Natural wax gelators have different compositions of compounds(hydrocarbons,wax esters,free fatty alcohols,and free fatty acids),which results in oleogels with varying properties.To maintain a consistent composition,th...Natural wax gelators have different compositions of compounds(hydrocarbons,wax esters,free fatty alcohols,and free fatty acids),which results in oleogels with varying properties.To maintain a consistent composition,the individual components can be added to the original wax gelator.The content of hydrocarbons and wax esters greatly affects the structuring process of liquid edible oils with waxes.The aim of this study was to evaluate the possibility of modifying the properties of beeswax as a gelling agent by adding hydrocarbons or monoesters to obtain oleogels with specific properties.Various tests were conducted to assess the changes in the oleogel properties,such as color,microstructure,oil-binding capacity,thermal and textural properties.The research results have shown that the addition of the studied fractions has led to a significant change in all properties of oleogels.The initial size of oleogel crystals(7.29±1.80μm)changed after adding fractions,varying from 5.28μm to 12.58μm with hydrocarbons and from 9.95μm to 30.41μm with wax esters.The addition of 30%–50% hydrocarbons decreased the ability of the oleogels to bind oil and made them less firm compared to samples with 10%-20% hydrocarbons.Adding 10%-20% monoesters increased the firmness of the oleogels,but this indicator decreased when their content was increased to 50%.The obtained data indicate that hydrocarbons and wax esters can be used for targeted correction of the gelling properties of beeswax.展开更多
Supercooling of the microencapsulated phase change materials（PCMs） during cooling usually happens. This phenomenon can interfere with heat transfer and is necessary to further overcome. In this study, mela- mine-for...Supercooling of the microencapsulated phase change materials（PCMs） during cooling usually happens. This phenomenon can interfere with heat transfer and is necessary to further overcome. In this study, mela- mine-formaldehyde microcapsules containing two n-alkane PCMs, namely, n-dodecane（Cl2） or n-tetradecane（C14） were prepared by in situ polymerization. A small amount of n-hexatriacontane（C36） was introduced as an organic ge- lator into the core of microcapsules to cope with the supercooling problem. Analyses demonstrate that supercooling of the microencapsulated C12 or C14 was significantly suppressed by adding 3%（mass fraction） C36, without changing the spherical morphology and dispersibility. It could be also found that the enthalpy of microencapsulated CI2 or C14 containing C36 was similar to that of microencapsulated n-alkanes without C36, whereas the difference between onsets of crystallization and melting（degree of supercooling） is similar to that of those of pure n-alkanes, suggesting the re- markable suppression ability of the organic gelator on supercooling.展开更多
A liquid crystalline gelator containing the azobenzene chromophore was synthesized for the first time; it was used to form self- assembled network in nematic liquid crystals resulting in liquid crystal gels with disti...A liquid crystalline gelator containing the azobenzene chromophore was synthesized for the first time; it was used to form self- assembled network in nematic liquid crystals resulting in liquid crystal gels with distinct features.展开更多
In order to define the chemical conformation of gelator,para-hydroxy pyridinium salt of 1,2,4,5-benzene tetracarboxylic acid（defined as G1）,four model compounds were prepared from para-,meta-,ortho-phthalic acid wit...In order to define the chemical conformation of gelator,para-hydroxy pyridinium salt of 1,2,4,5-benzene tetracarboxylic acid（defined as G1）,four model compounds were prepared from para-,meta-,ortho-phthalic acid with 4-hydroxy pyridine（PHP）,and 1,2,4,5-benzene tetracarboxylic acid（BTA） with 4-pyridylcarbinol（PCB）,and their 1H NMR spectra were investigated.The single crystal of G1 obtained directly from gelling solvent was measured,which displayed complicated hydrogen-bonded networks arising from the supramolecular synthons and other weak interactions between H20 and the components. The powder X-ray diffraction （XRPD） experiments were also carded out to understand the relationship between molecular packing of the bulk crystal and the gelation behavior.展开更多
