CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Congcong Tong,Shuai Zhang,Tuhua Zhong,Zhengping Fang,Hongzhi Liu
Developing functional nanocellulose-based materials while well maintaining their inherent excellent attributes is crucial to achieve the value-added applications. However, their inherent flammability largely limits their potential applications in many fields with fire-safety concerns. In this work, an intrinsically flame-retardant nanofibrillated cellulose (NFC) was successfully prepared from kraft and unbleached bamboo pulps, respectively, via a three-step strategy involving quaternized pre-treatment, mechanical disintegration and subsequent borylation. TEM images show that the well-defibrillated cellulose nanofibrils with an average diameter of 5–9 nm were successfully obtained. The morphological, physicochemical, mechanical, thermal and flame-retardant characteristics of NFC suspensions, and their resulting films were systematically characterized. The borylated NFC film from the kraft pulp (B/Q-NFC) exhibits remarkably improved char yield while retaining high degree of fibrillation, optical transparency and mechanical properties of the Q-NFC one. Despite relatively lower optical transmittance and tensile strength, the lignin-containing NFC (L-Q-NFC) from unbleached pulp exhibits better thermal stability and outstanding UV-shielding function. Flame-retardant properties of borylated NFC samples were comprehensively investigated in terms of microscale combustion calorimetry (MCC), limiting oxygen index (LOI), vertical burning, and cone calorimetry tests. A synergistic effect was noted between B and lignin species in promoting flame resistance of Q-NFC matrix (L-B/Q-NFC). When being used as flame-retardant coatings on the filter paper and PET film, both of borylated NFC films display excellent flame-retardancy and smoke-suppression effects. In combination with of surface and bulk chemical composition analysis, TGA results as well as oxygen-permeability and thermal diffusivity measurements, the flame-retardant mechanism of borylated NFC films was elucidated. These favorite features enable them to act as sustainable fire-protective coatings for many fields such as thermal insulation, electronics, separators for lithium-ion battery, etc.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2025
·
IF 4.8
Liu Yutong,Wang Hankun,Zhong Tuhua
In this study, micro-nanofibrillated cellulose (MNFC) was prepared using an environmentally friendly approach. Specifically, bamboo pulp was pretreated through high-consistency mechano-enzymatic fibrillation, followed by high-speed blending and dispersion, resulting in MNFC with a diameter of 9.77 ± 3.83 nm and a water retention capacity of up to 1207%. The prepared MNFC was utilized as a reinforcing material for poly(acrylic acid-acryloylamino-2-methyl-1-propanesulfonic acid) P(AA-AMPS) hydrogels, aiming to enhance their mechanical properties and water absorption capacity. The effects of incorporating high-content MNFC on the mechanical and water absorption properties of the hydrogels were investigated. The results demonstrated that, compared to hydrogels without MNFC, the addition of MNFC led to a more uniform material structure, with the hydrogel fully recovering its original shape after 80% compressive deformation. The incorporation of 5% MNFC increased the compressive stress strength of the P(AA-AMPS) hydrogel by tenfold, while the addition of 15% MNFC improved the water absorption rate by 68% and the initial water retention capacity by 3.4 times. More importantly, compared to traditional low consistency nanocellulose production methods, the MNFC preparation method in this study is more environmentally friendly and efficient, offering a cost-effective alternative. The introduction of high-content MNFC not only increases the proportion of biomass materials in the hydrogel, reducing reliance on petroleum-based materials, but also constructs a robust network structure, significantly enhancing the mechanical strength and water absorption performance of the hydrogel. These P(AA-AMPS) hydrogels, reinforced with high-content MNFC and exhibiting excellent mechanical properties and ultra-high water absorption capacity, show great potential for applications in agriculture, hygiene, and the food industry. Graphical abstract
研究领域:
材料科学
·
环境科学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2019
·
IF 0
Arun Saini,Chandravati Yadav,Bai-Liang Xue,Nan Wang,Lei Dai,Xinping Li
In this study, a mixed-acid-assisted system utilizing a combination of a weak acid (citric acid, CA) and strong acid (H2SO4, SA) under hydrothermal reaction conditions was proposed for simultaneous preparation and modification (carboxylation) of cellulose nanocrystals (CNCs). Bleached bamboo pulp was used as the cellulose source, and the optimized reaction conditions were further used to produce carboxylated CNCs (cCNCs) from microcrystalline cellulose and Whatman 1 filter paper. Different concentrations of CA and SA (namely, 40 wt % CA (optimized concentration) and 5, 10, 20, and 30 wt % SA) were used for the hydrolytic processing of raw cellulosic material under hydrothermal conditions. The effect of various concentrations of CA and SA on the yield, carboxylate content, microstructure, crystallinity, thermal, and rheological characteristics of cCNCs were methodically investigated and contrasted. The optimized hydrothermal reaction conditions performed for 4 h at 100 °C using a mixture of 40 wt % CA and only 20 wt % SA yielded needle-shaped cCNCs with a yield higher than 70%. The carboxyl functionalization