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-situ gelation of aqueous sulfomethylated resorcinol formaldehyde (SMRF) system inBerea core has been investigated. Two sets of displacement experiments were conducted with thissystem (containing 5% NaCl, 0. 036% Ca...In-situ gelation of aqueous sulfomethylated resorcinol formaldehyde (SMRF) system inBerea core has been investigated. Two sets of displacement experiments were conducted with thissystem (containing 5% NaCl, 0. 036% CaCl_2. 2H_2O). The brine permeabilities of the coreswere reduced significantly from about 600 to 0.1 md. The in-situ gelation in Berea core occurreda little bit earlier than gelation anticipated from bulk test in the experiments. The gel time waseasier to control at initial pH between 6 and 8. During injection of SMRF system, the apparentviscosity was less than 1 mPa·s at 41℃.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
The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extract...The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic oxides.This oxygen and metal extraction can be achieved using existing metallurgical techniques.Furthermore,the ample reserves of water ice on the Moon offer another means for oxygen production.This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental conditions.It delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar regolith.The two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the Moon.Considering the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon.This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.展开更多
Accurate acquisition and prediction of acoustic parameters of seabed sediments are crucial in marine sound propagation research.While the relationship between sound velocity and physical properties of sediment has bee...Accurate acquisition and prediction of acoustic parameters of seabed sediments are crucial in marine sound propagation research.While the relationship between sound velocity and physical properties of sediment has been extensively studied,there is still no consensus on the correlation between acoustic attenuation coefficient and sediment physical properties.Predicting the acoustic attenuation coefficient remains a challenging issue in sedimentary acoustic research.In this study,we propose a prediction method for the acoustic attenuation coefficient using machine learning algorithms,specifically the random forest(RF),support vector machine(SVR),and convolutional neural network(CNN)algorithms.We utilized the acoustic attenuation coefficient and sediment particle size data from 52 stations as training parameters,with the particle size parameters as the input feature matrix,and measured acoustic attenuation as the training label to validate the attenuation prediction model.Our results indicate that the error of the attenuation prediction model is small.Among the three models,the RF model exhibited the lowest prediction error,with a mean squared error of 0.8232,mean absolute error of 0.6613,and root mean squared error of 0.9073.Additionally,when we applied the models to predict the data collected at different times in the same region,we found that the models developed in this study also demonstrated a certain level of reliability in real prediction scenarios.Our approach demonstrates that constructing a sediment acoustic characteristics model based on machine learning is feasible to a certain extent and offers a novel perspective for studying sediment acoustic properties.展开更多
All-safe liquid-state lithium-ion batteries(ASLS-LIBs) is of great interest as they can potentially combine the safety of all-solid-state batteries with the high performance and low manufacturing cost of traditional l...All-safe liquid-state lithium-ion batteries(ASLS-LIBs) is of great interest as they can potentially combine the safety of all-solid-state batteries with the high performance and low manufacturing cost of traditional liquid-state LIBs. However, the practical success of ASLS-LIBs is bottlenecked by the lack of advanced separator technology that can simultaneously realize high performances in puncturing-tolerability,fire-resistance, and importantly, wetting-capability with non-flammable liquid-electrolytes. Here, we propose a concept of inorganic in-situ separator(IISS) by hybrid-sol physical crosslinking directly onto the electrode surface to address the above challenges. Particularly, the hybrid-sol is designed with silica nanoparticles as the building block and poly(vinylidene difluoride) nanoparticles as the crosslinking agent. The critical factors for controlling the IISS microstructures and properties have been systematically investigated. The advantages of the IISS have been confirmed by its fast wetting with various fireresistant liquid-electrolytes, customizable thickness and porous structures, robust interface with planar or three-dimensional(3D)-structured electrodes, and importantly, unexpected self-adaptability against puncturing. Enabled by the above merits, a fire-resistant ASLS-LIB is successfully assembled and demonstrated with stable electrochemical performance. This sol-crosslinked IISS may open an avenue for the studies on the next-generation separator technology, cell assembling, solid electrolyte processing as well as non-flammable secondary batteries.展开更多