1,3:2,4-di-p-methylbenzylidene-D-sorbitol(MDBS)is known to be an efficient sorbitol derivative gelator.Two new sorbitol derivative gelators were designed and synthesized in contrast to MDBS in order to study the gel p...1,3:2,4-di-p-methylbenzylidene-D-sorbitol(MDBS)is known to be an efficient sorbitol derivative gelator.Two new sorbitol derivative gelators were designed and synthesized in contrast to MDBS in order to study the gel properties of gelators with different structures.Their gelation behavior to 30 solvents was investigated.It was found that the gelation behavior was related to the molecular structure of gelators.Compared with MDBS,the gelator with more hydroxyl in the molecular structure could gel water and that with more aromatic ring could gel aromatic solvent.The fibrous and three-dimensional network of the gels was obtained by scanning electron microscopy(SEM).Ultraviolet-visible(UV-Vis)spectroscopy revealed thatπ-πinteraction was one of the main driving forces for the formation of gels.Theπ-πstacking of gelation increases with the number of aromatic rings in the molecular structure of gelator.Fourier transform infrared(FT-IR)spectroscopy revealed that the hydrogen bonding was also the main driving force for the formation of gels.The layered structure of the gels was studied by X-ray diffraction(XRD).展开更多
A supramolecular hydrogel （defined as G1） formed from 1,2,4,5-benzene tetracarboxylic acid （BTCA） and 2-amino-3- hydroxypyridine possessed higher Tgel than that of another hydrogel （defined as G2） formed from BT...A supramolecular hydrogel （defined as G1） formed from 1,2,4,5-benzene tetracarboxylic acid （BTCA） and 2-amino-3- hydroxypyridine possessed higher Tgel than that of another hydrogel （defined as G2） formed from BTCA and 3-hydroxypyridine. Based on the analysis of their xerogels by 1H NMR, IR and XRD, the higher stability of G1 was attributed to the formation of stronger hydrogen binding enhanced by the ortho amino group of 2-amino-3-hydroxypyridine.展开更多
Tetrathiafulvalene (TTF) and its derivatives have been intensively investigated for conducting materials for more than 30 years.As π-electron donors,TTF and its derivatives can be reversibly transformed into the resp...Tetrathiafulvalene (TTF) and its derivatives have been intensively investigated for conducting materials for more than 30 years.As π-electron donors,TTF and its derivatives can be reversibly transformed into the respective TTF.+ and TTF2+.Due to its reversible feature,the TTF unit has been widely employed as the building block for switchable systems.In recent years studies of conducting nanostructures of TTF derivatives have received more and more attention.One simple way to prepare nano-structures is through the gelation processes.In this review,we have discussed recent progress in stimuli-responsive gels and conducting nanostructures based on TTF-based gelators.展开更多
A series of p-alkoxylbenzamides featuring a long alkyl chain have been synthesized and are readily to form stable gels in a variety of organic solvents. Their selfassembly properties and structure-property relationshi...A series of p-alkoxylbenzamides featuring a long alkyl chain have been synthesized and are readily to form stable gels in a variety of organic solvents. Their selfassembly properties and structure-property relationship were investigated by scanning electron microscopy, X-ray diffraction, IH 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, n-n stacking and van der Waals interaction result in the aggregation of palkoxylbenzamides to form three-dimension networks, depending on the length of the long alkyl chain.展开更多
A novel gelator that contained both Schiffbase and L-lysine moieties was synthesized and its gelation behavior was tested. This gelator can form gels in various organic solvents. The resulting gel can be applied as a ...A novel gelator that contained both Schiffbase and L-lysine moieties was synthesized and its gelation behavior was tested. This gelator can form gels in various organic solvents. The resulting gel can be applied as a fascinating platform for visual recognition of enantiomeric 1 -（2-hydroxynaphthalen- 1-yl）naphthalen-2-ol （B1NOL） through selective gel collapse. In addition, the mechanism for the reaction of the gel with chiral BINOL was investigated by scanning electron microscope and 1H nuclear magnetic resonance.展开更多
An amphiphilic tetrathiafulvalene molecule was designed and readily synthesized. The am-TTF can gelate a variety of organic solvents in view of multiple intermolecular interactions, especially in polar solvent.SEM obs...An amphiphilic tetrathiafulvalene molecule was designed and readily synthesized. The am-TTF can gelate a variety of organic solvents in view of multiple intermolecular interactions, especially in polar solvent.SEM observation provided clear evidence for the self-assembled micro/nanofibers morphologies in gelation state. Moreover, XRD measurements indicated the formation of highly-ordered columnar structures. The FT-IR spectra revealed that the formation of mixed-valence states with the absorption over 1700 cm^(-1), showing the semiconductive behaviors with the conductivity of 10^(-4)S/cm. The am-TTF based conducting fibers could be promising candidates for organic electronics.展开更多
