FIBERS AND POLYMERS
·
2017
·Vol. 18
·期 6
·1025-1030
·
IF 1.113
Gao Zhe,Jiang Gaoming,Ma Pibo
Building proton transfer channel is an important strategy to optimize the proton transfer process of the proton exchange membrane (PEM). In this work, sulfonated pre-oxidized nanofibers were prepared by solution blowing of polyacrylonitrile (PAN) nanofibers followed by pre-oxidization and sulfonating, and the nanofibers were composited with SPEEK to enhance its performance as PEM. The results of the proton conductivity verified that the employment of sulfonated pre-oxidized nanofibers improved the proton conductivity. Meanwhile, the introduction of the sulfonated pre-oxidized nanofibers realized the upgrades of the thermostability and water absorbency of the membrane, and led to the decrease of the swelling property and methyl alcohol’s permeability of the material. It is indicated that the composite membrane is promising materials for PEM fuel cells.
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FUEL
·
2016
·
IF 3.611
Junmei Wang,Zehui Zhang,Shiwei Jin,Xizhou Shen
Catalytic conversion of carbohydrates into valuable chemical and liquid fuels has received considerable attention in recent years. In this study, sulfonic acid-functionalized ordered mesoporous carbon (OMC-SO 3 H) was prepared and well characterized by physical techniques such as TEM, nitrogen physisorption measurements and XRD. The as-prepared OMC-SO 3 H was then used for the acid-catalyzed conversion of fructose based carbohydrates into 5-hydroxylmethylfurfan (HMF) or 5-ethoxymethylfurfural (EMF). Due to the high surface area and high acidity, the OMC-SO 3 H catalyst showed a comparable catalytic performance as the homogeneous catalysts. The dehydration of fructose over the OMC-SO 3 H catalyst produced a high HMF yield of 89.4% in DMSO at 120 °C within 30 min. The one-pot transformation of fructose carbohydrates were also smoothly performed, affording EMF yields of 55.7%, 53.6% and 26.8% from fructose, iuline and sucrose after 24 h at 140 °C, respectively. Furthermore, the OMC-SO 3 H catalyst can be reused and no apparent loss of the activity was observed.
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JOURNAL OF MOLECULAR LIQUIDS
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2017
·
IF 3.648
Li-rong Nie,Shun Yao,Bing Dong,Xin-lu Li,Hang Song
In this paper, five novel cholinium-based organic magnetic ionic liquids (MILs) were synthesized. The carbon chain links to the nitrogen atom from cationic nucleus. The MILs were comprehensively identified by FT-IR, HPLC, UV–Vis, 1 H NMR and ESI-MS. The MILs have interesting performance to form aqueous two-phase system and can respond to the external magnetic field after the formation of aqueous two-phase system, which can assists magnetically phase separation. The magnetic susceptibility of the MILs was measured at 298 K. Other physical properties such as conductivities, acidity and density were measured in range of 278.15 K to 323.15 K for further application investigation. Satisfactory results were obtained after the data of physical properties were correlated. Based on the measurements and correlations above, some discussions were carried out, including the ion association and ion diffusion , the influences of MILs carbon chain and temperature on the molar conductivity , the influences of the cation size on the molar volume , acidity variation of the MILs.
