waste disposable paper cups was developed to achieve a complete utilization and valorization of waste disposable paper cups. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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13 pages, 3435 KiB

Open AccessEditor’s ChoiceArticle

One-Pot Green Preparation of Fluorescent Cellulose Nanofibers

by Qilin Lu, Jiayin Wu, Hanchen Wang and Biao Huang

Polymers 2022, 14(7), 1313; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14071313 - 24 Mar 2022

Cited by 4 | Viewed by 2228

Abstract

Fluorescent cellulose nanofibers (FCNFs), with a high yield, were prepared via one-pot hydrolysis and the grafting reaction of cellulose with thiazolipyridine carboxylic acid (TPCA). The hydrolysis and Fischer esterification of cellulose were conducted under microwave-hydrothermal conditions; meanwhile, TPCA formation was induced by the [...] Read more.

Fluorescent cellulose nanofibers (FCNFs), with a high yield, were prepared via one-pot hydrolysis and the grafting reaction of cellulose with thiazolipyridine carboxylic acid (TPCA). The hydrolysis and Fischer esterification of cellulose were conducted under microwave-hydrothermal conditions; meanwhile, TPCA formation was induced by the dehydration reaction between L-cysteine and citric acid. The effects of the reaction temperature and reaction time on the yield and performance of FCNF were investigated. The morphology and size, surface chemical property, crystal structure, thermostability, and fluorescent performance of FCNF were characterized. The results revealed that the yield of FCNF reached 73.2% under a microwave power of 500 W, reaction temperature of 110 °C, and reaction time of 5 h. The FCNF obtained presents a short rod-like morphology. The crystallinity of the FCNFs is 80%, and their thermal stability did not decline significantly. Additionally, the fluorescent performance of the FCNFs is excellent, which results in them having good sensitivity to chloride ions. The good fluorescent performance and significant responsiveness to chloride ions of FCNFs lead to them having broad prospects in bio-labeling, biosensing, information storage, chloride ion detection, among others. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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Review

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27 pages, 7005 KiB

Open AccessReview

Recent Advances in Cellulose-Based Hydrogels for Tissue Engineering Applications

by Chao Chen, Yuewei Xi and Yunxuan Weng

Polymers 2022, 14(16), 3335; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14163335 - 16 Aug 2022

Cited by 36 | Viewed by 4873

Abstract

In recent years, cellulose has attracted much attention because of its excellent properties, such as its hydrophilicity, mechanical properties, biodegradability, biocompatibility, low cost and low toxicity. In addition, cellulose and its derivatives contain abundant hydrophilic functional groups (such as hydroxyl, carboxyl and aldehyde [...] Read more.

In recent years, cellulose has attracted much attention because of its excellent properties, such as its hydrophilicity, mechanical properties, biodegradability, biocompatibility, low cost and low toxicity. In addition, cellulose and its derivatives contain abundant hydrophilic functional groups (such as hydroxyl, carboxyl and aldehyde groups), which are good raw materials for synthesizing biocompatible hydrogels. In this paper, the application prospects of cellulose and its derivatives-based hydrogels in biomedical tissue engineering are summarized and discussed through the analysis of recent research. Firstly, we discuss the structure and properties of cellulose, nano celluloses (NC) from different sources (including cellulose nanocrystals (CNC), cellulose nanofibrils (CNF) and bacterial nano celluloses (BNC)) and cellulose derivatives (including cellulose ethers and cellulose esters) obtained by different modification methods. Then, the properties and preparation methods of physical and chemical cellulose hydrogels are described, respectively. The application of cellulose-based hydrogels as a tissue engineering scaffold (skin, bone and cartilage) in the biomedical field is introduced. Finally, the challenges and prospects of cellulose-based hydrogels in tissue engineering are summarized. Full article

(This article belongs to the Special Issue Synthesis and Application of Cellulose-Based Composites)

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