JOURNAL OF MOLECULAR LIQUIDS
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2019
·
IF 4.561
Junyan Wu,Hemin Gao,Diandian Shi,Yufei Yang,Yadong Zhang,Weixia Zhu
Nine novel cationic gemini surfactants containing both amide and ester groups were synthesized through a three-step reaction. These surfactants have the general formula of C n H 2n+1 OOCCH 2 N + (CH 2 ) 2 -(CH 2 ) 3 -NHOC-(CH 2 ) m -CONH-(CH 2 ) 3 -N + (CH 2 ) 2 CH 2 COOC n H 2n+1 (with n = 8, 10, 12 and m = 2, 3, 4), named BEQA-n, PEQA-n and HEQA-n (B, P, H correspond to surfactants of m = 2, 3, 4 and n = 8, 10, 12, respectively). Chemical structures, surface activity, cleavable properties, electrolytes tolerance, foam properties and antibacterial activity of these surfactants were successively investigated. The results show that the surfactants have lower critical micelle concentration (CMC) than traditional monomer surfactants. The values of CMC and the degree of counter ion dissociation (α) depend on the lengths of hydrophobic chain and spacer. The values of Krafft temperatures (K t < 0 °C) and the standard Gibbs free energy (∆G 0 mic < 0) indicate that all surfactants have good water solubility and micelle-forming ability. The simultaneous presence of the amide and ester groups makes these surfactants have good hydrolytic ability in both basic and the acidic solutions. In addition, the surfactants exhibit greater electrolyte tolerance to NaCl than CaCl 2 . It is worth mentioning that EQA-8 and PEQA-12 have 200 g/L NaCl tolerance. Moreover, all of the surfactants have certain antibacterial activity against Gram-positive bacteria (S. aureus ATCC 25923) and Gram-negative bacteria (E. coli ATCC 25922), and the surfactants with hydrophobic chain length n = 10 have the strongest antibacterial activity.
研究领域:
化学
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材料科学
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微生物学
·
表面化学
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DOI
高影响因子
JOURNAL OF SURFACTANTS AND DETERGENTS
·
2017
·Vol. 20
·期 3
·565-576
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IF 1.45
Lai Lu,Mei Ping,Wu Xiao-Mei,Cheng Li,Ren Zhao-Hua,Liu Yi
The dynamic interfacial properties and dilational rheology of gemini sulfonate surfactant (SGS) and its mixtures with quaternary ammonium bromides (DTAB, CTAB) at the air–water interface were investigated using drop shape analysis. Results suggest that the adsorption process of these surfactants is diffusion-controlled at dilute concentrations, whereas the adsorption mechanism gradually shifts to a mixed kinetic-diffusion control with increasing surfactant concentration. The mixed surfactant system possesses the best surface activity when the molar ratios of SGS/DTAB and SGS/CTAB mixtures are 9:10. The formation of catanionic complexes shields the electrostatic repulsion between surfactant molecules and lowers the electrostatic adsorption barrier. Therefore, SGS/DTAB and SGS/CTAB mixtures exhibit higher adsorption rates than either component alone. The effects of oscillating frequency and surfactant concentration on the surface dilational properties of SGS, DTAB, CTAB, SGS/DTAB, and SGS/CTAB mixtures were also determined. As the oscillating frequency increases, the dilational elasticity of these surfactants gradually increases. The dilational elasticity peaks at a certain concentration, which is less than the critical micelle concentration (CMC). Results show that the dilational elasticity of SGS/DTAB and SGS/CTAB mixtures is higher than that of either component, resulting from the formation of a denser monomolecular adsorption layer at the air–water interface. Our study provides a basis for understanding the interaction mechanism of catanionic surfactant mixtures containing Gemini surfactant at the air–water interface.
研究领域:
化学
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表面科学
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胶体与界面科学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Juanjuan Fu,Yinglian Zhu,Fansheng Cheng,Shuangling Zhang,Tiantian Xiu,Yue Hu,Shuo Yang
For preparing stable water-in-oil-in-water emulsion, the role of nanoparticles in stabilizing the interface is very important. In this study, chitosan hydrochloride-carboxymethyl chitosan (CHC-CMC) nanoparticles were prepared considering electrostatic interactions; then the emulsion was prepared and the stability characteristics in presence of NaCl (0–200 mmol/L) and 30 d storage were studied. CHC-CMC nanoparticles (261 nm) were obtained when the CHC: CMC ratio was 1:2. CHC-CMC formation was verified by FT-IR when a new peak appeared at 1580 cm −1 ; W 2 contained 2 wt % CHC-CMC and W 1 contained 1 wt % sodium alginate , the creaming index (81.6 %) was higher for the emulsions than Tween 80 (67.4 %) after 30 d. Confocal laser scanning microscopy confirmed the double microstructures, in contrast to the collapse with Tween 80, because the CHC-CMC nanoparticles were densely adsorbing on the oil-water interface. This indicates that CHC-CMC has a stronger ability to stabilize W 1 /O/W 2 emulsion than Tween 80.