of CNCs was affirmed through Fourier transform infrared spectroscopy and conductometric titrimetric method. The results revealed the carboxylate content of 1.18 mmol/g corresponding to an average degree of oxidation of ∼0.20. The length of nanocrystals lies in the range of 280–420 nm with diameter ranging from 10 to 20 nm, as was perceived through microstructural analytical tools like field emission scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Dynamic light scattering analysis gives an average size of ∼200 nm. The visual inspection revealed high colloidal stability of cCNCs dispersions, which was further supported through its appreciable Zeta potential value of ca. −49.5 mV. Further, the rheological characterizations revealed typical features reminiscent of critical gels showing elastic behavior of cCNCs. Nanocomposite films of hydroxypropyl methylcellulose (HPMC) with different loadings of cCNCs were fabricated using a simple solvent casting method. The incorporation of very small amounts of cCNCs (0.1 wt %) in HPMC resulted in ∼58% increment in tensile strength, ∼10% increment in modulus, and ∼82% increment in elongation. Moreover, the composite films exhibited high transparency and appreciable water barrier properties that allow their potential application as barrier and transparent films for various applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Chunxia Pang,Huanhuan You,Sijie Lei,Fan Su,Lili Liang,Zhanguo Li,Xiaoyan Lin,Yaping Zhang,Hao Zhang,Xunhai Pan,Yang Hu
The surface chemical composition of materials is essential for regulating their charge trapping and storage capabilities, which directly affect their electret performance. Although chemical modification of materials to alter electret performance has been investigated, the mechanism through which electret properties are regulated more systematically via chemical customization has not been elucidated in detail. Herein, p -phenylenediamine, benzidine and 4,4′-diaminotriphenyl, which have different conjugated strength functional groups, were selected to chemically tailor the surface of bamboo pulp fibers to regulate the electret properties and elucidate the regulatory mechanism more systematically. The results showed that the charge trapping and storage properties of materials could be regulated by introducing functional groups with different conjugated strengths to their surfaces, realizing the regulation of the electret properties. Moreover, the charge trapping and storage ability could be tailored more specifically by regulating the number of functional groups. By chemical customization to provide electrostatic effects to the materials, the purification time was reduced by approximately 45 %–52 %. More importantly, a relatively systematic mechanism was proposed to elucidate the effect of the conjugate group strength on the charge trapping and charge storage properties of the material. These findings will provide guidance for the investigation of chemical modifications to regulate the electret performance of materials.
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
NORDIC PULP & PAPER RESEARCH JOURNAL
·
2019
·Vol. 35
·期 1
·18-24
·
IF 0.929
Hailong Li,Chao Du,Shujuan Ge,Mengru Liu
This study aimed to investigate the oxalate formation mechanism during chlorine dioxide (
ClO
2
) bleaching of bamboo kraft pulp, and thus explore favourable
ClO
2
bleaching conditions to better control oxalate formation. The amount of oxalate formed varied linearly with
ClO
2
dosage within the whole research range, while it rose exponentially within the first 90 mins of pulp bleaching. Then the actual bleaching process was simulated by reacting
ClO
2
with three representative lignin model compounds and comparatively studied. The rule of oxalate formation in the simulated reaction system was identical to that in pulp bleaching by
ClO
2
, except for oxalate production by veratraldehyde with prolonged reaction time. Under identical conditions, vanillin formed the highest amount of oxalate, while veratraldehyde formed the least. Furthermore, the amount of oxalate formed increased by 19.59 mg/kg when the kappa number of the delignified pulp was reduced by one unit. Considering the satisfactory pulp brightness and decreased oxalate formation, the recommended conditions for
ClO
2
bleaching of bamboo kraft pulp were a
ClO
2
dosage of 4 %, 60 °C and 70 mins.
研究领域:
制浆造纸工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2020
·
IF 4.244
Qiuyan Chen,Xinping Wang,Hai Huang,Shilin Cao,Lihui Chen,Liulian Huang,Xiaojuan Ma
The development of effective separation of hemicelluloses from fully bleached cellulosic pulp fibers is conducive to the development and utilization of high value-added cellulose products. In this study, Turkey Red Oil (sulfonated castor oil) (TRO), a renewable source, was proposed to facilitate hemicelluloses separation from chemical pulp in cold caustic extraction (CCE). As expected, TRO application can significantly promote hemicelluloses separation in the CCE process. By contrast to the traditional CCE process, TRO/CCE could decrease the hemicelluloses content from 9.1 to 6.1%, while the hemicelluloses removal selectivity increased from 72.5 to 82.3% and efficiency, increased from 52.4 to 68.1%. Moreover, without sacrificing hemicelluloses removal, the TRO utilization can reduce the alkaline consumption and therefore preserve the cellulose I crystal from conversion to cellulose II. Additionally, the TRO/CCE procedure made the cellulose fiber more flexible and more accessible to react with CS 2 and therefore a high Fock reactivity.
