JOURNAL OF FOOD ENGINEERING
·
2020
·
IF 4.499
Ying Ji
The combination of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidization and annealing was applied to modify structural properties of corn starch in order to obtain starch polymer microgels. Microgels were characterized by X-ray diffraction, ATR-FTIR and thermogravimetry analysis (TGA). The effects of microgels on the uptake and release of lysozyme were also analyzed. The formation of oxidized microgels through the crosslinking between starch molecules and sodium trimetaphosphate was confirmed by X-ray diffraction. The ATR-FTIR analysis suggested that TEMPO-oxidation results in the formation of carboxyl groups. TGA data indicated that oxidized-annealed microgels had less thermal stability than oxidized microgels. Furthermore, the oxidized-annealed microgels had an improved capacity for uptake and release of lysozyme. At this stage of the exploration, microgels prepared from corn starches by annealing and oxidation is simple and efficient.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Bei Jiang,Meilin Li,Shuoang Cao,Zining Wang,Lijun Huang,Xinyi Song,Yuanqiao Zhang,Quanping Yuan
In order to increase the number and contact probability of electric dipole on cellulose, acid and alkali treatment was employed to extract hemicellulose and lignin from original wood to gain a highly oriented cellulose frame. The combined means with 2,2,6,6-tetramethylpiperidine-1-oxyl–NaBr–NaClO oxidation and impregnation of PDMS with compression was subsequently used to enhance its mechanical performance and electromechanical conversion. The assembled wooden electromechanical device (10 mm × 10 mm × 1 mm) exhibits the maximum open-circuit voltage (VOC) of 11.75 V and short-circuit current (ISC) of 211.01 nA as stepped by foot. It can be sliced to fabricate a flexible sensor with high sensitivity displaying VOC of 2.88 V and ISC of 210.09 nA under the tapped state. Its highly oriented wood fiber makes it display significant anisotropy in terms of mechanical and electromechanical performance for multidirectional sense. This strategy will exactly provide reference for developing other high-performance piezoelectric devices.
研究领域:
材料科学
·
生物工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Baolong Huo,Man Du,Ao Shen,Mengwen Li,Yaru Lai,Xue Bai,Aijun Gong,Leqiu Fang,Yunxu Yang
A highly selective and sensitive fluorescence “light-up” probe PTH for ClO − has been developed, which is designed by a new strategy based on TEMPO-oxidation for the first time. PTH exhibits excellent properties including quick response (within 2 min), lower detection limit (63.7 nM), good linearity ( R 2 = 0.9863) and specific selectivity. More importantly, its application of detection ClO- in real samples has also been achieved.
研究领域:
分析化学
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 3
·474
·
IF 4.967
Jing Liao,Huihua Huang
Nano chitin is a promising biocompatible material with wide applications. In this work, a fungal-derived nano chitin was prepared fromHericium erinaceusresidue via mineral/protein purification and subsequent TEMPO-mediated oxidation. The structure, dispersity, and gelation ability of the prepared fungal nano chitin were studied. The results showed that the average length and width of the prepared fungal nano chitin were 336.6 nm and 6.4 nm, respectively, and the aspect ratio exceeded 50:1. The nano chitin retained the basic structure of chitin, while the crystallization index was improved. In addition, the dispersity of the nano chitin in aqueous media was evaluated by the effective diameter, and the polydispersion index was mainly affected by pH and ionic strength. Under acetic acid “gas phase coagulation”, the prepared nano chitin dispersions with mass concentrations of 0.2, 0.4, 0.6, and 0.8% were converted into gels by enhanced hydrogen bond crosslinking between nano chitins.Keywords:nano chitin;TEMPO-mediated oxidation;dispersion stability;hydrogels
研究领域:
生物材料学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Guochen Xia,Shixu Yu,Zezhou Yang,Jingyi Lian,Yimin Xie,Qinghua Feng
Natural wood has been highly valued for thousands of years due to its excellent strength, low density, and ease of processing. However, its poor water stability, which leads to swelling and deformation, limits its competitiveness. In response, we designed a reconstructed wood through a process involving pretreatment, TEMPO oxidation, lignin self-assembly, lignin melting, and densification. In this material, cellulose serves as the skeleton, while lignin with a phenylpropyl structure acts as both a filler and binder. The resulting wood exhibits outstanding water stability, with no changes after 60 days of water immersion and a water absorption rate as low as 8.32 %. This stability is achieved through the densification of lignin, which is enhanced by lignin melting and pressure during self-assembly. The reconstructed wood not only offers excellent water stability but also boasts superior UV resistance and thermal stability. Additionally, it can be hot-pressed into straws within a mold, providing better water stability and tensile strength compared to paper straws. This reconstructed wood, made from natural wood and corncob, is biodegradable and environmentally friendly, offering a new approach to wood water stability strategies.