Hydrogels formed by gelators have attracted growing attention for their promising application in biomaterials and biotechnology, We describe in this paper the generation and characterization of a novel photo-, thermal...Hydrogels formed by gelators have attracted growing attention for their promising application in biomaterials and biotechnology, We describe in this paper the generation and characterization of a novel photo-, thermal- and pH-responsive hydrogel based on an amino acid gelator AA-Azo-EG6. Specifically, the gelator bears an amino acid head, an azobenzene （Azo） linker, and a short oligoethylene glycol tail （EG6）. The resulting AA-Azo-EG6 hydrogel is injectable and exhibits interesting helical self-assembled structures, Meanwhile, the hydrogel is able to experience a gel-sol or gel-precipitate phase transition responding to external stimuli. Thus, this AA-Azo-EG6 gelator is a promising building block for intelligent materials and drug delivery.展开更多
This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room ...This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room temperature,gel emulsions and gel film formation,etc.Potential applications of the LMMGs in spilled oil collection and water purification are briefly presented.展开更多
Due to the mutual repulsion between their hydrophilic surface terminations and the high surface energy facilitating their ran-dom restacking,2D MXene nanosheets usually cannot self-assemble into 3D macroscopic gels wi...Due to the mutual repulsion between their hydrophilic surface terminations and the high surface energy facilitating their ran-dom restacking,2D MXene nanosheets usually cannot self-assemble into 3D macroscopic gels with various applications in the absence of proper linking agents.In this work,a rapid spontaneous gelation of Ti3C2Tx MXene with a very low dispersion concentration of 0.5 mg mL^(-1) into multifunctional architectures under moderate centrifugation is illustrated.The as-prepared MXene gels exhibit reconfigurable internal structures and tunable rheological,tribological,electrochemical,infrared-emissive and photothermal-conversion properties based on the pH-induced changes in the surface chemistry of Ti_(3)C_(2)T_(x) nanosheets.By adopting a gel with optimized pH value,high lubrication,exceptional specific capacitances(~635 and~408 F g^(-1) at 5 and 100 mV s^(-1),respectively),long-term capacitance retention(~96.7%after 10,000 cycles)and high-precision screen-or extrusion-printing into different high-resolution anticounterfeiting patterns can be achieved,thus displaying extensive potential applications in the fields of semi-solid lubrication,control-lable devices,supercapacitors,information encryption and infrared camouflaging.展开更多
The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fab...The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fabricated through filtration-induced delaminated gelation and ambient drying.The delaminated gelation process involves the assembly of fluorinated cellulose nanofiber(FCNF)at the solid-liquid interface between the filter and the filtrate during filtration,resulting in the formation of lamellar FCNF hydrogels with strong intra-plane and weak interlayer hydrogen bonding.By exchanging the solvents from water to hexane,the hydrogen bonding in the FCNF hydrogel is further enhanced,enabling the formation of the DAF with intra-layer mesopores upon ambient drying.The resulting aerogel film is lightweight and ultra-flexible,which pos-sesses desirable properties of high visible-light transmittance(91.0%),low thermal conductivity(33 mW m^(-1) K^(-1)),and high atmospheric-window emissivity(90.1%).Furthermore,the DAF exhibits reduced surface energy and exceptional hydrophobicity due to the presence of fluorine-containing groups,enhancing its durability and UV resistance.Consequently,the DAF has demonstrated its potential as solar-thermal regulatory cooling window materials capable of simultaneously providing indoor lighting,thermal insulation,and daytime radiative cooling under direct sunlight.Significantly,the enclosed space protected by the DAF exhibits a temperature reduction of 2.6℃ compared to that shielded by conventional architectural glass.展开更多