The microstructured surface of materials were fabricated by a two-step acid-base catalyzed sol-gel process. In fluorinated polymer with PTFE doping, the well-proportioned composite sols were prepared using sol-gel pro...The microstructured surface of materials were fabricated by a two-step acid-base catalyzed sol-gel process. In fluorinated polymer with PTFE doping, the well-proportioned composite sols were prepared using sol-gel processing under the hydrochloric acid and deficiency of water conditions. After the substrate was coated by composite sols, and the gelation treatment on the surface of composite coating, the micrometer-scale and nanometer-scale hierarchical structures were formed in surface layer of material. XPS and TEM technologies were employed to identify that the gelation occurs just on the surface of composite coating. The morphology of coating surface was observed by SEM and AFM technologies. The microstructured surface of material can be fabricated using this inexpensive and easily controlled method on low surface energy resin materials, the super-hydrophobic coatings materials can be prepared.展开更多
Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when ...Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.展开更多
The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, ba...The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, balk salt ion concentration, incubation time and pH value on gelation were investigated. It has been observed that there was a gel strength maximum when the mass ratio was 0.6, the mixed temperature was 70°C, the balk salt ion concentration was 1.0 mol·L?1, the incubation time was 30 min and the pH value was 8. Interaction between molecules of these two polysaccharides was investigated by FT-IR spectrometry. Key words cationic guar gum - sodium alginate - gelation - synergism CLC number O 629.12 Foundation item: Supported by the National Natural Science Foundation of China(29574173)Biography: He Dong-bao (1945-), male, Associate professor, research direction: modifying and gelating of natural polysaccharides.展开更多
The development of a convenient methodology for synthesizing the hierarchically porous aerogels comprising metal–organic frameworks(MOFs)and graphene oxide(GO)building blocks that exhibit an ultralow density and unif...The development of a convenient methodology for synthesizing the hierarchically porous aerogels comprising metal–organic frameworks(MOFs)and graphene oxide(GO)building blocks that exhibit an ultralow density and uniformly distributed MOFs on GO sheets is important for various applications.Herein,we report a facile route for synthesizing MOF/reduced GO(rGO)aerogels based on the gelation of GO,which is directly initiated using MOF crystals.Free metal ions exposed on the surface of MIL-88A nanorods act as linkers that bind GO nanosheets to a three-dimensional porous network via metal–oxygen covalent or electrostatic interactions.The MOF/rGOderived magnetic and dielectric aerogels Fe_(3)O_(4)@C/rGO and Ni-doped Fe_(3)O_(4)@C/rGO show notable microwave absorption(MA)performance,simultaneously achieving strong absorption and broad bandwidth at low thickness of 2.5(-58.1 dB and 6.48 GHz)and 2.8 mm(-46.2 dB and 7.92 GHz)with ultralow filling contents of 0.7 and 0.6 wt%,respectively.The microwave attenuation ability of the prepared aerogels is further confirmed via a radar cross-sectional simulation,which is attributed to the synergistic effects of their hierarchically porous structures and heterointerface engineering.This work provides an effective pathway for fabricating hierarchically porous MOF/rGO hybrid aerogels and offers magnetic and dielectric aerogels for ultralight MA.展开更多
In this paper, the gelation mechanism of erythromycin ethylsuccinate(EES) during crystallization is investigated for the first time. The generated semisolid gel-like phase exhibited a 3D fibrillar network morphology a...In this paper, the gelation mechanism of erythromycin ethylsuccinate(EES) during crystallization is investigated for the first time. The generated semisolid gel-like phase exhibited a 3D fibrillar network morphology and the typical rheological properties of gels. The fibers inside the gel-like phase were confirmed to be new types of EES solvates using powder X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, and gas chromatography. The gelation and crystallization regions in EES-1-propanol solid–liquid phase diagram were determined. Analyses of solvent parameters showed that moderate solvent polarity may promote EES gelation. Fourier transform infrared spectra, nuclear magnetic resonance spectra, and scanning electron microscopy analyses indicated that through intermolecular hydrogen bonds, EES and solvent molecules assembled into fibers via crystallographic mismatch branching growth. The fibers intertwined into a 3D network microstructure and formed a gel-like phase, completely immobilizing the solution.展开更多
Unlike the adverse eff ect caused by the gelation during crystallization process, gelation of cefpiramide sodium was found to provide ideal product properties, such as a larger and more regular crystal shape. The caus...Unlike the adverse eff ect caused by the gelation during crystallization process, gelation of cefpiramide sodium was found to provide ideal product properties, such as a larger and more regular crystal shape. The causes of the gelation phenomenon and the mechanism of gel-crystal transition during the crystallization of cefpiramide sodium were both investigated in this work. The gel was formed due to the strapping of the solvents by the networks of cefpiramide sodium molecules. The whole gel-crystal transition process was divided into the following three stages:(1) when the temperature decreased, the system reached a metastable-state gelation;(2) the initial microcrystal in the gel grew slowly because of the low supersaturation;and (3) the gel fi nally disappeared, and a larger and more regular crystal was formed. The Hansen solubility parameters were used to analyze the eff ects of the solvents on this gelation;the analysis results can serve as guidance for solvent screening in the actual production process.展开更多