研究领域:
材料科学
·
林业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Gels
·
2024
·Vol. 10
·期 8
·490
·
IF 5
Minjie Hou,Qi Wang,Shunyu Wang,Zeze Yang,Xuefeng Deng,Hailong Zhao
Cellulose nanofibers (NF) were extracted from kapok fibers using TEMPO oxidation, followed by a combination of mechanical grinding and ultrasonic processing. The TEMPO-mediated oxidation significantly impacted the mechanical disintegration behavior of the kapok fibers, resulting in a high NF yield of 98%. This strategy not only improved the fibrillation efficiency but also reduced overall energy consumption during NF preparation. An ultralight and highly porous NF-based aerogel was successfully prepared using a simple ice-templating technique. It had a low density in the range of 3.5–11.2 mg cm−3, high compressional strength (160 kPa), and excellent thermal insulation performance (0.024 W m−1K−1). After silane modification, the aerogel displayed an ultralow density of 7.9 mg cm−3, good hydrophobicity with a water contact angle of 128°, and excellent mechanical compressibility with a high recovery of 92% at 50% strain. Benefiting from the silene support structure, it showed a high oil absorptive capacity (up to 71.4 g/g for vacuum pump oil) and a remarkable oil recovery efficiency of 93% after being reused for 10 cycles. These results demonstrate that our strategy endows nanocellulose-based aerogels with rapid shape recovery and high liquid absorption capabilities.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Processes
·
2024
·Vol. 12
·期 5
·1035
·
IF 2.8
Audrey Zahra,Virginia Ghita Firsty,Soo-Jeong Shin
Red ginseng extract is one of the most widely used herbal medicines to prevent and cure various diseases. Among the processed products derived from red ginseng, the water-insoluble part as red ginseng residual (RGR) becomes waste, even though it contains important ingredients. TEMPO-oxidation (TO) can be used as a pre-treatment with different degrees of oxidation (DO) (0 to 0.4) in red ginseng residual (RGR-TO) by introducing chemical oxidation and high-pressure homogenizer (HPH) as a nanofibrillation process.1H NMR was used to determine the carbohydrate composition and calculate DO, size was examined using a nanoparticle analyzer, and the zeta potential was used to determine surface charge density. RGR-TO with different concentrations had different compositions; glucose and uronic acid were the main ingredients. All treated RGR-TO showed higher oxidant levels than the untreated counterpart (RGR-TO 0). As the oxidant levels increased, the zeta potential and uronic acid increased, but the size of the nanofibril from RGR-TO decreased. The results of this study showed that TEMPO-oxidation pretreatment was effective in producing RGR cellulose nanofibril (CNF) with a variety of properties by adjusting the level of oxidation pretreatment and the number of HPH passes.
研究领域:
植物化学
·
药用植物学
·
纳米材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 7
·1130
·
IF 3.164
Dingyuan Zheng,Yangyang Zhang,Yunfeng Guo,Jinquan Yue
Herein, walnut shell (WS) was utilized as the raw material for the production of purified cellulose. The production technique involves multiple treatments, including alkaline treatment and bleaching. Furthermore, two nanocellulose materials were derived from WS by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidation and sulfuric acid hydrolysis, demonstrating the broad applicability and value of walnuts. The micromorphologies, crystalline structures, chemical functional groups, and thermal stabilities of the nanocellulose obtained via TEMPO oxidation and sulfuric acid hydrolysis (TNC and SNC, respectively) were comprehensively characterized. The TNC exhibited an irregular block structure, whereas the SNC was rectangular in shape, with a length of 55–82 nm and a width of 49–81 nm. These observations are expected to provide insight into the potential of utilizing WSs as the raw material for preparing nanocellulose, which could address the problems of the low-valued utilization of walnuts and pollution because of unused WSs.Keywords:Walnut shell;nanocellulose;TEMPO oxidation;sulfuric acid hydrolysis;ultrasonication
研究领域:
材料科学
·
农业废弃物利用
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Xuefeng Zhang,Huanbo Wang,Zhijun Chen,Shiyu Guo,Yuan Fu,Tian Liu
Fast-growing natural poplar wood is not meet with in many requirements such as high strength and flame retardant due to its porous structure and loose materials. In this study, we established a simple and feasible method that includes delignification, ionic bond formation via the crosslinking of carboxyl groups in TEMPO-oxidized wood after delignification with calcium ions , and hot-pressing of stacked veneers to improve the quality, density, strength, toughness, and weather resistance of natural wood (NW). This method has the following advantages: The inner cellulose microfiber is highly aligned, thus closely cross-linking and tightly bonding cellulose microfibers and nanofibers between the interfaces and inner layers of the wood boards via hydrogen bonding and ionic bonding. A laminated densified TEMPO-oxidized ionic wood (IW) showed substantially higher specific strength (∼196.9 MPa cm3 g−1), higher tensile strength (∼246 MPa), higher flexural strength (∼257 MPa), higher flexural modulus (∼36 GPa), higher impact toughness (∼42.34 kJ m−2), and superior fire retardancy, UV resistance, water resistance, and also higher density (∼1.25 g cm−3) than NW. Larger-size laminated densified structural materials with satisfactory thermal stability can also be fabricated using the proposed method.
