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Control on self-assembly structures of rod-coil-rod (PANI)-(PEG)-(PANI) triblock copolymer

YANG Zhifang, WU Jingao, YANG Yingkui, ZHOU Xingping, XIE Xiaolin

《化学科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 85-88 doi: 10.1007/s11705-008-0003-6

摘要: The self-assembly behaviors of the rod-coil-rod (PANI)-(PEG)-(PANI) triblock copolymer are investigated in different solvents, such as -methyl-2-pyrrolidone (NMP), dimethyl formamide (DMF), ethanol and water. The effects of solvents, concentration and ultrasonic irradiation on self-assembly are discussed. The results indicate that the triblock copolymer forms particles, rods, fiber, networks and fiber bands in the above solvents, respectively. Especially, the triblock copolymer can form a multi-layer, tri-dimensional fibrous network and a petaline structure from the mono-layer fibrous network with the increase of its concentration in ethanol. Also, the ultrasonic irradiation has a great effect on the self-assembly of the triblock copolymer.

关键词: different     multi-layer     mono-layer     dimethyl formamide     concentration    

Ionic strength directed self-assembled polyelectrolyte single-bilayer membrane for low-pressure nanofiltration

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 699-708 doi: 10.1007/s11705-021-2093-3

摘要: Layer-by-layer assembly is a versatile technique for fabricating nanofiltration membranes, where multiple layers of polyelectrolytes are usually required to achieve reasonable separation performance. In this work, an ionic strength directed self-assembly procedure is described for the preparation of nanofiltration membranes consisting of only a single bilayer of poly(diallyldimethylammoniumchloride) and poly(sodium-4-styrenesulfoate). The influence of background ionic strength as well as membrane substrate properties on the formation of single-bilayer membranes are systematically evaluated. Such a simplified polyelectrolyte deposition procedure results in membranes having outstanding separation performance with permeating flux of 14.2 ± 1.5 L∙m–2∙h–1∙bar–1 and Na2SO4 rejection of 97.1% ± 0.8% under a low applied pressure of 1 bar. These results surpass the ones for conventional multilayered polyelectrolyte membranes. This work encompasses an investigation of ionic strength induced coiling of the polyelectrolyte chains and emphasizes the interplay between-polyelectrolyte chain configuration and substrate pore profile. It thus introduces a new concept on the control of membrane fabrication process toward high performance nanofiltration.

关键词: layer-by-layer self-assembly     single bilayer     nanofiltration membrane     desalination    

Enzyme-instructed self-assembly of peptides containing phosphoserine to form supramolecular hydrogels

Jie Zhou, Xuewen Du, Jiaqing Wang, Natsuko Yamagata, Bing Xu

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 509-515 doi: 10.1007/s11705-017-1613-7

摘要: Enzyme-instructed self-assembly (EISA) offers a facile approach to explore the supramolecular assemblies of small molecules in cellular milieu for a variety of biomedical applications. One of the commonly used enzymes is phosphatase, but the study of the substrates of phosphatases mainly focuses on the phosphotyrosine containing peptides. In this work, we examine the EISA of phosphoserine containing small peptides for the first time by designing and synthesizing a series of precursors containing only phosphoserine or both phosphoserine and phosphotyrosine. Conjugating a phosphoserine to the -terminal of a well-established self-assembling peptide backbone, (naphthalene-2-ly)-acetyl-diphenylalanine (NapFF), affords a novel hydrogelation precursor for EISA. The incorporation of phosphotyrosine, another substrate of phosphatase, into the resulting precursor, provides one more enzymatic trigger on a single molecule, and meanwhile increases the precursors’ propensity to aggregate after being fully dephosphorylated. Exchanging the positions of phosphorylated serine and tyrosine in the peptide backbone provides insights on how the specific molecular structures influence self-assembling behaviors of small peptides and the subsequent cellular responses. Moreover, the utilization of D-amino acids largely enhances the biostability of the peptides, thus providing a unique soft material for potential biomedical applications.