研究领域:
材料科学
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胶体与表面化学
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纳米技术
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食品科学
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DOI
高影响因子
ACS Catalysis
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2024
·
IF 11.3
Kemin Lv,Xiaozhou Li,Kequan Chen,Bin Wu,Bingfang He,Gerhard Schenk
Processive endoglucanase is a typical bifunctional biocatalyst for cellulose degradation. A GH5 processive endoglucanase from Bacillus subtilis BS-5 was previously identified and shown to exhibit highly efficient catalytic performance. To further augment its catalytic efficiency, both consensus mutagenesis and loop engineering were applied. Compared to the wild-type enzyme, a variant (M3-1) with the four point mutations, i.e., K91I, A198T, Q237D, and V240P, exhibits an 8.5- and 4.8-fold increase in catalytic efficiency toward the soluble substrate carboxymethyl cellulose-Na (CMC) and the insoluble phosphoric acid-swollen cellulose (PASC), respectively. Molecular dynamics simulations were employed to elucidate the conformational changes that led to the enhanced catalytic efficiency. Structural superpositions suggest that the mutations cause a swing in loop 230–241, which in turn affects enzyme–substrate affinity and recognition. Residues K91 and A198 are located distal from the active site. The mutations K91I and A198T influence key amino acids within the active pocket through residue interaction networks in the protein. Furthermore, dynamic cross-correlation matrices (DCCMs) indicate that variant M3-1 possesses a conformation that is more favorable than that of the wild-type enzyme, promoting an increased frequency of interactions between active site residues and substrate molecules and thereby enhancing catalytic efficiency. The combined results provide valuable insights into the rational design and engineering of processive endoglucanases and other glycoside hydrolases, enabling the development of improved enzymatic catalysts for biotechnology applications.
研究领域:
生物催化
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酶工程
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生物化学
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分子生物学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
·
IF 8.025
Yu Guo,Rongbo Guo,Xiaoshuang Shi,Shujuan Lian,Qiannan Zhou,Ying Chen,Weifeng Liu,Wei Li
In this study, cellulose-based superabsorbent hydrogel was synthesized from sodium carboxymethyl cellulose (CMC-Na), acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to enhance its water absorbency and salt tolerance for soil-conditioning applications in areas suffering from drought and soil salinization. Superabsorbent hydrogels (SHs) were prepared by CMC-Na and AMPS successfully, using chemical graft technology. Structure, morphology, thermal stability , and water absorbency of SHs were deduced. The cellulose-based hydrogel showed a high salt tolerance that the maximum water absorbency reached 604 and 119% in distilled water and saline water, respectively. The swelling behavior in aqueous solvents indicated that the water absorption of hydrogels was improved with the increasing ratio of CMC-Na. All SHs exhibited adsorption of nitrogen with the maximum adsorption of ammonia nitrogen 30 mg·g −1 and the presence of hydrogels could slow down the loss of nutrients in the soil. This study provided a feasible strategy that AMPS was substituted by CMC-Na to synthesize SHs with strong water absorbency and high salt tolerance which could be efficiently applied in agriculture as a soil conditioner.
研究领域:
材料科学
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环境科学
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农业科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Yanqin Wang,Yu Zhu,Xuehui Zhang,Fengbo Zhu,Yi-Xian Qin,Weiyi Chen,Qiang Zheng
It is quite urgent to develop a smart and high through-put confidential information storage, protection, and display platform based on the fluorescent hydrogels that could exhibit diverse fluorescent variation behavior during each stimulus-based shape memory and recovery process. Herein, it proposed an effective approach to develop a novel fluorescent composite gel with Fe 3+ , pH, and glucose-dependent diversity fluorescence variation and shape memory behavior. For this composite gel system, based on the reversible coordination interactions between Fe 3+ and carboxylic acid groups of carboxymethyl cellulose (CMC), boric acid groups of carbon dots (CDs), and hydroxyl groups of PVA , it can stabilize and memorize the temporary shapes under the stimulus of Fe 3+ and pH, respectively. Meanwhile, the fluorescence of the CDs within the gels can also exhibit diversity variation behaviors during each shape recovery process. Furthermore, the compositions of the composite gel were optimized to realize relatively high efficiency of shape recovery and fluorescence variation under each type of stimulus. In summary, this study presented a universal strategy for multi-shape memory hydrogels with diverse fluorescence variation properties which exhibited prominent prospective in the field of information encryption with high-level security.
