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Dialdehyde cellulose nanocrystal cross-linked chitosan foam with high adsorption capacity for removal

《化学科学与工程前沿(英文)》 2023年 第17卷 第7期   页码 853-866 doi: 10.1007/s11705-022-2256-x

摘要: The discharge of large amounts of dye-containing wastewater seriously threats the environment. Adsorbents have been adopted to remove these dyes present in the wastewater. However, the high adsorption capacity, predominant pH-responsibility, and excellent recyclability are three challenges to the development of efficient adsorbents. The poly(acryloxyethyl trimethylammonium chloride)-graft-dialdehyde cellulose nanocrystals were synthesized in our work. Subsequently, the cationic dialdehyde cellulose nanocrystal cross-linked chitosan nanocomposite foam was fabricated via freeze-drying of the hydrogel. Under the optimal ratio of the cationic dialdehyde cellulose nanocrystal/chitosan (w/w) of 12/100, the resultant foam (Foam-12) possesses excellent absorption properties, such as high porosity, high content of active sites, strong acid resistance, and high amorphous region. Then, Foam-12 was applied as an eco-friendly adsorbent to remove acid red 134 (a representative of anionic dyes) from aqueous solutions. The maximum dye adsorption capacity of 1238.1 mg∙g‒1 is achieved under the conditions of 20 mg∙L‒1 adsorbents, 100 mg∙L‒1 dye, pH 3.5, 24 h, and 25 °C. The dominant adsorption mechanism for the anionic dye adsorption is electrostatic attraction, and Foam-12 can effectively adsorb acid red 134 at pH 2.5–5.5 and be desorbed at pH 8. Its easy recovery and good reusability are verified by the repeated acid adsorption–alkaline desorption experiments.

关键词: chitosan foam     cellulose nanocrystals     acid red 134     adsorption    

Removal of copper by modified chitosan adsorptive membrane

Xiaoshuai LIU, Zihong CHENG, Wei MA

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 102-106 doi: 10.1007/s11705-009-0123-7

摘要: In this study, a novel adsorptive membrane was prepared from chitosan as the functional polymer and some additive blend solutions by solution casting method. The modified chitosan membrane was characterized by FTIR and its Water Swelling Ratio (WSR). The adsorption of copper ions on the adsorptive membrane was investigated in batch experiments. The results obtained from the experiments indicated that the membrane had a good adsorption capacity for copper ions, the optimal ionic strength and pH were 0.1 and 5-6, respectively. Compared with the Langmuir isotherm model, the experimental data were found to be following the Freundlich model.

关键词: chitosan     adsorptive membrane     copper removal     environmental engineering     heavy metal     isotherm model    

Correction to: Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlled

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1704-2

Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Yao NIE,Shubo DENG,Bin WANG,Jun HUANG,Gang YU

《环境科学与工程前沿(英文)》 2014年 第8卷 第5期   页码 675-682 doi: 10.1007/s11783-013-0622-0

摘要: Polyethylenimine (PEI)-modified chitosan was prepared and used to remove clofibric acid (CA) from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy (SEM) showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg·g for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg·g on the porous chitosan. The CA adsorption on the PEI-modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceuticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI-modified chitosan has a potential application for the removal of some anionic micropollutants from water or wastewater.

关键词: clofibric acid     PEI-modified chitosan     adsorption capacity     adsorption mechanism     electrostatic interaction    

Facile strategy for carbon foam fabrication with lignin as sole feedstock and its applications

《化学科学与工程前沿(英文)》 2023年 第17卷 第8期   页码 1051-1064 doi: 10.1007/s11705-022-2248-x

摘要: This research is a follow-up to our recent discovery of a facile strategy for directly converting lignin powder into carbon foam. In this work, we report that the thermal pretreatment parameters in air can remarkably influence the formation and properties of the derived carbon foam. Thermal pretreatment parameters (heating rate, temperature, and residence time) were systematically investigated and a conversion mechanism into carbon foam was proposed. During the thermal pretreatment, relatively low temperatures, low heating rates, and short residence time hindered the formation of smooth and well-connected structures in the carbon foam. The overall product yields were similar regardless of the thermal pretreatment conditions. The densities of the different carbon foams ranged 0.27–0.83 g∙cm−3. The carbon foams with the highest compressive strengths (> 10 MPa) were KLPC280-2-5, KLPC300-0-5, and KLPC300-2-2.5. KLPC280-2-5 exhibited a high iodine sorption value (182 mg∙g−1). KLPC300-2-5 exhibited a specific capacitance of 158 F∙g−1 at a current density of 0.05 A∙g−1. The maximum evaporation rates in the solar vapor generation experiments were 1.05 and 1.38 kg∙m−2∙h−1 under 100 and 150 mW∙cm−2 irradiation, respectively. The good performances are attributed to the robust, porous, and continuous structure.