关键词: enzyme-instructed self-assembly     phosphoserine     phosphatase     supramolecular hydrogel    

Supramolecular self-assembly of two-component systems comprising aromatic amides/Schiff base and tartaric

Xin Wang, Wei Cui, Bin Li, Xiaojie Zhang, Yongxin Zhang, Yaodong Huang

《化学科学与工程前沿(英文)》 2020年 第14卷 第6期   页码 1112-1121 doi: 10.1007/s11705-019-1865-5

摘要: The gelating properties and thermotropic behaviors of stoichiometric mixtures of aromatic amides , and the aromatic Schiff base with tartaric acid (TA) were investigated. Among the three gelators, -TA exhibited superior gelating ability. Mixture -TA exhibits a smectic B phase and an unidentified smectic mesophase during both heating and cooling runs. The results of Fourier transform infrared spectroscopy and X-ray diffraction revealed the existence of hydrogen bonding and - interactions in -TA systems, which are likely to be the dominant driving forces for the supramolecular self-assembly. Additionally, it was established that all of the studied gel self-assemblies and mesophases possess a lamellar structure. The anion response ability of the tetrahydrofuran gel of -TA was evaluated and it was found that it was responsive to the stimuli of F , Cl , Br , I , AcO .

关键词: supramolecular self-assembly     organogel     liquid crystal     tartaric acid     hydrogen bond    

Shrink-induced graphene sensor for alpha-fetoprotein detection with low-cost self-assembly and label-free

Shota SANDO, Bo ZHANG, Tianhong CUI

《机械工程前沿(英文)》 2017年 第12卷 第4期   页码 574-580 doi: 10.1007/s11465-017-0485-3

摘要:

Combination of shrink induced nano-composites technique and layer-by-layer (LbL) self-assembled graphene challenges controlling surface morphology. Adjusting shrink temperature achieves tunability on graphene surface morphology on shape memory polymers, and it promises to be an alternative in fields of high-surface-area conductors and molecular detection. In this study, self-assembled graphene on a shrink polymer substrate exhibits nanowrinkles after heating. Induced nanowrinkles on graphene with different shrink temperature shows distinct surface roughness and wettability. As a result, it becomes more hydrophilic with higher shrink temperatures. The tunable wettability promises to be utilized in, for example, microfluidic devices. The graphene on shrink polymer also exhibits capability of being used in sensing applications for pH and alpha-fetoprotein (AFP) detection with advantages of label free and low cost, due to self-assembly technique, easy functionalization, and antigen-antibody reaction on graphene surface. The detection limit of AFP detection is down to 1 pg/mL, and therefore the sensor also has a significant potential for biosensing as it relies on low-cost self-assembly and label-free assay.

关键词: graphene     self-assembly     shrink polymer     AFP     label-free     biosensor    

Two-dimensional self-assembly of melem and melemium cations at pH-controlled aqueous solution–Au(111)

Shinobu Uemura,Kenki Sakata,Masashi Aono,Yusuke Nakamura,Masashi Kunitake

《化学科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 294-300 doi: 10.1007/s11705-016-1564-4

摘要: Two-dimensional self-assembly of melem at pH-controlled aqueous solution-Au(111) interfaces has been investigated by electrochemical scanning tunneling microscopy. In the solutions with pH>p of melem, two ordered self-assembled structures (honeycomb and close-packed structures) and one disordered fibrillar structure were observed as a function of the surface coverage of melem controlled by the electrode potential. In contrast, in the acidic solution with pH

关键词: self-assembly     scanning tunneling microscopy     electrochemistry     structural phase transition     melem    

Effects of solvents and temperature on spherulites of self-assembled phloroglucinol tristearate

Yawen Yao, Sabine Rosenfeldt, Kai Zhang

《化学科学与工程前沿(英文)》 2020年 第14卷 第3期   页码 389-396 doi: 10.1007/s11705-019-1911-3

摘要: Herein, phloroglucinol tristearate (PhgTS) was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains. Spherulites of crystallized PhgTS from four solvents under diverse conditions were analyzed in detail and their formation process was studied. Maltese cross is shown by PhgTS spherulites obtained from aprotic solvents via polarized optical microscopy. In comparison, no Maltese cross can be observed from branch-like crystals formed from protic solvents. Independent on the microscaled morphology, lamellae were found to be the basic blocks constructing both PhgTS spherulites and branch-like crystals, which were formed predominantly by stacked PhgTS molecules. Although differential characters of the solvents did not affect the formation of lamellas, the solvents played a crucial role in the formation of self-assembled microscaled morphologies. In particular, the morphologies of spherulites were strongly affected by the concentration of PhgTS solutions, surrounding temperature and evaporation rate of solvents. Generally, a higher concentration of PhgTS led to more homogeneous spherulites, a lower evaporation rate resulted in more compact spherulites, and a higher surrounding temperature generated preferentially more ring-banded spherulites of PhgTS.