Alginate has been widely used in cell microencapsulation and drug delivery systems in the form of gel beads or microcapsules.Although an alternative novel emulsification-internal gelation technology has been establish...Alginate has been widely used in cell microencapsulation and drug delivery systems in the form of gel beads or microcapsules.Although an alternative novel emulsification-internal gelation technology has been established and both the properties and the potential applications of the beads in drug delivery systems have been studied,the mechanism has not been well understood compared with the traditional droplet method（external gelation technology）.On the basis of our previous knowledge that the novel technology is composed of complicatedly consecutive processes with multistep diffusion and reaction,and the diffusion of acetic acid across oil/water interface being the prerequisite that determines the occurrence and rate for the reactions and the structures and properties of final produced gel beads,a special emphasis was placed on the diffusion process.With the aid of diffusion modeling and simple experimental design,the diffusion rate constant and diffusion coefficient of acetic acid across oil/water interface were determined to be in the orders of magnitude of 10-6 and 10-16,respectively.This knowledge will be of particular importance in understanding and interpreting the formation,structure of the gel beads and the relationship between the structure and properties and guiding the preparation and quality control of the gel beads.展开更多
Conventional or traditional methods for the use of food processing have been outperformed by novel approaches recently. One such promising technology is ultra-sonication and recent studies have shown better effects in...Conventional or traditional methods for the use of food processing have been outperformed by novel approaches recently. One such promising technology is ultra-sonication and recent studies have shown better effects in physical characteristics of food which are induced by ultrasound. The previous researches further emphasize that the introduction of ultra-sonication on dairy proteins has resulted in the improvement of their structural, physical and chemical properties while it is widely used in hydrocolloid systems to accelerate the gelation process. Therefore this theory could be useful for the gelation of milk proteins in the presence of a polysaccharide. After discussing briefly on hydrocolloids and the theory of ultrasound, the possibility and the impact of ultrasound on gelation of milk protein mixtures with Carrageenan is highlighted in this study. The inherent characteristics of both milk proteins and carrageenan and properties of the ultrasound treatment have cumulatively effect on gelation. Therefore, there is a necessity to develop specific variables depending on the type of dairy product.展开更多
To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adeq...To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adequate passivation capability is important. To achieve enough conductivity and effective hole extraction, spiro-OMe TAD, one of the most frequently used HTL in optoelectronic devices, often needs chemical doping with a lithium compound(LiTFSI). However, the lithium salt dopant induces crystallization and has a negative impact on the performance and lifetime of the device due to its hygroscopic nature. Here, we provide an easy method for creating a gel by mixing a natural small molecule additive(thioctic acid, TA) with spiro-OMe TAD. We discover that gelation effectively improves the compactness of resultant HTL and prevents moisture and oxygen infiltration. Moreover, the gelation of HTL improves not only the conductivity of spiro-OMe TAD, but also the operational robustness of the devices in the atmospheric environment. In addition, TA passivates the perovskite defects and facilitates the charge transfer from the perovskite layer to HTL. As a consequence, the optimized PSCs based on the gelated HTL exhibit an improved PCE(22.52%) with excellent device stability.展开更多
In tofu making by heat treatment, the addition of coagulant ionizes the proteins as a result of heat dissolution and the ionized proteins aggregate with the coagulant to form protein clusters. The electrical conductiv...In tofu making by heat treatment, the addition of coagulant ionizes the proteins as a result of heat dissolution and the ionized proteins aggregate with the coagulant to form protein clusters. The electrical conductivity (EC) of the soya milk emulsion varies in response to the progress of gelation. By ohmic heating, the applied current and voltage directly indicate the electrical conductivity of the soya milk emulsion and then indirectly the progress of tofu gelation. In this paper, ultrasonic measurement is adopted to explore the feasibility of using EC as an indicator of tofu gelation. Experiments showed a strong correlation between EC and ultrasonic measurement in characterisation of tofu gelation.展开更多