关键词: lignin     carbon foam     thermal pretreatment     solar vapor generation    

Effect of IL-10 on formation of foam cell induced by ox-LDL

WANG Fei, DAI Yalei, XU Ting, XU Bo, WANG Kaifeng

《医学前沿(英文)》 2008年 第2卷 第3期   页码 298-302 doi: 10.1007/s11684-008-0057-3

摘要: Atherosclerosis is a chronic disease that causes various cardiovascular complications. It has been realized that cellular and humoral immunity plays crucial roles in atherogenic lesion formation. In this study the effects of lipopolysaccharide (LPS) and interleukin-10 (IL-10) on the formation of foam cells during the early stages of atherosclerosis have been investigated. Macrophage was induced by phorbol myristate acetate (PMA) treatment on THP-1 cells. The cells were further stimulated by ox-LDL, ox-LDL plus LPS, ox-LDL plus IL-10 and LPS. By using an oil red O staining technique, the formation of foam cells was evaluated by lipid granules formation in the cells. The ratio of foam cell formation was increased from (9.77 ± 1.70)% to (16.27 ± 2.27)% after 24 h stimulation with ox-LDL, and the increase was observed with incubating time. The foam cells were significantly increased in the presence of LPS in a dose-dependent manner. The maximum increase of about 40% was observed. However, the significant elevation by LPS was abrogated when IL-10 was added. These results indicated that IL-10 can effectively prevent the formation of foam cells induced by ox-LDL with or without LPS. This study demonstrates that ox-LDL can cause foam cell formation from macrophages . LPS can significantly accelerate this event. IL-10, an anti-inflammatory cytokine, can inhibit the effect of ox-LDL and LPS. These results indicate that inflammatory effects in blood vessels can speed up foam cell formation. The inhibitive effect of IL-10 is an important factor for delaying atherosclerosis processes.

关键词: inflammatory     presence     interleukin-10     dose-dependent     ox-LDL    

Stability of three-dimensional printable foam concrete as function of surfactant characteristics

《结构与土木工程前沿(英文)》   页码 935-947 doi: 10.1007/s11709-023-0964-z

摘要: Extrudability is one of the most critical factors when designing three-dimensional printable foam concrete. The extrusion process likely affects the foam stability which necessitates the investigation into surfactant properties particularly for concrete mixes with high foam contents. Although many studies have been conducted on traditional foam concrete in this context, studies on three-dimensional printed foam concrete are scarce. To address this research gap, the effects of surfactant characteristics on the stability, extrudability, and buildability of three-dimensional printed foam concrete mixes with two design densities (1000 and 1300 kg/m3) using two different surfactants and stabilizers (synthetic-based sodium lauryl sulfate stabilized with carboxymethyl cellulose sodium salt, and natural-based hingot surfactant stabilized with xanthan gum) were investigated in this study. Fresh density tests were conducted before and after the extrusion to determine stability of the foam concrete. The results were then correlated with surfactant qualities, such as viscosity and surface tension, to understand the importance of key parameters in three-dimensional printing of foam concrete. Based on the experimental results, surfactant solu1tion with viscosity exceeding 5 mPa·s and surface tension lower than 31 mN/m was recommended to yield stable three-dimensional printable foam concrete mixes. Nevertheless, the volume of foam in the mix significantly affected the printability characteristics. Unlike traditional foam concrete, the variation in the stabilizer concentration and density of concrete were found to have insignificant effect on the fresh-state-characteristics (slump, slump flow, and static yield stress) and air void microstructure of the stable mixes.