关键词: phloroglucinol     tristearate     aprotic and protic solvent     self-assembly     spherulites    

The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1101-1113 doi: 10.1007/s11705-021-2095-1

摘要: Nanoparticles with high surface energy and chemical activity have drawn substantial attention in petroleum industry. Recently, Janus nanoparticles exhibited tremendous potential in enhanced oil recovery (EOR) due to their asymmetric structures and properties. In this study, a series of amphiphilic pseudo-Janus@OTAB (PJ@C18) nanoparticles with different concentrations of stearyltrimethylammoium bromide (OTAB) were successfully fabricated. The structures and properties of PJ@C18 were characterized by Fourier transform infrared spectroscopy and ζ-potential measurements. Based on the emulsification experimental results, the interaction models and the self-assembly behavior between hydrophilic nanoparticles (SiO2@NH2) and OTAB molecules at the oil/water interface were proposed, which was further confirmed via the measurements of the contact angle and dynamic interfacial tension. Interestingly, it was found that the change of pH value from 7.5 to 4.0 caused the type reversal of the PJ@C18-1000 stabilized Pickering emulsions. Furthermore, the PJ@C18-1000 stabilized Pickering emulsion system with excellent salt and temperature tolerances (10000 mg∙L–1, 90 °C) significantly improved the oil recovery in the single-tube (more than 17%) and double-tube (more than 25%) sand pack model flooding tests. The findings of this study could help to better understand the construction mechanism of pseudo-Janus silica/surfactant assembly and the potential application of PJ@C18-1000 stabilized Pickering emulsions for EOR.

关键词: Janus nanoparticles     surfactant     double phase inversion     self-assembly     enhanced oil recovery    

Fabrication and mechanical properties of single-wall carbon nanotubes and hyperbranched diazonium salt multilayers

LI Xinyang, FAN Pengwei, TUO Xinlin, WANG Xiaogong

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 286-290 doi: 10.1007/s11705-008-0058-4

摘要: Acidized single-wall carbon nanotubes (SWNTs) were fabricated into multilayers with a hyperbranched azobenzene-containing polymeric diazonium salt (PDAS) using the layer-by-layer adsorption technique. The fabrication process, multilayer thickness variation, multilayer surface morphology and the interaction between SWNTs and PDAS were monitored by UV-Vis absorption spectroscopy, optical ellipsometry, Atomic Force Microscopy, Scanning Electron Microscopy and Raman spectroscopy. Moreover, the nanomechanical properties of the multilayer films were measured by nanoindentation. All results show that SWNTs and PDAS can be fabricated into multilayers based on the cooperation of electrostatic absorption and chemical cross-linkage between SWNTs and PDAS. Further, this cooperation endows the SWNT/PDAS multilayer films with outstanding nanomechanical properties. The hardness and modulus are about 2.0GPa and 10.0GPa, respectively. Finally, the SWNT/PDAS multilayer film can be peeled off to be a free-standing film.

关键词: PDAS     layer-by-layer     interaction     cooperation     single-wall    

2,5-Dialkoxylphenyl-1,3,4-oxadiazoles as efficient organogelators and their self-assembling property

Zipei SUN,Xuelin DONG,Yan ZHAI,Ziyan Li,Yaodong HUANG

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 219-224 doi: 10.1007/s11705-014-1418-x

摘要: Four 2,5-dialkoxylphenyl-1,3,4-oxadiazoles are shown to be efficient organogelators. These compounds readily form stable gels in many organic solvents and their gelation property as well as supramolecular structures were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), H nuclear magnetic resonance ( H NMR), and ultraviolet-visible spectroscopy (UV-vis). The results indicate that the gelator molecules self-assemble into gels with elongated fibrous networks and layer structures, and van der Waals interaction is the main driving force.

关键词: 1     3     4-oxadiazoles     organogelator     self-assembly    

Fabrication, modification and environmental applications of TiO

S. ROHANI, T. ISIMJAN, A. MOHAMED, H. KAZEMIAN, M. SALEM, T. WANG

《化学科学与工程前沿(英文)》 2012年 第6卷 第1期   页码 112-122 doi: 10.1007/s11705-011-1144-6

摘要: Among the semiconductors, titanium dioxide has been identified as an effective photocatalyst due to its abundance, low cost, stability, and superior electronic energy band structure. Highly ordered nanotube arrays of titania were produced by anodization and mild sonication. The band gap energy of the titania nanotube arrays was reduced to 2.6 eV by co-doping with Fe, C, N atoms using an electrolyte solution containing K Fe(CN) . The photoconversion of phenol in a batch photoreactor increased to more than 18% based on the initial concentration of phenol by using a composite nanomaterial consisting of titania nanotube arrays and Pt/ZIF-8 nanoparticles. A layer-by-layer assembly technique for the deposition of titania nanoparticles was developed to fabricate air filters for the degradation of trace amounts of toluene in the air and preparation of superhyrophobic surfaces for oil-water separation and anti-corrosion surfaces.