An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarize...An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest.展开更多
We propose an irreversible binary coagulation model with a constant-reaction-number kernel, in which, among all the possible binary coagulation reactions, only p reactions are permitted to take place at every time. By...We propose an irreversible binary coagulation model with a constant-reaction-number kernel, in which, among all the possible binary coagulation reactions, only p reactions are permitted to take place at every time. By means of the generalized rate equation we investigate the kinetic behaviour of the system with the reaction rate kernel K（i;j） = （ij）^w （0 ≤w〈1/2）, at which an i-mer and a j-mer coagulate together to form a large one. It is found that for such a system there always exists a gelation transition at a finte time to, which is in contrast to the ordinary binary coagulation with the same rate kernel. Moreover, the pre-gelation behaviour of the cluster size distribution near the gelation point falls in a scaling regime and the typical cluster size grows as （to - t）-1/（1-2w）. On the other hand, our model can also provide some predictions for the evolution of the cluster distribution in multicomponent complex networks.展开更多
Dynamic viscoelastic properties of polyacrylonitrile(PAN)/DMSO/H2O solutions with different H2O contents were studied as a function of temperature.These PAN solutions gradually became gel with decreasing temperature.T...Dynamic viscoelastic properties of polyacrylonitrile(PAN)/DMSO/H2O solutions with different H2O contents were studied as a function of temperature.These PAN solutions gradually became gel with decreasing temperature.The sol-gel transition took place at a critical gel temperature,at which the scaling law of G'(ω)～G″(ω)∝ωn held,allowing an accurate determination of the critical gel temperature by means of the frequency independence of the loss tangent.The gel point of PAN solutions increases with increasing H2O content.The scaling exponent n(=0.86) at the gel point is confirmed to be universal for PAN gels,which is independent of temperature,suggesting the similarity of the fractal structure in the critical PAN gels.展开更多
Influence of non-gelling methylcellulose （MC） on gelation behavior of wheat gliadins in 13 wt% alkaline propanol/water （50：50, v/v） solution was investigated using dynamic theological time sweep test. Increasing ...Influence of non-gelling methylcellulose （MC） on gelation behavior of wheat gliadins in 13 wt% alkaline propanol/water （50：50, v/v） solution was investigated using dynamic theological time sweep test. Increasing MC concentration （CMC） up to CMC = 1 wt% caused a significant reduction in gelation time （tget） of the solution and an increase in loss tangent （tan δ） value of the resultant gel at T 〈 30 ℃.展开更多
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.
文摘In-situ gelation of aqueous sulfomethylated resorcinol formaldehyde (SMRF) system inBerea core has been investigated. Two sets of displacement experiments were conducted with thissystem (containing 5% NaCl, 0. 036% CaCl_2. 2H_2O). The brine permeabilities of the coreswere reduced significantly from about 600 to 0.1 md. The in-situ gelation in Berea core occurreda little bit earlier than gelation anticipated from bulk test in the experiments. The gel time waseasier to control at initial pH between 6 and 8. During injection of SMRF system, the apparentviscosity was less than 1 mPa·s at 41℃.
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financially supported by the National Natural Science Foundation of China(Nos.52404328,52274412,and 52374418)the China Postdoctoral Science Foundation(No.2024M753248)。
文摘The rich resources and unique environment of the Moon make it an ideal location for human expansion and the utilization of extraterrestrial resources.Oxygen,crucial for supporting human life on the Moon,can be extracted from lunar regolith,which is highly rich in oxygen and contains polymetallic oxides.This oxygen and metal extraction can be achieved using existing metallurgical techniques.Furthermore,the ample reserves of water ice on the Moon offer another means for oxygen production.This paper offers a detailed overview of the leading technologies for achieving oxygen production on the Moon,drawing from an analysis of lunar resources and environmental conditions.It delves into the principles,processes,advantages,and drawbacks of water-ice electrolysis,two-step oxygen production from lunar regolith,and one-step oxygen production from lunar regolith.The two-step methods involve hydrogen reduction,carbothermal reduction,and hydrometallurgy,while the one-step methods encompass fluorination/chlorination,high-temperature decomposition,molten salt electrolysis,and molten regolith electrolysis(MOE).Following a thorough comparison of raw materials,equipment,technology,and economic viability,MOE is identified as the most promising approach for future in-situ oxygen production on the Moon.Considering the corrosion characteristics of molten lunar regolith at high temperatures,along with the Moon's low-gravity environment,the development of inexpensive and stable inert anodes and electrolysis devices that can easily collect oxygen is critical for promoting MOE technology on the Moon.This review significantly contributes to our understanding of in-situ oxygen production technologies on the Moon and supports upcoming lunar exploration initiatives.