研究领域:
材料科学
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化学
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纳米技术
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信息安全
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
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IF 4.9
Ruping Huang,Jingchun Zhang,Qiqi Wang,Haoyuan Chen,Yiyue Shen,Yupei Deng,Guowei Wang,Linghua Zhuang
One functional hydroxyl group-containing anionic surface active ionic liquids (SAILs), 1-(3-hydroxypropyl)-3-methylimidazolium dodecyl sulfate ([MPmim][DS]) and 1-(3-hydroxypropyl)-3-butylimidazolium dodecyl sulfate ([MPbim][DS]) were synthesized and characterized with 1 HNMR, 13 CNMR, FT-IR spectroscopy, thermogravimetric analysis (TGA), and elemental analysis . The critical micellar concentration (CMC) values of [MPmim][DS] and [MPbim][DS] were obtained through measurements of surface tension and electrical conductivity . The capability of [MPmim][DS] and [MPbim][DS] to form microemulsions was assessed. The influence of the hydroxyl group of imidazolium cation on microemulsion formulation was elucidated using Density functional theory (DFT) simulations. Critical micellar concentration (CMC) values for [MPbim][DS] and [MPmim][DS] are 0.51 mmol/L and 0.99 mmol/L, respectively. The micellization processes of [MPbim][DS] and [MPmim][DS] are spontaneous, endothermic, and entropy-driven. [MPmim][DS] or [MPbim][DS] as surfactant , ethyl laurate microemulsions are formulated. The single-phase region area (S ME ) percent of ethyl laurate microemulsions are 60% and 66%. The single-phase region area percent of different microemulsions follows the trend: [MPbim][DS] > [MPmim][DS]. Introducing the functional hydroxyl group into the imidazolium cation significantly expands the S ME area of microemulsions. DFT simulations are employed to analyze hydrogen bonding and electronic energy interactions among cations, DS anion, [MPmim][DS], [MPbim][DS], and ethyl laurate. Two types of hydrogen bonds are formed in [MPmim][DS] or [MPbim][DS], as C-H…O, and O-H…O. In [MPmim][DS], the hydroxyl group of imidazolium cation participates in the formation of a strong hydrogen bond with DS anion, exemplified by strong hydrogen bond O18-H19…O64 (1.972 Å). These advancements offer critical insights into the design of surface active ionic liquids , enhancing their functional properties and broadening the potential for innovative microemulsion applications in various industries.
研究领域:
胶体科学
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表面化学
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材料科学
·
物理化学
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产品关联
DOI
高影响因子
JOURNAL OF SURFACTANTS AND DETERGENTS
·
2019
·Vol. 22
·期 3
·411-419
·
IF 1.672
Ruijuan Wang,Dong Wang,Zhigang Yin,Xuzhao Yang,Quan Liu
The carboxylic acid-type Gemini surfactant (CGS12) was synthesized, and its micellization in aqueous solution at different pH values at 25.0 °C was investigated. The results show that the critical micelle concentration (CMC) of CGS12 at different pH values is only 10 −6 order of magnitude, and the pH has little effect on the CMC. Moreover, the interaction of CGS12 with amino acid surfactant of sodium N-lauroyl sarcosinate (SLS) at 25.0 °C and pH 7.0 was investigated using surface tension, dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM), and Ross–Miles foam measurements. The CGS12/SLS mixture shows a low CMC, and as a whole the CMC value becomes smaller with increasing molar fraction of CGS12 (X CGS12 ). Under different X CGS12 , the mixtures form soluble aggregates with different hydration radii ( R h ). Moreover, the mixture aggregates are mainly in the form of vesicles. The foaming height of CGS12 is worse than that of SLS, but the CGS12/SLS mixture has good foaming stability. This work reveals that the surfactant mixture has good surface activity and good foam stability.