关键词: TiO2 nanotube arrays and nanoparticles     anodization     bandgap modification     layer-by-layer deposition     oil-water separation    

Organogelators based on

Yan Zhai,Wei Chai,Wenwen Cao,Zipei Sun,Yaodong Huang

《化学科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 488-493 doi: 10.1007/s11705-015-1503-9

摘要: A series of -alkoxylbenzamides featuring a long alkyl chain have been synthesized and are readily to form stable gels in a variety of organic solvents. Their self-assembly properties and structure-property relationship were investigated by scanning electron microscopy, X-ray diffraction, H nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The gels formed were multi-responsive to environmental stimuli such as temperature and fluoride anion. The results show that a combination of hydrogen bonding, π-π stacking and van der Waals interaction result in the aggregation of -alkoxylbenzamides to form three-dimension networks, depending on the length of the long alkyl chain.

关键词: p-alkoxylbenzamide     organogelator     self-assembly     gelation    

Self-assembly of metal-cholesterol oxidase hybrid nanostructures and application in bioconversion of

Yu Xin, Qiuyue Gao, Yu Gu, Mengyao Hao, Guangming Fan, Liang Zhang

《化学科学与工程前沿(英文)》 2021年 第15卷 第3期   页码 615-629 doi: 10.1007/s11705-020-1989-7

摘要: A cholesterol oxidase (COD) was hybridized with Ca , Zn , Al , Fe and Mn . After precipitation with PO at 4 °C for 72 h, the resulting pellets were freeze-dried. In scanning electron microscopy assays, the metal-COD complexes revealed flower-like or granular structures after hybridization. Fourier transform infrared spectroscopy assay revealed the characteristic peaks of both the enzyme and metal materials. X-ray diffraction analysis indicated that COD was encapsulated in CaHPO ·2H O-, Zn (PO ) ·4H O-, AlPO -, FeP - and Mn (PO ) ·3H O-based nanostructures, respectively. Differential scanning calorimetry assay indicated significant increases in thermo-denaturation temperatures from 60.5 °C to 167.02 °C, 167.02 °C, 137.70 °C, 172.85 °C and 160.99 °C, respectively. Using steroid derivatives as substrates, this enzyme could convert cholesterol, pregnenolone, dehydroepiandrosterone, ergosterol, -sitosterol and stigmasterol to related single products. Hybridization in metal-based nanostructures could significantly enhance the initial conversion ratio and reaction stability of the enzyme. In addition, substrate selectivity could be affected by various metal materials. Briefly, using Ca , Zn , Al , Fe and Mn as hybrid raw materials could help to encapsulate COD in related metal-enzyme nanostructures, and could help to promote the stability and tolerant properties of the enzyme, while also enhancing its catalytic characteristics.

关键词: cholesterol oxidase     metal-enzyme hybridization     nanostructures     sterol derivatives     bioconversion    

Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placedrubber layer

《结构与土木工程前沿(英文)》   页码 1145-1162 doi: 10.1007/s11709-023-0945-2

摘要: To realize seismic-resilient reinforced concrete (RC) moment-resisting frame structures, a novel self-centering RC column with a rubber layer placed at the bottom (SRRC column) is proposed herein. For the column, the longitudinal reinforcement dissipates seismic energy, the rubber layer allows the rocking of the column, and the unbonded prestressed tendon enables self-centering capacity. A refined finite element model of the SRRC column is developed, the effectiveness of which is validated based on experimental results. Results show that the SRRC column exhibits stable energy dissipation capacity and no strength degradation; additionally, it can significantly reduce permanent residual deformation and mitigate damage to concrete. Extensive parametric studies pertaining to SRRC columns have been conducted to investigate the critical factors affecting their seismic performance.