基金funded by the Basic Scientific Fund for National Public Research Institutes of China(No.2022 S01)the National Natural Science Foundation of China(Nos.42176191,42049902,and U22A2012)+5 种基金the Shandong Provincial Natural Science Foundation,China(No.ZR2022YQ40)the National Key R&D Program of China(No.2021YFF0501202)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(No.SML2023 SP232)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.241gqb006)Data acquisition and sample collections were supported by the National Natural Science Foundation of China Open Research Cruise(Cruise No.NORC2021-02+NORC2021301)funded by the Shiptime Sharing Project of the National Natural Science Foundation of China。
文摘Accurate acquisition and prediction of acoustic parameters of seabed sediments are crucial in marine sound propagation research.While the relationship between sound velocity and physical properties of sediment has been extensively studied,there is still no consensus on the correlation between acoustic attenuation coefficient and sediment physical properties.Predicting the acoustic attenuation coefficient remains a challenging issue in sedimentary acoustic research.In this study,we propose a prediction method for the acoustic attenuation coefficient using machine learning algorithms,specifically the random forest(RF),support vector machine(SVR),and convolutional neural network(CNN)algorithms.We utilized the acoustic attenuation coefficient and sediment particle size data from 52 stations as training parameters,with the particle size parameters as the input feature matrix,and measured acoustic attenuation as the training label to validate the attenuation prediction model.Our results indicate that the error of the attenuation prediction model is small.Among the three models,the RF model exhibited the lowest prediction error,with a mean squared error of 0.8232,mean absolute error of 0.6613,and root mean squared error of 0.9073.Additionally,when we applied the models to predict the data collected at different times in the same region,we found that the models developed in this study also demonstrated a certain level of reliability in real prediction scenarios.Our approach demonstrates that constructing a sediment acoustic characteristics model based on machine learning is feasible to a certain extent and offers a novel perspective for studying sediment acoustic properties.
基金National Natural Science Foundation of China (52203123)Sichuan Science and Technology Program (2023NSFSC0991)+2 种基金State Key Laboratory of Polymer Materials Engineering (sklpme-2023-1-05 and sklpme-2024-2-04)Fundamental Research Funds for the Central UniversitiesThis research was also partially sponsored by the Double First-Class Construction Funds of Sichuan University。
文摘All-safe liquid-state lithium-ion batteries(ASLS-LIBs) is of great interest as they can potentially combine the safety of all-solid-state batteries with the high performance and low manufacturing cost of traditional liquid-state LIBs. However, the practical success of ASLS-LIBs is bottlenecked by the lack of advanced separator technology that can simultaneously realize high performances in puncturing-tolerability,fire-resistance, and importantly, wetting-capability with non-flammable liquid-electrolytes. Here, we propose a concept of inorganic in-situ separator(IISS) by hybrid-sol physical crosslinking directly onto the electrode surface to address the above challenges. Particularly, the hybrid-sol is designed with silica nanoparticles as the building block and poly(vinylidene difluoride) nanoparticles as the crosslinking agent. The critical factors for controlling the IISS microstructures and properties have been systematically investigated. The advantages of the IISS have been confirmed by its fast wetting with various fireresistant liquid-electrolytes, customizable thickness and porous structures, robust interface with planar or three-dimensional(3D)-structured electrodes, and importantly, unexpected self-adaptability against puncturing. Enabled by the above merits, a fire-resistant ASLS-LIB is successfully assembled and demonstrated with stable electrochemical performance. This sol-crosslinked IISS may open an avenue for the studies on the next-generation separator technology, cell assembling, solid electrolyte processing as well as non-flammable secondary batteries.