We developed a new preparation to protect probiotic cells from adverse environmental conditions and improve their livability,which is called Lactobacillus casei-Sodium alginate-Chitosan (LSC).The LSC was prepared by m...We developed a new preparation to protect probiotic cells from adverse environmental conditions and improve their livability,which is called Lactobacillus casei-Sodium alginate-Chitosan (LSC).The LSC was prepared by mixing probiotics with sodium alginate-chitosan sol.The preparation contained complex calcium ions,which were released in the acidic environment of gastric juice,thus crosslinking to form in-situ gel.Different proportions of sodium alginate-chitosan were prepared to add to simulate gastrointestinal fluid to get the best ratio.The optimal ratio of LSC preparation was compared with traditional gel microspheres to observe the survival effect of probiotics in gastrointestinal fluid environment.Compared with sodium alginate sol,the porosity of sodium alginate-chitosan sol is lower,which is beneficial to the protection of probiotics.When the ratio of chitosan to sodium alginate is 1.5:1.5 (w/v),the protective effect is the best.The protective ability of LSC is 64 times that of traditional microspheres,and it has the potential of synergistic anti-tumor.A probiotic preparation with simple preparation process and better protection effect compared with traditional microspheres was prepared,which has joint anti-tumor potential.展开更多
In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel ...In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel gelation time are complicated or have low responsiveness.There is an urgent need for an effective method for delaying gel gelation time with intelligent response.Inspired by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO_(2) in aqueous solution as a capsule to prepare an intelligent responsive self-assembled micro-nanocapsules.The capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation time.When the pH value is 2 and the concentration of gas-phase hydrophobic SiO_(2) particles is 10%,the gelation time of the capsule gel system at 30,60,90,and 120℃is12.5,13.2,15.2,and 21.1 times longer than that of the gel system without containing capsule,respectively.Compared with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 322 Pa.The intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel strength.The slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.展开更多
[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the flo...[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the floating balls. [Methods] The effects of the types and amounts of isocyanate, chain extenders and polyether polyols on the gelation rate, adhesion and wear resistance of polyurea elastomer were investigated, and it was finally determined the preparation process of polyurea elastomer using liquid isophorone diisocyanate (IPDI) and amino-terminated polyether (D2000) as the main raw materials, dimethylthiotoluene diamine (E300) as the chain extender and silica as the wear resistance modifier through two-step solution polymerization of prepolymerization and chain extension. [Results] The physical properties and chemical resistance tests of spray polyurea elastomer showed that it had good physical properties and acid and alkali resistance, and could meet the requirements of spraying and protection of EPS floating ball surface in marine environment. [Conclusions] Polyurea elastomer coating can improve the aging resistance, wear resistance and acid and alkali resistance of EPS floating balls, and prevent them from being fragile and floating randomly to form marine floating garbage which results in "white pollution".展开更多
New supramolecular hydrogels with the maximal sol-gel transition temperature （Tgel） of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid （BTA） and para-hydroxyl pyridine （PHP） or ...New supramolecular hydrogels with the maximal sol-gel transition temperature （Tgel） of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid （BTA） and para-hydroxyl pyridine （PHP） or meta-hydroxyl pyridine （MHP）. The single crystal structure of the complex formed from BTA and ortho-hydroxyl pyridine （OHP） indicated that the molecules assembled into superstructure via both hydrogen bonds and π--π stacking interaction.展开更多
N-Octadecyl-N1-maleoyl-L-phenylalanine （ODMA-L-Phe） was synthesized through the condensation, deprotection and acid- ylation reaction of BOC-L-phenylalanine, octadecylamine and maleic anhydride. ODMA-L-Phe can self-...N-Octadecyl-N1-maleoyl-L-phenylalanine （ODMA-L-Phe） was synthesized through the condensation, deprotection and acid- ylation reaction of BOC-L-phenylalanine, octadecylamine and maleic anhydride. ODMA-L-Phe can self-assemble in some organic solvents and turned them into thermally reversible physical supramolecular organogels. The morphology of ODMA-L-Phe aggregates was characterized by polarized optical microscopy （POM） and field emission scanning electron microscope （FE-SEM）. The aggregates of ODMA-L-Phe were needle-like fibrils with diameters of approximately 100-200 nm. The mechanism of ODMA- L-Phe self-assembly in organic solvents was investigated using XH NMR and circular dichroism （CD）. The results indicated that hydrogen bonding was one of the main driving forces for the self-assembly of ODMA-L-Phe.展开更多
基金supported by the Russian Science Foundation under grant(Project No.19-16-00113).