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Polymers
·
2024
·Vol. 16
·期 21
·2958
·
IF 4.7
Jianrong Xia,Haobin Wu,Kaidong Chen,Yanling Li,Xin Lu,Sibo Ding,Xuelin Zheng
This study successfully developed a bio-based, photocurable, anionic–nonionic dual-functional chain extender, and sulfonated cardanol-based polyethylene glycol (SCP), derived from renewable resources—cardanol and polyethylene glycol—for application in waterborne polyurethane dispersions (WPUDs). Utilizing SCP as a chain extender, WPUDs were prepared through a typical acetone process with poly(butylene adipate) (PBA), isophorone diisocyanate (IPDI), and ethylene diamine (EDA) at a constant NCO/OH ratio of 1:1. This research focused on the effects of polyethylene glycol molecular weight and SCP dosage on the particle size, stability, and film-forming properties of the WPUD. Optimal dispersion stability and film-forming performance were achieved with a polyethylene glycol molecular weight of 1500 and a PBA to SCP molar ratio of 4:1, yielding a particle size of 0.326 ± 0.010 μm and excellent storage stability over six months. The resulting WPU coatings exhibited a tensile strength of 11.4 MPa, which increased to 16.8 MPa after UV irradiation owing to the formation of a semi-interpenetrating network via the photopolymerization of cardanol’s unsaturated side chains. UV cross-linking also enhanced water resistance, reducing the water absorption rate (WAR) from 18.68% to 4.21% and the water vapor transmission rate (WVTR) from 6.59 × 10−5g·m⁻¹·Pa⁻¹·d⁻¹ to 2.26 × 10⁻⁵ g·m⁻¹·Pa⁻¹·d⁻¹, while also improving thermal stability. These findings demonstrate that SCP offers a sustainable and effective solution for developing high-performance WPU coatings.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Zhenyu Li,Huifeng Deng,Yu Jiang,Jianbin Ju,Xiaowen Huang,Lang Zhang,Guihua Ruan,Zhengyi Chen,Yipeng Huang
Portable fluorescence-based Cs + radionuclide sensing has received great concerns yet challenged by interference in complex sample matrices. Herein, a reliable method was established by in situ converting the preconcentrated Cs + to CsPbBr 3 perovskite nanocrystals in mesoporous silica modified with dibenzo 24-crown-8 ethers (DB24C8E-SiO 2 ), which combined the selective extraction of Cs + with in situ fluorescence derivatization to achieve good anti-interference ability. The high adsorption capacity (49.5 mg g −1 ) of DB24C8E-SiO 2 for Cs + and elution-free operation enabled enrichment factor up to 4500, which was conducive to reducing the limit of detection (LOD) for Cs + . By this method, the fluorescence intensity linearly increased with the Cs + concentration from 0.050 μg mL −1 to 100 μg mL −1 with an LOD of 0.017 μg mL −1 (S/N = 3). The concentration of Cs + in seawater sample was detected to be 0.056 μg mL −1 . The recoveries of Cs + in spiked samples remained above 88.90 % and the relative standard deviations were less than 12.06 %. In addition, the relative errors of this method were within ±13.2 % compared with the result from atomic absorption spectrometry. The study demonstrated the high potential of the method for removal and portable detection of Cs + .
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Lingxiao He,Ning Ma,Zhengyun Liang,Sidan Zhao,Jiaming Yan,Hanchen Lin,Chaoqun You,Lingchao Cai,Fei Wang
Matrine is a type of alkaloid found in plants, exhibiting a wide range of biological and pharmacological activities. The process of separating and purifying matrine poses challenges due to its low concentration and frequent presence in mixtures during raw extraction. This work aims at synthesizing suitable adsorbents for efficient separation and purification of matrine from plant materials. The sulfonated cellulose nanocrystals/sodium alginate beads (SCNCs/SA) were synthesized by the ionic gelation method, characterized and investigated for the adsorption of matrine from water. The equilibrium adsorption capacity of SCNCs/SA beads for matrine at 298 K was approximately 55.66 mg/g. The adsorption enthalpy, entropy, and free energy of matrine on the SCNCs/SA beads were evaluated, indicating that the adsorption process was spontaneous, exothermic, and primarily driven by physisorption. 95 % of the adsorption equilibrium could be achieved within 60 min, and approximately 20 bed volumes of an 80 % (v/v) ethanol aqueous solution for effective recovery. The adsorption isotherms are analyzed using both Langmuir and Freundlich models, the kinetic of adsorption using the pseudo-first-order and pseudo-second-order models, and the breakthrough curves using four breakthrough models. These results suggested that the rapid adsorption and effortless regeneration render SCNCs/SA beads as promising adsorbents for the efficient adsorption and separation of matrine from plants.
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Polymers
·
2024
·Vol. 16
·期 11
·1555
·
IF 4.7
Sheng Yan,Yunren Qiu
The most prevalent type of hemodialysis membrane is polysulfone (PSf). However, due to inadequate biocompatibility, it significantly compromises the safety of dialysis for patients. In this study, we modify the surface of the PSf membrane with 2,4-dihydroxybenzophenone (DBPh) groups to serve as anchoring sites during UV irradiation. Subsequently, a tailored sulfonated dihydroxy propyl chitosan (SDHPCS) is grafted onto the modified PSf membrane to compensate for the deficiencies in hydrophilic additives. The modified PSf membrane exhibits outstanding hydrophilicity and stability, as demonstrated by its characterization and evaluation. This paper focuses on investigating the interaction between platelet membrane formation, protein adsorption, and anticoagulant activity. The results show that the modified PSf membrane exhibits remarkable enhancement in surface hydrophilicity, leading to a significant reduction in protein and platelet adsorption as well as adhesion.