文摘The microstructured surface of materials were fabricated by a two-step acid-base catalyzed sol-gel process. In fluorinated polymer with PTFE doping, the well-proportioned composite sols were prepared using sol-gel processing under the hydrochloric acid and deficiency of water conditions. After the substrate was coated by composite sols, and the gelation treatment on the surface of composite coating, the micrometer-scale and nanometer-scale hierarchical structures were formed in surface layer of material. XPS and TEM technologies were employed to identify that the gelation occurs just on the surface of composite coating. The morphology of coating surface was observed by SEM and AFM technologies. The microstructured surface of material can be fabricated using this inexpensive and easily controlled method on low surface energy resin materials, the super-hydrophobic coatings materials can be prepared.
基金Supported by the National Natural Science Foundation of China ( No.2 95 74173)
文摘Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3%of total polysaccharide concentration with addtion of 12%NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry.
文摘The synergistic interaction between the cationic guar gum (the ammonium hydroxy-propyl-trimethyl chloride of guar gum) and sodium alginate has been studied. The effects of the mass ratio of them, mixed temperature, balk salt ion concentration, incubation time and pH value on gelation were investigated. It has been observed that there was a gel strength maximum when the mass ratio was 0.6, the mixed temperature was 70°C, the balk salt ion concentration was 1.0 mol·L?1, the incubation time was 30 min and the pH value was 8. Interaction between molecules of these two polysaccharides was investigated by FT-IR spectrometry. Key words cationic guar gum - sodium alginate - gelation - synergism CLC number O 629.12 Foundation item: Supported by the National Natural Science Foundation of China(29574173)Biography: He Dong-bao (1945-), male, Associate professor, research direction: modifying and gelating of natural polysaccharides.
基金the National Natural Science Foundation of China(52102361,62071239)Natural Science Foundation of Jiangsu Province(BK20200827)+1 种基金National Key Laboratory on Electromagnetic Environmental Effects and Electro-optical Engineering(JCKYS2022LD2)the Startup Foundation for Introducing Talent of NUIST。
文摘The development of a convenient methodology for synthesizing the hierarchically porous aerogels comprising metal–organic frameworks(MOFs)and graphene oxide(GO)building blocks that exhibit an ultralow density and uniformly distributed MOFs on GO sheets is important for various applications.Herein,we report a facile route for synthesizing MOF/reduced GO(rGO)aerogels based on the gelation of GO,which is directly initiated using MOF crystals.Free metal ions exposed on the surface of MIL-88A nanorods act as linkers that bind GO nanosheets to a three-dimensional porous network via metal–oxygen covalent or electrostatic interactions.The MOF/rGOderived magnetic and dielectric aerogels Fe_(3)O_(4)@C/rGO and Ni-doped Fe_(3)O_(4)@C/rGO show notable microwave absorption(MA)performance,simultaneously achieving strong absorption and broad bandwidth at low thickness of 2.5(-58.1 dB and 6.48 GHz)and 2.8 mm(-46.2 dB and 7.92 GHz)with ultralow filling contents of 0.7 and 0.6 wt%,respectively.The microwave attenuation ability of the prepared aerogels is further confirmed via a radar cross-sectional simulation,which is attributed to the synergistic effects of their hierarchically porous structures and heterointerface engineering.This work provides an effective pathway for fabricating hierarchically porous MOF/rGO hybrid aerogels and offers magnetic and dielectric aerogels for ultralight MA.
基金supported by the National Natural Science Foundation of China(Nos.21576187,21776203)
文摘In this paper, the gelation mechanism of erythromycin ethylsuccinate(EES) during crystallization is investigated for the first time. The generated semisolid gel-like phase exhibited a 3D fibrillar network morphology and the typical rheological properties of gels. The fibers inside the gel-like phase were confirmed to be new types of EES solvates using powder X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, and gas chromatography. The gelation and crystallization regions in EES-1-propanol solid–liquid phase diagram were determined. Analyses of solvent parameters showed that moderate solvent polarity may promote EES gelation. Fourier transform infrared spectra, nuclear magnetic resonance spectra, and scanning electron microscopy analyses indicated that through intermolecular hydrogen bonds, EES and solvent molecules assembled into fibers via crystallographic mismatch branching growth. The fibers intertwined into a 3D network microstructure and formed a gel-like phase, completely immobilizing the solution.