关键词: foam concrete     3D printable concrete     stability     rheology     air void microstructure    

The role of single deformed bubble on porous foam tray with submerged orifices on the mass transfer enhancement

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 2127-2143 doi: 10.1007/s11705-023-2363-3

摘要: Foam trays with porous submerged orifices endow bubbles uniformly distributed, which are considered attractive column internals to enhance the gas-liquid mass transfer process. However, its irregular orifice and complex gas-liquid flow make it lack pore-scale investigations concerning the transfer mechanism of dynamic bubbling. In this work, the actual porous structure of the foam tray is obtained based on micro computed tomography technology. The shape, dynamic, and mass transfer of rising bubbles at porous orifices are investigated using the volume of fluid and continue surface force model. The results demonstrate that the liquid encroaching on the gas channels causes the increasing orifices velocity, which makes the trailing bubble easily detach from the midst of the leading bubble and causes pairing coalescence. Additionally, we found that the central breakup regimes significantly improve the gas-liquid interface area and mass transfer efficiency. This discovery exemplifies the mechanism of mass transfer intensification for foam trays and serves to promote its further development.

关键词: bubble formation     porous submerged orifices     process intensification     foam tray    

An antifouling catechol/chitosan-modified polyvinylidene fluoride membrane for sustainable oil-in-water

Shanshan Zhao, Zhu Tao, Liwei Chen, Muqiao Han, Bin Zhao, Xuelin Tian, Liang Wang, Fangang Meng

《环境科学与工程前沿(英文)》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1355-5

摘要: Abstract • Underwater superoleophobic membrane was fabricated by deposition of catechol/chitosan. • The membrane had ultrahigh pure water flux and was stable under harsh pH conditions. • The membrane exhibited remarkable antifouling property in O/W emulsion separation. • The hydration layer on the membrane surface prevented oil droplets adhesion. Low-pressure membrane filtrations are considered as effective technologies for sustainable oil/water separation. However, conventional membranes usually suffer from severe pore clogging and surface fouling, and thus, novel membranes with superior wettability and antifouling features are urgently required. Herein, we report a facile green approach for the development of an underwater superoleophobic microfiltration membrane via one-step oxidant-induced ultrafast co-deposition of naturally available catechol/chitosan on a porous polyvinylidene fluoride (PVDF) substrate. Membrane morphology and surface chemistry were studied using a series of characterization techniques. The as-prepared membrane retained the original pore structure due to the ultrathin and uniform catechol/chitosan coating. It exhibited ultrahigh pure water permeability and robust chemical stability under harsh pH conditions. Moreover, the catechol/chitosan hydrophilic coating on the membrane surface acting as an energetic barrier for oil droplets could minimize oil adhesion on the surface, which endowed the membrane with remarkable antifouling property and reusability in a cyclic oil-in-water (O/W) emulsion separation. The modified membrane exhibited a competitive flux of ~428 L/(m2·h·bar) after three filtration cycles, which was 70% higher than that of the pristine PVDF membrane. These results suggest that the novel underwater superoleophobic membrane can potentially be used for sustainable O/W emulsions separation, and the proposed green facile modification approach can also be applied to other water-remediation materials considering its low cost and simplicity.

关键词: Antifouling     Catechol/chitosan co-deposition     Oil-in-water emulsions separation     Underwater superoleophobic    

Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1416-4

摘要:

• Solvent-free chitosan oxidation is obtained by rapid mechanochemical reaction.

关键词: Chitosan     High energy ball milling     Mechanochemistry     Oxidation    

Anthocyanins/chitosan films doped by nano zinc oxide for active and intelligent packaging: comparison

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 704-715 doi: 10.1007/s11705-022-2270-z

摘要: The multifunctional films was prepared by blending chitosan and nano-ZnO with purple tomato anthocyanins or black wolfberry anthocyanins. The properties of films functioned by anthocyanins source and nano-ZnO content were studied. It was found purple tomato anthocyanins showed more significant color change against pH than black wolfberry anthocyanins. The nano-ZnO were widely dispersed in matrix and enhanced the compatibility of anthocyanins with chitosan. However, the anthocyanins source influenced the properties of the films more slightly than nano-ZnO addition. The tensile strength, antioxidant and antibacterial effects of the chitosan films dramatically increased after cooperated by nano-ZnO and anthocyanins, which also enhanced with increase of nano-ZnO content, whereas the elongation at break of the composite films decreased. Especially, the anthocyanin and nano-ZnO promoted the antibacterial activity of films synergistically. Composite films made from black wolfberry anthocyanins exhibited higher mechanical performance than those made from purple tomato anthocyanins but weaker antibacterial effects. The purple tomato anthocyanins/chitosan and nano-ZnO/purple tomato anthocyanins/chitosan films effectively reflected pork spoilage, changing their colors from dark green to brown, indicating the potential for applications in active and intelligent food packaging.