研究领域:
表面活性剂化学
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胶体科学
·
物理化学
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产品关联
DOI
高影响因子
JOURNAL OF CONTROLLED RELEASE
·
2022
·
IF 11.467
Chao Li,Liwen Yuan,Xuehua Zhang,Aoxue Zhang,Yuanhu Pan,Yulian Wang,Wei Qu,Haihong Hao,Samah Attia Algharib,Dongmei Chen,Shuyu Xie
The stomach acid degradation, mucus clearance and intestinal epithelial impermeability severely limit the oral delivery of polypeptide drugs. To simultaneously address the three major barriers, novel self-assembled core-shell nanosystems (CA-NPs) were designed. The fabricated shell of citric acid cross-linked carboxymethyl cellulose (CA-CMC) wrapped on core nanoparticles (HA-NPs) maintained the integrity of CA-NPs in the stomach. When CA-NPs passed through the stomach, the CA-CMC shell was gradually degraded to release the core HA-NPs in the intestine. HA-NPs with numerous hydrophilic groups and mannose side chains rapidly penetrated through the mucus layer and efficiently transcellular transported via the glucose transporter (GLUT)-mediated and paracellular transport through reversible opening of tight junctions (TJs) by CA-CMC. The oral bioavailability and therapeutic effects of CA-NPs-loaded polypeptide colistin against Escherichia coli ( E. coli ) bacteremia in mice were significantly increased compared with the native colistin, respectively. Good safety was observed following oral daily delivery for 14 consecutive days. Thus, CA-NPs may offer a promising strategy for the oral delivery of polypeptide drugs.
研究领域:
药学
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纳米技术
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药物递送系统
·
生物医学工程
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DOI
PubMed
高影响因子
Case Studies in Thermal Engineering
·
2024
·
IF 6.4
Wenjun Zhao,Zhisheng Xu,Long Yan,Guoqing Niu
The research of short-chain fluorocarbon surfactants is crucial in effectively and environmentally extinguishing petrochemical fires. In this study, a short-chain fluorocarbon surfactant named 2 H ,2 H -perfluorooctanoic acid sodium salt (PFH-CA) was synthesized, and then characterized its chemical structure, thermal stability, surface activity, and foam property. Subsequently, PFH-CA was compounded with hydrocarbon surfactants including sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride (DTAC), and N , N -dimethyldodecylamine- N -oxid (OB-2) at different molar ratios. The surface tension, interaction parameters, and foam property of the PFH-CA/hydrocarbon surfactant compounding systems were investigated. The analysis indicates that PFH-CA exhibits excellent surface activity and thermal stability concomitant with poor foam property. Introducing SDS, DTAC, and OB-2 enhances the foam performance and reduces the consumption of PFH-CA through synergistic interactions. Especially, PFH-CA/DTAC (1:4) system possesses the strongest interactions and the best performance, with critical micelle concentration ( CMC ) and surface tension at CMC ( γ CMC ) of 0.11 mmol/L and 20.90 mN/m, respectively. When concentration of PFH-CA exceeds 0.5 mmol/L, the foaming ability and foam stability stabilize at 30 cm and 90 %, respectively. The enhanced performance of PFH-CA/DTAC system is attributed to the electrostatic attraction between anionic and cationic surfactants, which facilitates the formation of micelles, subsequently leading to better surface activity and foam properties.
研究领域:
化学
·
材料科学
·
消防安全工程
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产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2023
·Vol. 34
·期 7
·2235-2247
·
IF 3.4
Jie Xu,Hongchun Li,Yongsheng Niu
In this study, a temperature sensitive graft carbon dioxide-based copolymer, poly (propylene oxide-co-carbon dioxide-co-allyl glycidyl ether)-poly (N-isopropylacrylamide)-polyethylene glycol monomethyl ether (PPAG-PNIPAm-mPEG) was synthesized by “Click Chemistry”. The hydrophobic main chain, PPAG, was prepared by the copolymerization of propylene oxide (PO) and allyl glycidyl ether (AGE). The branch chains include hydrophilic mPEG and temperature sensitive poly (N-isopropylacrylamide). The structure of the polymer was characterized by 1 H NMR and IR spectroscopy. Avermectin (AVE) was loaded into the nanoparticles to form PPAG-PNIPAm-mPEG@AVE nanoparticles. PPAG-PNIPAm-mPEG could self-assemble into nano-sized micelles in aqueous solution. And the size, zeta potential, critical micelle concentration (CMC) of PPAG-PNIPAm-mPEG nanoparticles can be altered by changing the lengths of the PNIPAm segments. The loading rate and encapsulation rate of PPAG-PNIPAm-mPEG@AVE were 36.98% and 89.98% respectively. The temperature sensitiveness of the nanomaterials was confirmed by DLS. The results show that temperature has a certain effect on the AVE release rate of PPAG-PNIPAm-mPEG@AVE in vitro. With the decrease of PNIPAm chain length, the AVE release rate decreases, and the contact angle of PPAG-PNIPAm-mPEG@AVE decreases compared with that of water.
研究领域:
高分子科学
·
药学
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纳米技术
·
药物递送系统
✓ 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）