基金supported by Tianjin Municipal Natural Science Foundation (No. 16JCZDJC32700)Major National Scientifi c Instrument Development Project (No. 21527812)
文摘Unlike the adverse eff ect caused by the gelation during crystallization process, gelation of cefpiramide sodium was found to provide ideal product properties, such as a larger and more regular crystal shape. The causes of the gelation phenomenon and the mechanism of gel-crystal transition during the crystallization of cefpiramide sodium were both investigated in this work. The gel was formed due to the strapping of the solvents by the networks of cefpiramide sodium molecules. The whole gel-crystal transition process was divided into the following three stages:(1) when the temperature decreased, the system reached a metastable-state gelation;(2) the initial microcrystal in the gel grew slowly because of the low supersaturation;and (3) the gel fi nally disappeared, and a larger and more regular crystal was formed. The Hansen solubility parameters were used to analyze the eff ects of the solvents on this gelation;the analysis results can serve as guidance for solvent screening in the actual production process.
基金Supported by the National Natural Science Foundation of China(No.30472102)the National Basic Research Program ofChina(Nos.2002CB713804and2007CB714305).
文摘Alginate has been widely used in cell microencapsulation and drug delivery systems in the form of gel beads or microcapsules.Although an alternative novel emulsification-internal gelation technology has been established and both the properties and the potential applications of the beads in drug delivery systems have been studied,the mechanism has not been well understood compared with the traditional droplet method（external gelation technology）.On the basis of our previous knowledge that the novel technology is composed of complicatedly consecutive processes with multistep diffusion and reaction,and the diffusion of acetic acid across oil/water interface being the prerequisite that determines the occurrence and rate for the reactions and the structures and properties of final produced gel beads,a special emphasis was placed on the diffusion process.With the aid of diffusion modeling and simple experimental design,the diffusion rate constant and diffusion coefficient of acetic acid across oil/water interface were determined to be in the orders of magnitude of 10-6 and 10-16,respectively.This knowledge will be of particular importance in understanding and interpreting the formation,structure of the gel beads and the relationship between the structure and properties and guiding the preparation and quality control of the gel beads.
文摘Conventional or traditional methods for the use of food processing have been outperformed by novel approaches recently. One such promising technology is ultra-sonication and recent studies have shown better effects in physical characteristics of food which are induced by ultrasound. The previous researches further emphasize that the introduction of ultra-sonication on dairy proteins has resulted in the improvement of their structural, physical and chemical properties while it is widely used in hydrocolloid systems to accelerate the gelation process. Therefore this theory could be useful for the gelation of milk proteins in the presence of a polysaccharide. After discussing briefly on hydrocolloids and the theory of ultrasound, the possibility and the impact of ultrasound on gelation of milk protein mixtures with Carrageenan is highlighted in this study. The inherent characteristics of both milk proteins and carrageenan and properties of the ultrasound treatment have cumulatively effect on gelation. Therefore, there is a necessity to develop specific variables depending on the type of dairy product.
基金supported by the National Natural Science Foundation of China (21975028, U21A20172 and 22011540377)the Special Key Projects (2022-JCJQ-ZD-224-12)。
文摘To achieve high power conversion efficiency(PCE) and long-term stability of perovskite solar cells(PSCs), a hole transport layer(HTL) with persistently high conductivity, good moisture/oxygen barrier ability, and adequate passivation capability is important. To achieve enough conductivity and effective hole extraction, spiro-OMe TAD, one of the most frequently used HTL in optoelectronic devices, often needs chemical doping with a lithium compound(LiTFSI). However, the lithium salt dopant induces crystallization and has a negative impact on the performance and lifetime of the device due to its hygroscopic nature. Here, we provide an easy method for creating a gel by mixing a natural small molecule additive(thioctic acid, TA) with spiro-OMe TAD. We discover that gelation effectively improves the compactness of resultant HTL and prevents moisture and oxygen infiltration. Moreover, the gelation of HTL improves not only the conductivity of spiro-OMe TAD, but also the operational robustness of the devices in the atmospheric environment. In addition, TA passivates the perovskite defects and facilitates the charge transfer from the perovskite layer to HTL. As a consequence, the optimized PSCs based on the gelated HTL exhibit an improved PCE(22.52%) with excellent device stability.
文摘In tofu making by heat treatment, the addition of coagulant ionizes the proteins as a result of heat dissolution and the ionized proteins aggregate with the coagulant to form protein clusters. The electrical conductivity (EC) of the soya milk emulsion varies in response to the progress of gelation. By ohmic heating, the applied current and voltage directly indicate the electrical conductivity of the soya milk emulsion and then indirectly the progress of tofu gelation. In this paper, ultrasonic measurement is adopted to explore the feasibility of using EC as an indicator of tofu gelation. Experiments showed a strong correlation between EC and ultrasonic measurement in characterisation of tofu gelation.