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MACROMOLECULES
·
2024
·
IF 5.1
Yunchao Zheng,Lidao Song,Minqi Liu,Wei Wei,Huiming Xiong
Electrophilic isothiocyanates and nucleophilic aziridines have been successfully copolymerized to produce polyisothioureas through either condensation or chain growth polymerization. Aziridine-derived zwitterionic intermediates (ZWIs) present in the polymerization have been identified unambiguously by employing real-time high-resolution mass spectrometry (HRMS) and time-evolving proton nuclear magnetic resonance spectra (1H NMR), which has been revealed to play critical roles in both copolymerization processes. The spontaneous condensation–polymerization is found to proceed readily via the ZWIs free of any initiator and catalyst, involving cationic polymerization to produce polyimine content. Alternatively, transformation of the condensation–polymerization into comparably fast chain growth polymerization can be achieved by introducing an anionic nucleophile to initiate and activate the ZWI served as the monomer herein, leading to well-defined fully alternating copolymers of the isothiourea repeat unit (−NC(═N)S−) with discrete chain ends, which is supported by the density functional theory (DFT) calculations. The DFT calculations also suggest that the formation of the ambiphilic ZWIs would be favored between the pairs of the nucleophilic aziridine with a higher energy of the highest occupied molecular orbital (HOMO) and the electrophilic isothiocyanate possessing a lower energy of the lowest unoccupied molecular orbital (LUMO), and the reactivity of the ZWI in the polymerization is influenced by its electronic structure.
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MOLECULES
·
2024
·Vol. 29
·期 8
·1832
·
IF 4.2
Pin Luo,Wei Liu,Zhangyao Ye,Yuyu Zhang,Zekun Zhang,Jing Yi,Rong Zeng,Shenyu Yang,Mei Tu
Diabetic wound healing is a significant clinical challenge because abnormal immune cells in the wound cause chronic inflammation and impair tissue regeneration. Therefore, regulating the behavior and function of macrophages may be conducive to improving treatment outcomes in diabetic wounds. Herein, sulfated chitosan (26SCS)-containing composite sponges (26SCS-SilMA/Col-330) with well-arranged layers and high porosity were constructed based on collagen and silk fibroin, aiming to induce an appropriate inflammatory response and promote angiogenesis. The results indicated that the ordered topological structure of composite sponges could trigger the pro-inflammatory response of Mφs in the early stage, and rapid release of 26SCS in the early and middle stages (within the concentration range of 1–3 mg/mL) induced a positive inflammatory response; initiated the pro-inflammatory reaction of Mφs within 3 days; shifted M1 Mφs to the M2 phenotype within 3–7 days; and significantly up-regulated the expression of two typical angiogenic growth factors, namelyVEGFandPDGF-BB, on day 7, leading to rapid HUVEC migration and angiogenesis. In vivo data also demonstrated that on the 14th day after surgery, the 26SCS-SilMA/Col-330-implanted areas exhibited less inflammation, faster re-epithelialization, more abundant collagen deposition and a greater number of blood vessels in the skin tissue. The composite sponges with higher 26SCS contents (the (5.0) 26SCS-SilMA/Col-330 and the (7.5) 26SCS-SilMA/Col-330) could better orchestrate the phenotype and function of Mφs and facilitate wound healing. These findings highlight that the 26SCS-SilMA/Col-330 sponges developed in this work might have great potential as a novel dressing for the treatment of diabetic wounds.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2020
·
IF 4.389
Sheng Yan,Ming-Ming Tu,Yun-Ren Qiu
Polysulfone (PSf) membrane is widely employed in blood purification fields, but the blood compatibility of PSf membrane is not adequate. To improve the hemocompatibility of PSf membrane, 4-(chloromethyl)benzoic acid (CMBA) and sulfonated hydroxypropyl chitosan (SHPCS) were grafted onto PSf membrane surface. In our strategy, CMBA was firstly grafted on the PSf membrane surface through the Friedel-Crafts alkylation reaction, and the product was named BAPSf membrane. Then, SHPCS was grafted onto the BAPSf membrane surface by esterification , and the product was named SHPCS-BAPSf membrane. The effects of temperature and reaction time on the productivity of BAPSf and the grafting density of carboxyl and the effects of reaction time on the grafting density of SHPCS grafted onto the BAPSf membrane surface were studied. The SHPCS-BAPSf membranes are investigated by ATR-FTIR, XPS , contact angle measurements and evaluated by blood compatibility in vitro. The results reveal that the hydrophilicity of SHPCS-BAPSf membranes were grealy improved and the evaluation of protein adsorption , hemolysis test, platelet adhesion plasma recalcification time(PRT), activated partial thromboplastin time(APTT), prothrombin time(PT) and thrombin time(TT) confirmed that the SHPCS-BAPSf membranes have remarkable blood compatibility.