关键词: bio-based     multifunction     colorimetric indicator     active and intelligent packaging    

Nano-hydroxyapatite formation via co-precipitation with chitosan-g-poly(

Yang YU, Hong ZHANG, Hong SUN, Dandan XING, Fanglian YAO

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 388-400 doi: 10.1007/s11705-013-1355-0

摘要: With the excellent biocompatibility and osteoconductivity, nano-hydroxyapatite (nHA) has shown significant prospect in the biomedical applications. Controlling the size, crystallinity and surface properties of nHA crystals is a critical challenge in the design of HA based biomaterials. With the graft copolymer of chitosan and poly( -isopropylacrylamide) in coil and globule states as a template respectively, a novel composite from chitosan-g-poly( -isopropylacrylamide) and nano-hydroxyapatite (CS-g-PNIPAM/nHA) was prepared via co-precipitation. Zeta potential analysis, thermogravimetric analysis and X-ray diffraction were used to identify the formation mechanism of the CS-g-PNIPAM/nHA composite and its morphology was observed by transmission electron microscopy. The results suggested that the physical aggregation states of the template polymer could induce or control the size, crystallinity and morphology of HA crystals in the CS-g-PNIPAM/nHA composite. The CS-g-PNIPAM/nHA composite was then introduced to chitosan-gelatin (CS-Gel) polyelectronic complex and the cytocompatibility of the resulting CS-Gel/composite hybrid film was evaluated. This hybrid film was proved to be favorable for the proliferation of MC 3T3-E1 cells. Therefore, the CS-g-PNIPAM/nHA composite is a potential biomaterial in bone tissue engineering.

关键词: chitosan     poly(N-isopropylacrylamide)     hydroxyapatite     coil     globule     bone tissue engineering    

NiFeRuOx nanosheets on Ni foam as an electrocatalyst for efficient

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1698-1706 doi: 10.1007/s11705-023-2334-8

摘要: The electrocatalyst NiFeRuOx/NF, comprised of NiFeRuOx nanosheets grown on Ni foam, was synthesized using a hydrothermal process followed by thermal annealing. NiFeRuOx/NF displays high electrocatalytic activity and stability for overall alkaline seawater splitting: 98 mV@ 10 mA∙cm−2 in hydrogen evolution reaction, 318 mV@ 50 mA∙cm−2 in oxygen evolution reaction, and a cell voltage of 1.53 V@ 10 mA∙cm−2, as well as 20 h of durability. A solar-driven system containing such a bifunctional NiFeRuOx/NF has an almost 100% Faradaic efficiency. The NiFeRuOx coating around Ni foam is an anti-corrosion layer and also a critical factor for enhancement of bifunctional performances.

关键词: NiFeRuOx nanosheets     Ni foam     electrocatalysis     overall seawater splitting     solar-driven system    

Chitosan/polyethylene glycol impregnated activated carbons: Synthesis, characterization and adsorption

Ehsan Salehi, Fereshteh Soroush, Maryam Momeni, Aboulfazl Barati, Ali Khakpour

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 575-585 doi: 10.1007/s11705-017-1650-2

摘要: Novel modified activated carbons (ACs) with enhanced adsorptive properties were obtained coating by chitosan (CS), polyethylene glycol (PEG) and blends of the two polymers (0:1, 1:0, 1:1, 1:2 and 2:1 wt/wt) on ACs by an impregnation technique. The adsorption performances of the pristine, acidified and polymer-impregnated ACs were studied using methylene blue as a model adsorbate. The adsorbents were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and abrasion hardness tests. The average coating thicknesses were between 10 to 23 microns. The pore sizes, pore densities and pore capacities of the activated carbons increased as the wt-% PEG in the coating increased. The highest adsorption capacity (424.7 mg/g) was obtained for the chitosan-coated ACs and this adsorption was well described by the Langmuir isotherm model. The kinetic results were best described by the pseudo-second-order kinetic model. The highest rate constant was obtained with the ACs modified with the CS:PEG (2:1) coating and this result was almost 2.6 times greater than that of the unmodified ACs. The CS/PEG impregnated ACs also displayed superior hardness (~90%), compared to unmodified ACs (~85%). Overall the chitosan had a greater effect on improving adsorption capacity whereas the polyethylene glycol enhanced the adsorption rate.