文摘An improved rheo-optic in situ synchronous measurement system was employed to investigate the gelation behaviour and mechanism of waxy crude oil emulsions. By combining transmitted natural light and reflected polarized light microscopy, a multiangle composite light source was built to achieve the simultaneous observation of wax crystals and emulsified water droplets, as well as their dynamic aggregation process. Main outcomes on the microscopic mechanism were obtained by developed microscopic image processing method. It was found that the microstructure of W/O waxy crude oil emulsion has the evolution of “individual structure--homogeneous aggregate structure--heterogeneous coaggregate structure--floc structure” during the static cooling, which results in the four stages during gelation process. Different from previous studies, the aggregation of emulsified water droplets was found to be more significant and contributes to the formation and development of the wax crystals-emulsified water droplets coaggregate, which plays a decisive role in the further evolution of the gelled microstructure. Time series microscopic images show the dynamic aggregation of emulsified water droplets and wax crystals. Two different aggregation behaviours between wax crystals and water droplets were observed. That wax crystals can not only embed in gaps between adjacent water droplets and enhance the structure, but also surround the outside of the water droplets and continue to grow resulting in the interconnection of different coaggregates to form a larger floc structure. In addition, correlation between viscoelasticity and microstructure evolution of waxy crude oil emulsions of different water contents was discussed. With increasing water contents, the microstructure is changed from wax crystal flocculation structure as the main skeleton and the emulsified water droplets embedded in it, into the aggregation of emulsified water droplets occupying the main position. When the number of wax crystals and water droplets reaches a certain ratio, did wax crystals form coaggregates with emulsified water droplets, and the remaining wax crystals formed an overall flocculation structure, the viscoelasticity of the waxy crude oil emulsion is the highest.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10305009 and 10275048, and the Zhejiang Provincial Natural Science Foundation of China under Grant No 102067.
文摘We propose an irreversible binary coagulation model with a constant-reaction-number kernel, in which, among all the possible binary coagulation reactions, only p reactions are permitted to take place at every time. By means of the generalized rate equation we investigate the kinetic behaviour of the system with the reaction rate kernel K（i;j） = （ij）^w （0 ≤w〈1/2）, at which an i-mer and a j-mer coagulate together to form a large one. It is found that for such a system there always exists a gelation transition at a finte time to, which is in contrast to the ordinary binary coagulation with the same rate kernel. Moreover, the pre-gelation behaviour of the cluster size distribution near the gelation point falls in a scaling regime and the typical cluster size grows as （to - t）-1/（1-2w）. On the other hand, our model can also provide some predictions for the evolution of the cluster distribution in multicomponent complex networks.
基金Project(2006CB606505) supported by the National Basic Research Development Program of ChinaProject(50333050) supported by the National Natural Science Foundation of China+1 种基金Project(07DJ14002) supported by the Shanghai Fundamental Theory ProgramProject(20020255010) supported by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘Dynamic viscoelastic properties of polyacrylonitrile(PAN)/DMSO/H2O solutions with different H2O contents were studied as a function of temperature.These PAN solutions gradually became gel with decreasing temperature.The sol-gel transition took place at a critical gel temperature,at which the scaling law of G'(ω)～G″(ω)∝ωn held,allowing an accurate determination of the critical gel temperature by means of the frequency independence of the loss tangent.The gel point of PAN solutions increases with increasing H2O content.The scaling exponent n(=0.86) at the gel point is confirmed to be universal for PAN gels,which is independent of temperature,suggesting the similarity of the fractal structure in the critical PAN gels.
基金supported by the National Natural Science Foundation of China(No.50773068)Natural Science Foundation of Zhejiang Province(No.Y407011).
文摘Influence of non-gelling methylcellulose （MC） on gelation behavior of wheat gliadins in 13 wt% alkaline propanol/water （50：50, v/v） solution was investigated using dynamic theological time sweep test. Increasing MC concentration （CMC） up to CMC = 1 wt% caused a significant reduction in gelation time （tget） of the solution and an increase in loss tangent （tan δ） value of the resultant gel at T 〈 30 ℃.