关键词: seismic resilience     self-centering     rubber layer     flag-shaped hysteresis loop     parametric study    

Construction of a CaHPO4-PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

《化学科学与工程前沿(英文)》 2019年 第13卷 第3期   页码 554-562 doi: 10.1007/s11705-019-1834-z

摘要: Glycyrrhetinic acid 3- -mono- -D-glucuronide (GAMG), an important pharmaceutical intermediate and functional sweetener, has broad applications in the food and medical industries. A green and cost-effective method for its preparation is highly desired. Using site-directed mutagenesis, we previously obtained a variant of -glucuronidase from Li-3 (PGUS1), which can specifically transform glycyrrhizin (GL) into GAMG. In this study, a facile method was established to prepare a CaHPO -PGUS1 hybrid nanoflower for enzyme immobilization, based on protein-inorganic hybrid self-assembly. Under optimal conditions, 1.2 mg of a CaHPO -PGUS1 hybrid nanoflower precipitate with 71.2% immobilization efficiency, 35.60 mg∙g loading capacity, and 118% relative activity was obtained. Confocal laser scanning microscope and scanning electron microscope results showed that the enzyme was encapsulated in the CaHPO -PGUS1 hybrid nanoflower. Moreover, the thermostability of the CaHPO -PGUS1 hybrid nanoflower at 55°C was improved, and its half-life increased by 1.3 folds. Additionally, the CaHPO -PGUS1 hybrid nanoflower was used for the preparation of GAMG through GL hydrolysis, with the conversion rate of 92% in 8 h, and after eight consecutive runs, it had 60% of its original activity.

关键词: β-glucuronidase     enzyme-inorganic hybrid nanoflower     biotransformation     glycyrrhizin     glycyrrtinic acid 3-O-mono-β-D-glucuronide    

标题 作者 时间 类型 操作

Control on self-assembly structures of rod-coil-rod (PANI)-(PEG)-(PANI) triblock copolymer

YANG Zhifang, WU Jingao, YANG Yingkui, ZHOU Xingping, XIE Xiaolin

期刊论文

Ionic strength directed self-assembled polyelectrolyte single-bilayer membrane for low-pressure nanofiltration

期刊论文

Enzyme-instructed self-assembly of peptides containing phosphoserine to form supramolecular hydrogels

Jie Zhou, Xuewen Du, Jiaqing Wang, Natsuko Yamagata, Bing Xu

期刊论文

Supramolecular self-assembly of two-component systems comprising aromatic amides/Schiff base and tartaric

Xin Wang, Wei Cui, Bin Li, Xiaojie Zhang, Yongxin Zhang, Yaodong Huang

期刊论文

Shrink-induced graphene sensor for alpha-fetoprotein detection with low-cost self-assembly and label-free

Shota SANDO, Bo ZHANG, Tianhong CUI

期刊论文

Two-dimensional self-assembly of melem and melemium cations at pH-controlled aqueous solution–Au(111)

Shinobu Uemura,Kenki Sakata,Masashi Aono,Yusuke Nakamura,Masashi Kunitake

期刊论文

Effects of solvents and temperature on spherulites of self-assembled phloroglucinol tristearate

Yawen Yao, Sabine Rosenfeldt, Kai Zhang

期刊论文

The construction of pseudo-Janus silica/surfactant assembly and their application to stabilize Pickering

期刊论文

Fabrication and mechanical properties of single-wall carbon nanotubes and hyperbranched diazonium salt multilayers

LI Xinyang, FAN Pengwei, TUO Xinlin, WANG Xiaogong

期刊论文

2,5-Dialkoxylphenyl-1,3,4-oxadiazoles as efficient organogelators and their self-assembling property

Zipei SUN,Xuelin DONG,Yan ZHAI,Ziyan Li,Yaodong HUANG

期刊论文

Fabrication, modification and environmental applications of TiO

S. ROHANI, T. ISIMJAN, A. MOHAMED, H. KAZEMIAN, M. SALEM, T. WANG

期刊论文

Organogelators based on

Yan Zhai,Wei Chai,Wenwen Cao,Zipei Sun,Yaodong Huang

期刊论文

Self-assembly of metal-cholesterol oxidase hybrid nanostructures and application in bioconversion of

Yu Xin, Qiuyue Gao, Yu Gu, Mengyao Hao, Guangming Fan, Liang Zhang

期刊论文

Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placedrubber layer

期刊论文

Construction of a CaHPO4-PGUS1 hybrid nanoflower through protein-inorganic self-assembly, and its application

Tian Jiang, Yuhui Hou, Tengjiang Zhang, Xudong Feng, Chun Li

期刊论文