文摘Natural wax gelators have different compositions of compounds(hydrocarbons,wax esters,free fatty alcohols,and free fatty acids),which results in oleogels with varying properties.To maintain a consistent composition,the individual components can be added to the original wax gelator.The content of hydrocarbons and wax esters greatly affects the structuring process of liquid edible oils with waxes.The aim of this study was to evaluate the possibility of modifying the properties of beeswax as a gelling agent by adding hydrocarbons or monoesters to obtain oleogels with specific properties.Various tests were conducted to assess the changes in the oleogel properties,such as color,microstructure,oil-binding capacity,thermal and textural properties.The research results have shown that the addition of the studied fractions has led to a significant change in all properties of oleogels.The initial size of oleogel crystals(7.29±1.80μm)changed after adding fractions,varying from 5.28μm to 12.58μm with hydrocarbons and from 9.95μm to 30.41μm with wax esters.The addition of 30%–50% hydrocarbons decreased the ability of the oleogels to bind oil and made them less firm compared to samples with 10%-20% hydrocarbons.Adding 10%-20% monoesters increased the firmness of the oleogels,but this indicator decreased when their content was increased to 50%.The obtained data indicate that hydrocarbons and wax esters can be used for targeted correction of the gelling properties of beeswax.
文摘Supercooling of the microencapsulated phase change materials（PCMs） during cooling usually happens. This phenomenon can interfere with heat transfer and is necessary to further overcome. In this study, mela- mine-formaldehyde microcapsules containing two n-alkane PCMs, namely, n-dodecane（Cl2） or n-tetradecane（C14） were prepared by in situ polymerization. A small amount of n-hexatriacontane（C36） was introduced as an organic ge- lator into the core of microcapsules to cope with the supercooling problem. Analyses demonstrate that supercooling of the microencapsulated C12 or C14 was significantly suppressed by adding 3%（mass fraction） C36, without changing the spherical morphology and dispersibility. It could be also found that the enthalpy of microencapsulated CI2 or C14 containing C36 was similar to that of microencapsulated n-alkanes without C36, whereas the difference between onsets of crystallization and melting（degree of supercooling） is similar to that of those of pure n-alkanes, suggesting the re- markable suppression ability of the organic gelator on supercooling.
文摘A liquid crystalline gelator containing the azobenzene chromophore was synthesized for the first time; it was used to form self- assembled network in nematic liquid crystals resulting in liquid crystal gels with distinct features.
文摘In order to define the chemical conformation of gelator,para-hydroxy pyridinium salt of 1,2,4,5-benzene tetracarboxylic acid（defined as G1）,four model compounds were prepared from para-,meta-,ortho-phthalic acid with 4-hydroxy pyridine（PHP）,and 1,2,4,5-benzene tetracarboxylic acid（BTA） with 4-pyridylcarbinol（PCB）,and their 1H NMR spectra were investigated.The single crystal of G1 obtained directly from gelling solvent was measured,which displayed complicated hydrogen-bonded networks arising from the supramolecular synthons and other weak interactions between H20 and the components. The powder X-ray diffraction （XRPD） experiments were also carded out to understand the relationship between molecular packing of the bulk crystal and the gelation behavior.
基金Supported by National Natural Science Foundation of China(No.21276188)
文摘1,3:2,4-di-p-methylbenzylidene-D-sorbitol(MDBS)is known to be an efficient sorbitol derivative gelator.Two new sorbitol derivative gelators were designed and synthesized in contrast to MDBS in order to study the gel properties of gelators with different structures.Their gelation behavior to 30 solvents was investigated.It was found that the gelation behavior was related to the molecular structure of gelators.Compared with MDBS,the gelator with more hydroxyl in the molecular structure could gel water and that with more aromatic ring could gel aromatic solvent.The fibrous and three-dimensional network of the gels was obtained by scanning electron microscopy(SEM).Ultraviolet-visible(UV-Vis)spectroscopy revealed thatπ-πinteraction was one of the main driving forces for the formation of gels.Theπ-πstacking of gelation increases with the number of aromatic rings in the molecular structure of gelator.Fourier transform infrared(FT-IR)spectroscopy revealed that the hydrogen bonding was also the main driving force for the formation of gels.The layered structure of the gels was studied by X-ray diffraction(XRD).