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Polymers
·
2024
·Vol. 16
·期 15
·2208
·
IF 4.7
Kun Cai,Jinzhu Yu,Wenjun Tan,Cong Gao,Zili Zhao,Suxin Yuan,Jinghui Cheng,Yajie Yang,Ye Yuan
Nafion membranes are widely used as proton exchange membranes, but their proton conductivity deteriorates in high-temperature environments due to the loss of water molecules. To address this challenge, we propose the utilization of porous aromatic frameworks (PAFs) as a potential solution. PAFs exhibit remarkable characteristics, such as a high specific surface area and porosity, and their porous channels can be post-synthesized. Here, a novel approach was employed to synthesize a PAF material, designated as PAF-45D, which exhibits a specific surface area of 1571.9 m2·g−1and possesses the added benefits of facile synthesis and a low cost. Subsequently, sulfonation treatment was applied to PAF-45D in order to introduce sulfonic acid groups into its pores, resulting in the formation of PAF-45DS. The successful incorporation of sulfonic groups was confirmed through TG, IR, and EDS analyses. Furthermore, a novel Nafion composite membrane was prepared by incorporating PAF-45DS. The Nyquist plot of the composite membranes demonstrates that the sulfonated PAF-45DS material can enhance the proton conductivity of Nafion membranes at high temperatures. Specifically, under identical film formation conditions, doping with a 4% mass fraction of PAF-45DS, the conductivity of the Nafion composite membrane increased remarkably from 2.25 × 10−3S·cm−1to 5.67 × 10−3S·cm−1, nearly 2.5 times higher. Such promising and cost-effective materials could be envisioned for application in the field of Nafion composite membranes.
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MOLECULES
·
2024
·Vol. 29
·期 18
·4286
·
IF 4.2
Xin Wei,Jie Li,Xiangfei Geng,Di Niu,Zhenjie Wei,Chenxu Wang,Ziqi Sun,Yangchun Xie
In this paper, a series of tetrameric surfactants (4CnSAZs,n= 12, 14, 16) endowed with zwitterionic characteristic were synthesized by a simple and convenient method and their structures were characterized by FT-IR,1H NMR and elemental analysis. Their physicochemical properties were studied using the Wilhelmy plate method, fluorescence spectra and dynamic light scattering technique. 4CnSAZs have higher surface activities and tend to adsorb at the air/water surface rather than self-assembling in aqueous solution. The thermodynamic parameters obtained from surface tension measurements show that both processes of adsorption and micellization of 4CnSAZs are spontaneous and that the micellization processes of 4CnSAZs are entropy-driven processes. Both adsorption and micellization of 4CnSAZs are inclined to occur with the increase of alkyl chain length or temperature. For 4C12SAZs, there are only small-size aggregates (micelles), while the large aggregates (vesicles) are observed at the alkyl length of 4CnSAZs of 14 or 16. This shows that the alkyl chain length for oligomeric surfactants has a greater sensitivity for aggregate growth. The aggregate morphologies obtained from the calculated values of critical packing parameter (p) for 4C14SAZs and 4C16SAZs can be supported by the DLS measurement results. The test results obtained by the separation-water-time method show that 4CnSAZs have good emulsification performance and that the prepared emulsions appear to exit in the form of multiple emulsions. In addition, 4CnSAZs have good antibacterial activities againstEscherichia coli(E. coli) and Staphylococcus aureus (S. aureus). The present study reveals the unique behavior of a zwitterionic tetrameric surfactant and may give new insights into molecular design and synthesis of a high degree of surfactants with different structure characteristics for potential application in various industrial fields.
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