研究领域:
制浆造纸工程
·
可再生资源利用
·
生物质化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2014
·
IF 5.323
Hongyi Liu,Xiaogang Yang,Yong Zhang,Hangcheng Zhu,Juming Yao
This work presents a synthesis process and flocculation characteristics of an eco-friendly flocculant based on bamboo pulp cellulose (BPC) from Phyllostachys heterocycla . Ployacrylamide (PAM) was grafted onto the BPC by free-radical graft copolymerization in homogeneous aqueous solution. The optimal synthesis conditions of the bamboo pulp cellulose-graft-ployacrylamide flocculant (BPC-g-PAM) and its performance on wastewater treatments were investigated. A UV-based method was used to rapidly determine the degree of substitution (DS) of BPC. The results showed that, under the optimal synthesis conditions, the obtained BPC-g-PAM held a grafting ratio of 43.8% and DS of 1.31. Turbidity removal of the product reached 98.0% accompanying with the significant flocculation and sedimentation in target suspensions. The flocculation mechanism was explored by means of zeta potential method. For negatively charged contaminants, like kaolin clay particles, the BPC-g-PAM could remove the contaminants efficiently via bridging and charge neutralization in acidic or neutral environment.
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
CELLULOSE
·
2017
·Vol. 24
·期 12
·5639-5647
·
IF 3.417
Yang Xiaogang,Zhang Lianwei,Jin Xu,Liu Lin,Zhang Yong,Ni Qingqing,Yao Juming
In this work, an efficient and hydrophobic bamboo pulp cellulose-graft-sodium silicate–polyacrylamide (BPC-g-Si–PAM) flocculant was designed and synthesized to improve its flocculation performance as well as the dewatering efficiency of coagulation sludge. The optimal synthesis process of BPC-g-Si–PAM and its optimal flocculation conditions on wastewater treatment were investigated in detail. Compared with unmodified BPC-g-PAM and commercial PAM, hydrophobic BPC-g-Si–PAM flocculant exhibited better flocculation performance with SV30 of 5.8%. Moreover, TSS, COD and turbidity reduction for machining wastewater reached upto 98.1, 86.8 and 97.6%, respectively. Compared with commercial PAM, removal rate increased by 2.69, 7.68 and 2.68%, respectively. And also BPC-g-Si–PAM exhibited higher removal efficiency for ammonia nitrogen (77.7%), total iron (99.3%), total phosphorus (93.6%) and total zinc (96.7%) than PAM. All the results demonstrated that hydrophobic BPC-g-Si–PAM has a potential application prospect in industrial wastewater treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2017
·Vol. 11
·期 4
·554-563
·
IF 1.712
Wu Bozhen,Geng Biyao,Chen Yufei,Liu Hongzhi,Li Guangyao,Wu Qiang
Bleached bamboo kraft pulp was pretreated by 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO)- mediated oxidation using a TEMPO/NaBr/NaClO system at pH = 10 in water to facilitate mechanical disintegration into TEMPO-oxidized cellulose nanofibrils (TO-CNs). A series of TO-CNs with different carboxylate contents were obtained by varying amounts of added NaClO. An increase in carboxylate contents results in aqueous TO-CN dispersions with higher yield, zeta potential values, and optical transparency. When carboxylate groups are introduced, the DPv value of the TO-CNs remarkably decreases and then levels off. And the presence of hemicellulose in the pulp is favorable to TEMPO oxidization. After the oxidization, the native cellulose I crystalline structure and crystal size of bamboo pulp are almost maintained. TEM micrographs revealed that the degree of nanofibrillation is directly proportional to the carboxylate contents. With increasing carboxylate contents, the free-standing TO-CN films becomes more transparent and mechanically stronger. The oxygen permeability of PLA films drastically decreases from 355 for neat PLA to 8.4 mL∙m –2 ∙d –1 after coating a thin layer of TO-CN with a carboxylate content of 1.8 mmol∙g –1 . Therefore, inexpensive and abundant bamboo pulp would be a promising starting material to isolate cellulose nanfibrils for oxygen-barrier applications.