文摘A supramolecular hydrogel （defined as G1） formed from 1,2,4,5-benzene tetracarboxylic acid （BTCA） and 2-amino-3- hydroxypyridine possessed higher Tgel than that of another hydrogel （defined as G2） formed from BTCA and 3-hydroxypyridine. Based on the analysis of their xerogels by 1H NMR, IR and XRD, the higher stability of G1 was attributed to the formation of stronger hydrogen binding enhanced by the ortho amino group of 2-amino-3-hydroxypyridine.
基金supported by the National Natural Science Foundation of China,the State Basic Program and Chinese Academy of Sciencessupported by the NSFC-DFG joint project (TRR61)
文摘Tetrathiafulvalene (TTF) and its derivatives have been intensively investigated for conducting materials for more than 30 years.As π-electron donors,TTF and its derivatives can be reversibly transformed into the respective TTF.+ and TTF2+.Due to its reversible feature,the TTF unit has been widely employed as the building block for switchable systems.In recent years studies of conducting nanostructures of TTF derivatives have received more and more attention.One simple way to prepare nano-structures is through the gelation processes.In this review,we have discussed recent progress in stimuli-responsive gels and conducting nanostructures based on TTF-based gelators.
文摘A series of p-alkoxylbenzamides featuring a long alkyl chain have been synthesized and are readily to form stable gels in a variety of organic solvents. Their selfassembly properties and structure-property relationship were investigated by scanning electron microscopy, X-ray diffraction, IH 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, n-n stacking and van der Waals interaction result in the aggregation of palkoxylbenzamides to form three-dimension networks, depending on the length of the long alkyl chain.
基金We greatly appreciate the support of the National Natural Science Foundation of China （Grant Nos. 21272054 and 21502040）, Natural Science Foundation of Hebei Province （B2016205249 and B2016205211）, Youth Top-notch Talent Foundation of the Education Department of Hebei Province （No. BJ2014039）, Science and Technology Research Fund of the Education Department of Hebei Province （No. ZD2015030） and the Startup Foundation of Hebei Normal University （Nos. L2015B08, L2015B09, L2015k02 and L2016Z01）
文摘A novel gelator that contained both Schiffbase and L-lysine moieties was synthesized and its gelation behavior was tested. This gelator can form gels in various organic solvents. The resulting gel can be applied as a fascinating platform for visual recognition of enantiomeric 1 -（2-hydroxynaphthalen- 1-yl）naphthalen-2-ol （B1NOL） through selective gel collapse. In addition, the mechanism for the reaction of the gel with chiral BINOL was investigated by scanning electron microscope and 1H nuclear magnetic resonance.
基金supported by the National Natural Science Foundation of China (No. 61106068)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education MinistryJilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis (No. 130028831)
文摘An amphiphilic tetrathiafulvalene molecule was designed and readily synthesized. The am-TTF can gelate a variety of organic solvents in view of multiple intermolecular interactions, especially in polar solvent.SEM observation provided clear evidence for the self-assembled micro/nanofibers morphologies in gelation state. Moreover, XRD measurements indicated the formation of highly-ordered columnar structures. The FT-IR spectra revealed that the formation of mixed-valence states with the absorption over 1700 cm^(-1), showing the semiconductive behaviors with the conductivity of 10^(-4)S/cm. The am-TTF based conducting fibers could be promising candidates for organic electronics.
基金supported by [18_TD$IF]State High-Tech Development Program of China (863 Program, No. 2015AA020941)the National Natural Science Foundation of China(Nos. NSFC21474004 and NSFC21434008)the Youth Thousand-Talents Program of China for support
文摘Hydrogels formed by gelators have attracted growing attention for their promising application in biomaterials and biotechnology, We describe in this paper the generation and characterization of a novel photo-, thermal- and pH-responsive hydrogel based on an amino acid gelator AA-Azo-EG6. Specifically, the gelator bears an amino acid head, an azobenzene （Azo） linker, and a short oligoethylene glycol tail （EG6）. The resulting AA-Azo-EG6 hydrogel is injectable and exhibits interesting helical self-assembled structures, Meanwhile, the hydrogel is able to experience a gel-sol or gel-precipitate phase transition responding to external stimuli. Thus, this AA-Azo-EG6 gelator is a promising building block for intelligent materials and drug delivery.