关键词: carbon biocomposites     impregnation     chitosan     polyethylene glycol     image processing    

Reliability of foam posturography in assessment of postural balance in the patients with vertigo

LIU Bo, KONG Weijia

《医学前沿(英文)》 2008年 第2卷 第4期   页码 361-365 doi: 10.1007/s11684-008-0069-z

摘要: The postural balance is a important aspect of assessment in vestibular rehabilitation therapy. As the computerized dynamic posturography, the foam posturography performed by using foam in posturography is a useful measurement tool for postural balance. Then, the reliability of foam posturography is critical in clinic. To our knowledge, there is no report about the test-retest reliability of foam posturography in the patients with vertigo in China. The foam posturography was taken on the patients with vertigo in stable state and repeated in 3 to 5 days. In the two assessments of test and retest, all subjects stood under 4 sensory conditions, such as firm surface with eyes open (T1), firm surface with eyes closed (T2), foam surface with eyes open (T3) and foam surface with eyes closed (T4) for 30 seconds respectively. The average sway velocity (SV) of center of pressure (COP) under feet of upright standing was recorded as research parameter. The results of patients with vertigo were compared with those of normal subjects. It demonstrated that all normal subjects did not fall in the two assessments. There were 10 of 34 patients with vertigo at least fell one time during the two assessments, and the SVs of these subjects did not taken the analysis of test-retest reliability. The results showed that: (1) The interclass correlation coefficients (ICC) of all 49 subjects including normal subjects and patients without falling were 0.887–0.973 according to the T1–T4 between two assessment. (2) The SVs between the normal subjects and patients were significantly different in the T2 ( = 2.018, = 0.049) and T4 ( = 3.905, < 0.001) in the first assessment and in the T4 ( = 3.715, = 0.001) in the second. And (3) the cases of falling between two assessments were not significant different ( = 0.073, = 0.787) in the patients with vertigo. It is concluded from this study that the foam posturography has high test-retest reliability to assess the postural balance in the patients with vertigo in stable state, indicating the foam posturography can be used as the valid means to assess the improvement of postural balance for patients with vertigo in the vestibular rehabilitation therapy.

标题 作者 时间 类型 操作

Dialdehyde cellulose nanocrystal cross-linked chitosan foam with high adsorption capacity for removal

期刊论文

Removal of copper by modified chitosan adsorptive membrane

Xiaoshuai LIU, Zihong CHENG, Wei MA

期刊论文

Correction to: Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlled

期刊论文

Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Yao NIE,Shubo DENG,Bin WANG,Jun HUANG,Gang YU

期刊论文

Facile strategy for carbon foam fabrication with lignin as sole feedstock and its applications

期刊论文

Effect of IL-10 on formation of foam cell induced by ox-LDL

WANG Fei, DAI Yalei, XU Ting, XU Bo, WANG Kaifeng

期刊论文

Stability of three-dimensional printable foam concrete as function of surfactant characteristics

期刊论文

The role of single deformed bubble on porous foam tray with submerged orifices on the mass transfer enhancement

期刊论文

An antifouling catechol/chitosan-modified polyvinylidene fluoride membrane for sustainable oil-in-water

Shanshan Zhao, Zhu Tao, Liwei Chen, Muqiao Han, Bin Zhao, Xuelin Tian, Liang Wang, Fangang Meng

期刊论文

Solvent-free mechanochemical mild oxidation method to enhance adsorption properties of chitosan

期刊论文

Anthocyanins/chitosan films doped by nano zinc oxide for active and intelligent packaging: comparison

期刊论文

Nano-hydroxyapatite formation via co-precipitation with chitosan-g-poly(

Yang YU, Hong ZHANG, Hong SUN, Dandan XING, Fanglian YAO

期刊论文

NiFeRuOx nanosheets on Ni foam as an electrocatalyst for efficient

期刊论文

Chitosan/polyethylene glycol impregnated activated carbons: Synthesis, characterization and adsorption

Ehsan Salehi, Fereshteh Soroush, Maryam Momeni, Aboulfazl Barati, Ali Khakpour

期刊论文

Reliability of foam posturography in assessment of postural balance in the patients with vertigo

LIU Bo, KONG Weijia

期刊论文