研究领域:
材料科学
·
林业工程
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2021
·Vol. 29
·期 1
·213-222
·
IF 5.044
Fan Fangwei,Zhu Mengting,Fang Kaiyang,Cao Endi,Yang Yinzhi,Xie Jinpeng,Deng Zhongmin,Chen Yiren,Cao Xinwang
Cellulose nanowhiskers as one kind of renewable and biocompatible nanomaterials evoke much interest because of its versatility in various applications. Herein, the sisal cellulose nanowhiskers with ultrathin diameter of 5–10 nm, high crystallinity of 74% and C6 carboxylate groups converted from C6 primary hydroxyls were prepared via a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)/NaBr/NaClO system selective oxidization combined with mechanical homogenization. The effects of sodium hydroxide concentration in alkali pretreatment on the final sisal cellulose nanowhiskers were explored. It was found that with the increase of sodium hydroxide concentration, the sisal fiber crystalline type would change from cellulose I to cellulose II. The versatile sisal cellulose nanowhiskers would be particularly useful for applications in the nanocomposites as reinforcing phase, as well as in tissue engineering, filtration, pharmaceutical and optical industries as additives.
研究领域:
材料科学
·
生物材料学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Dingyuan Zheng,Zehuai Li,Wenrui Yao,Yuning Wang,Ce Sun,Haiyan Tan,Yanhua Zhang
Wood has garnered renewed interest due to its capacity to reduce carbon emissions when replacing non-renewable materials. Wood modification is often necessary because achieving optimal performance solely from the wood itself is challenging. Strategies for wood modification fall short of being genuinely sustainable and eco-friendly. In this context, a catalyst-free esterification method mediated by maleic anhydride (MA) is introduced for modifying wood. Notably, this approach aligns with principles of recycling, reuse, and reduction. A comprehensive comparison of MA-mediated wood esterification versus TEMPO-mediated wood oxidization highlights the effectiveness and superiorities of the MA esterification approach. Delignified wood esterified by MA (MA-DW) exhibits higher charge content (2.42 ± 0.24 vs. 0.53 ± 0.08 mmol/g), superior mass gain (18.4 ± 2.6 wt% vs. −15.92 ± 3.5 wt%), efficient recycling capability of the reaction medium (MA could be recycled five times, while TEMPO cannot be recycled), and integrity of the final products (retaining intact geometry vs. complete disintegration) compared to TEMPO-oxidized delignified wood (TEMPO-DW). Moreover, the MA-DW platform can serve in energy storage applications as an electrode or in sewage remediation applications as a catalyst. The esterification method mediated by MA provides an eco-friendly pathway for modifying wood, serving as a platform for creating diverse materials, potentially offering innovative concepts and insights for wood modification research.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Shengpeng Liu,Gen Cheng,Yun Xiong,Yigang Ding,Xiaogang Luo
Due to strong activity, it is very difficult to remove low concentrations of bromide in medical wastewater by traditional method, thus highly effective and greener adsorbents should be utilized to design. In this work, the cellulose beads (CBs) were modified by the TEMPO-mediated oxidation and then bonded with Fe 3+ to fabricate Fe(III)-complexed carboxylated cellulose beads (Fe-CCBs) adsorbents. Structure and properties of Fe-CCBs were analyzed using Energy dispersive spectrum (EDS), Scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR), total acidity and basicity groups, X-ray diffraction (XRD), N 2 adsorption-desorption and Thermogravimetric (TGA). Moreover, batch adsorption experiments showed that the adsorption of Br − was better consistent with general-order kinetic model and Liu isotherm model, which could also further clarify the adsorption process mechanism. Meanwhile, the results revealed that removal of Br- was a spontaneous exothermic process and was more suitable to be carried out under neutral or acidic conditions. Furthermore, the mechanism of adsorption behavior of bromide ions on Fe-CCBs was based on a combination of electrostatic attraction and outer-sphere complexation. The results of this study can provide guidance for the design of novel material adsorbents and the removal of harmful anions from aqueous solutions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）