基金supported by the National High-Tech Research & Devel-opment Program of China (863 Project) (2007AA03Z349)the National Natural Science Foundation of China (20902055,20927001,91027017)the 13115 Project of Shaanxi Province (2010ZDKG-89)
文摘This article is intended to provide an overview of recent progress in the studies of cholesterol-based low-molecular mass gelators (LMMGs) with unusual properties,in particular,gelation and selective gelation at room temperature,gel emulsions and gel film formation,etc.Potential applications of the LMMGs in spilled oil collection and water purification are briefly presented.
基金This work is financially supported by the Hundred Talents Program of Chinese Academy of Sciences(E30247YB)the Special Talents Program of Lanzhou Institute of Chemical Physics(E0SX0282)+1 种基金the National Natural Science Foundation of Shandong Province(ZR2022QB190)the Innovative Research Funds of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai(E1R06SXM07,E1R06SXM09 and E2R06SXM14).
文摘Due to the mutual repulsion between their hydrophilic surface terminations and the high surface energy facilitating their ran-dom restacking,2D MXene nanosheets usually cannot self-assemble into 3D macroscopic gels with various applications in the absence of proper linking agents.In this work,a rapid spontaneous gelation of Ti3C2Tx MXene with a very low dispersion concentration of 0.5 mg mL^(-1) into multifunctional architectures under moderate centrifugation is illustrated.The as-prepared MXene gels exhibit reconfigurable internal structures and tunable rheological,tribological,electrochemical,infrared-emissive and photothermal-conversion properties based on the pH-induced changes in the surface chemistry of Ti_(3)C_(2)T_(x) nanosheets.By adopting a gel with optimized pH value,high lubrication,exceptional specific capacitances(~635 and~408 F g^(-1) at 5 and 100 mV s^(-1),respectively),long-term capacitance retention(~96.7%after 10,000 cycles)and high-precision screen-or extrusion-printing into different high-resolution anticounterfeiting patterns can be achieved,thus displaying extensive potential applications in the fields of semi-solid lubrication,control-lable devices,supercapacitors,information encryption and infrared camouflaging.
基金The authors are grateful for the financial support from the National Natural Science Foundation of China(Grant Nos.52273067,52122303,52233006)the Fundamental Research Funds for the Central Universities(Grant No.2232023A-03)the Shuguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(23SG29).
文摘The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fabricated through filtration-induced delaminated gelation and ambient drying.The delaminated gelation process involves the assembly of fluorinated cellulose nanofiber(FCNF)at the solid-liquid interface between the filter and the filtrate during filtration,resulting in the formation of lamellar FCNF hydrogels with strong intra-plane and weak interlayer hydrogen bonding.By exchanging the solvents from water to hexane,the hydrogen bonding in the FCNF hydrogel is further enhanced,enabling the formation of the DAF with intra-layer mesopores upon ambient drying.The resulting aerogel film is lightweight and ultra-flexible,which pos-sesses desirable properties of high visible-light transmittance(91.0%),low thermal conductivity(33 mW m^(-1) K^(-1)),and high atmospheric-window emissivity(90.1%).Furthermore,the DAF exhibits reduced surface energy and exceptional hydrophobicity due to the presence of fluorine-containing groups,enhancing its durability and UV resistance.Consequently,the DAF has demonstrated its potential as solar-thermal regulatory cooling window materials capable of simultaneously providing indoor lighting,thermal insulation,and daytime radiative cooling under direct sunlight.Significantly,the enclosed space protected by the DAF exhibits a temperature reduction of 2.6℃ compared to that shielded by conventional architectural glass.
基金Funded by the National Natural Science Foundation of China(No.52003211)。
文摘We developed a new preparation to protect probiotic cells from adverse environmental conditions and improve their livability,which is called Lactobacillus casei-Sodium alginate-Chitosan (LSC).The LSC was prepared by mixing probiotics with sodium alginate-chitosan sol.The preparation contained complex calcium ions,which were released in the acidic environment of gastric juice,thus crosslinking to form in-situ gel.Different proportions of sodium alginate-chitosan were prepared to add to simulate gastrointestinal fluid to get the best ratio.The optimal ratio of LSC preparation was compared with traditional gel microspheres to observe the survival effect of probiotics in gastrointestinal fluid environment.Compared with sodium alginate sol,the porosity of sodium alginate-chitosan sol is lower,which is beneficial to the protection of probiotics.When the ratio of chitosan to sodium alginate is 1.5:1.5 (w/v),the protective effect is the best.The protective ability of LSC is 64 times that of traditional microspheres,and it has the potential of synergistic anti-tumor.A probiotic preparation with simple preparation process and better protection effect compared with traditional microspheres was prepared,which has joint anti-tumor potential.