研究领域:
高分子材料
·
纳米纤维素
·
包装材料
·
生物基材料
·
阻隔性能
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2018
·Vol. 26
·期 3
·1683-1701
·
IF 3.809
Ru Jing,Tong Congcong,Chen Ning,Shan Pengjia,Zhao Xingke,Liu Xuying,Chen Jinzhou,Li Qian,Liu Xiaohuan,Liu Hongzhi,Zhao Ying
Abstract In this work, quaternized nanofibrillated cellulose (Q-NFC) was isolated from bamboo bleached kraft pulp through the pre-treatment using 2, 3-epoxy-propyltrimethylammonium chloride (EPTAC) in an aqueous alkaline media and subsequent high-pressure homogenization. A series of aqueous Q-NFC dispersions with different contents of positively charged trimethylammonium groups on the surfaces of fibrils were obtained. With the amount of added EPTAC increased, the solid recovery ratio, surface charge contents, zeta potential values, and extent of nanofibrillation gradually increased for the as-obtained Q-NFCs. TEM images of Q-NFCs revealed that the incorporation of quaternary ammonium groups contributed to the defibrillation into finer nanofibrils with more uniform width distribution. With an increase in the positive charge contents, both degree of polymerization and decomposition temperature of the Q-NFC films decreased slowly. Steady-state rheological result demonstrated that the maximum shear viscosity was achieved for the Q-NFC0.6 dispersion with the medium charge content. The Q-NFC films with higher charge content displayed superior transparency and tensile strength. Furthermore, the oxygen transmission rate of PLA films was remarkably decreased dramatically from 216.0 to 10.3 mL m −2 day −1 after laminating a thin layer of Q-NFC0.6 on the one side. As compared to TEMPO-oxidized NFC from the same pulp, the surface-charged Q-NFC exhibited higher optical transmittance, shear viscosity, and thermal stability as well as comparable oxygen-barrier properties. Graphical abstract
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Hangcheng Zhu,Yong Zhang,Xiaogang Yang,Lan Shao,Xiumei Zhang,Juming Yao
The discharge of effluents from surfactant manufacturers is giving rise to increasingly serious environmental problems. In order to develop the eco-friendly flocculation materials to achieve effective removal of pollutants from the surfactant effluents, the bamboo pulp cellulose from Phyllostachys heterocycla is employed as the skeleton material to synthesize an eco-friendly bamboo pulp cellulose-g-polyacrylamide (BPC-g-PAM) for flocculation. The BPC-g-PAM is used with the metal ions as the coagulant to treat the effluent from a surfactant manufacturer. The response surface methodology coupled with Box–behnken design is employed to optimize the key factors of coagulation–flocculation. The results show that the combination of Fe 3+ with BPC-g-PAM achieves the best coagulation–flocculation performance like, the fast treatment time, minimum coagulant and BPC-g-PAM dosages compared with the other two combinations of Al 3+ with BPC-g-PAM and Ca 2+ with BPC-g-PAM. Therefore, the combination of Fe 3+ with BPC-g-PAM is expected to promote its application for the pollution control in the surfactant manufacturers.
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Chunxia Pang,Huanhuan You,Lili Liang,Zhanguo Li,Xiaoyan Lin,Yaping Zhang,Hao Zhang,Xunhai Pan,Yang Hu,Yan Chen,Xuegang Luo,Haijun Wang
Radioactive aerosols in confined spaces of workplaces are the main source of internal radiation hazards for staff. Therefore, biomass-based electret fiber materials as alternatives of petroleum-based polymers will be of great potential in capturing radioactive aerosols due to its biodegradability , renewability and electrostatic effects. Herein, a fabrication strategy of bamboo pulp-based electret fiber aerogels by corona polarization is reported grounded on p-phenylenediamine (PPD)-modified bamboo pulp fibers (BCFs) and ethyl cellulose (EC). The morphology, chemical structure , and physical properties of BCFs before and after modification, as well as the electret properties and purification performance of fiber aerogel were analyzed. The results showed that PPD can be grafted uniformly on the surface of BCFs, making the fibers transform from irregular cylindrical shape with hierarchical surface to regular cylindrical shape with smooth surface, and can improve the surface potential of the fibers, one of the considerably great electret properties, from 0.00 kV to 1.33 kV when the graft amount of PPD was 0.500 g/g. The improvement in surface potential, leading by the grafted PPD structure which is a charge-trapping site confirmed by stoichiometric calculations, enhance the electrostatic trapping effect of the fibers on radioactive aerosol particles and shorten the purification time from 26 min to 15 min. Moreover, the electret fiber aerogel with modified BCFs (named as PPD-DABCFs) has a low air resistance of 56 Pa at the flow speed of 5.3 cm·s −1 , a light base weight of 62.7 g·m −2 and a long service life. Therefore, the bamboo pulp-based electret fiber aerogel has a promising application in the field of radioactive aerogel purification.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）