基金support and funding from the National Natural Science Foundation of China (No.52174047)Sinopec Project (No.P21063-3)。
文摘In the application of polymer gels to profile control and water shutoff,the gelation time will directly determine whether the gel can"go further"in the formation,but the most of the methods for delaying gel gelation time are complicated or have low responsiveness.There is an urgent need for an effective method for delaying gel gelation time with intelligent response.Inspired by the slow-release effect of drug capsules,this paper uses the self-assembly effect of gas-phase hydrophobic SiO_(2) in aqueous solution as a capsule to prepare an intelligent responsive self-assembled micro-nanocapsules.The capsule slowly releases the cross-linking agent under the stimulation of external conditions such as temperature and pH value,thus delaying gel gelation time.When the pH value is 2 and the concentration of gas-phase hydrophobic SiO_(2) particles is 10%,the gelation time of the capsule gel system at 30,60,90,and 120℃is12.5,13.2,15.2,and 21.1 times longer than that of the gel system without containing capsule,respectively.Compared with other methods,the yield stress of the gel without containing capsules was 78 Pa,and the yield stress after the addition of capsules was 322 Pa.The intelligent responsive self-assembled micronanocapsules prepared by gas-phase hydrophobic silica nanoparticles can not only delay the gel gelation time,but also increase the gel strength.The slow release of cross-linking agent from capsule provides an effective method for prolongating the gelation time of polymer gels.
基金Supported by Special Project for High-quality Development of Marine Services and Fishery in Fujian Province in 2023(FJHY-YYKJ-2023-1-3)。
文摘[Objectives] This study was conducted to develop a polyurea elastomer which can be sprayed on the surface of expanded polystyrene (EPS) floating balls, so as to improve the surface strength and service life of the floating balls. [Methods] The effects of the types and amounts of isocyanate, chain extenders and polyether polyols on the gelation rate, adhesion and wear resistance of polyurea elastomer were investigated, and it was finally determined the preparation process of polyurea elastomer using liquid isophorone diisocyanate (IPDI) and amino-terminated polyether (D2000) as the main raw materials, dimethylthiotoluene diamine (E300) as the chain extender and silica as the wear resistance modifier through two-step solution polymerization of prepolymerization and chain extension. [Results] The physical properties and chemical resistance tests of spray polyurea elastomer showed that it had good physical properties and acid and alkali resistance, and could meet the requirements of spraying and protection of EPS floating ball surface in marine environment. [Conclusions] Polyurea elastomer coating can improve the aging resistance, wear resistance and acid and alkali resistance of EPS floating balls, and prevent them from being fragile and floating randomly to form marine floating garbage which results in "white pollution".
基金support from the National Natural Science Foundation of China(Nos.20574041,20874055)
文摘New supramolecular hydrogels with the maximal sol-gel transition temperature （Tgel） of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid （BTA） and para-hydroxyl pyridine （PHP） or meta-hydroxyl pyridine （MHP）. The single crystal structure of the complex formed from BTA and ortho-hydroxyl pyridine （OHP） indicated that the molecules assembled into superstructure via both hydrogen bonds and π--π stacking interaction.
基金the National Natural Science Foundation of China(No.20474022)for financial support.
文摘N-Octadecyl-N1-maleoyl-L-phenylalanine （ODMA-L-Phe） was synthesized through the condensation, deprotection and acid- ylation reaction of BOC-L-phenylalanine, octadecylamine and maleic anhydride. ODMA-L-Phe can self-assemble in some organic solvents and turned them into thermally reversible physical supramolecular organogels. The morphology of ODMA-L-Phe aggregates was characterized by polarized optical microscopy （POM） and field emission scanning electron microscope （FE-SEM）. The aggregates of ODMA-L-Phe were needle-like fibrils with diameters of approximately 100-200 nm. The mechanism of ODMA- L-Phe self-assembly in organic solvents was investigated using XH NMR and circular dichroism （CD）. The results indicated that hydrogen bonding was one of the main driving forces for the self-assembly of ODMA-L-Phe.
