Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions o...Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions often exhibit inferior stability compared to their aqueous counterparts.In this experiment,the properties of quaternary ammonium surfactants in glycerol were investigated through surface tension measurements,to further enhance the stability of n-decane/glycerol emulsions,hydrophilic nanoparticles SiO_(2) were modified in situ using double tailed quaternary ammonium surfactants Di-C_(12)DAB and Di-C_(16)DAB.Stable n-decane/glycerol Pickering emulsions were successfully prepared.These emulsions were stable at 45℃for over six months,and no significant changes in droplet size occurred.The minimum droplet size of the emulsion was only 2-3μm.Contact angle measurements showed that the wettability of the silica surface was tremendously affected by the concentration and the alkyl chain length of the double-tailed surfactants.In the presence of Di-C_(12)DAB,the contact angle of glycerol on the silica surface increased monotonically with the surfactant concentration.This explains the phenomenon that the Pickering emulsions containing Di-C_(12)DAB and silica particles were stable within the contact angle range of 80°-120°.Comparatively,the contact angle of the glycerol on the silica surface in the presence of Di-C_(16)DAB first increased with surfactant concentrations and then decreased,reaching a maximum at 0.6 mmol/L.It can be concluded that Di-C_(12)DAB formed monolayers at the surface of silica particles within all investigated concentrations.On the contrary,Di-C_(16)DAB formed monolayers at concentrations below 0.6 mmol/L and formed double layers at concentrations above 0.6 mmol/L,leading to a non-monotonic change in the contact angle with respect to concentration.Using these stable non-aqueous Pickering emulsions as templates,polymer microspheres with a particle size of 2-3μm were successfully prepared with high yield.This work is helpful to expand the potential applications of non-aqueous emulsions in the encapsulation of drug,controlled release,material preparation,and cosmetic formulations.展开更多
The stability of acid-crude oil emulsion poses manifold issues in the oil industry.Experimentally evaluating this phenomenon may be costly and time-consuming.In contrast,machine learning models have proven effective i...The stability of acid-crude oil emulsion poses manifold issues in the oil industry.Experimentally evaluating this phenomenon may be costly and time-consuming.In contrast,machine learning models have proven effective in predicting and evaluating various phenomena.This research is the first of its kind to assess the stability of acid-crude oil emulsion,employing various classification machine learning models.For this purpose,a data set consisting of 249 experimental data points belonging to 11 different crude oil samples was collected.Three tree-based models,namely decision tree(DT),random forest(RF),and categorical boosting(CatBoost),as well as three artificial neural network models,namely radial basis function(RBF),multi-layer perceptron(MLP) and convolutional neural network(CNN),were developed based on the properties of crude oil,acid,and protective additive.The CatBoost model obtained the highest accuracy with 0.9687,followed closely by the CNN model with 0.9673.In addition,confusion matrix findings showed the superiority of the CatBoost model.Finally,by applying the SHapley Additive exPlanations(SHAP) method to analyze the impact of input parameters,it was found that the crude oil viscosity has the most significant effect on the model's output with the mean absolute SHAP value of 0.88.展开更多
During oil displacement,surfactants often encounter challenges such as emulsion instability and channeling,which can compromise their efficiency.To address these issues,polymer microspheres were synthesized via revers...During oil displacement,surfactants often encounter challenges such as emulsion instability and channeling,which can compromise their efficiency.To address these issues,polymer microspheres were synthesized via reverse microemulsion polymerization using acrylamide,2-methyl-2-acrylamidopropane sulfonic acid,and stearyl methacrylate as monomers,with N,N-methylenebisacrylamide as the crosslinker.The microspheres were then combined with sodium alkyl alcohol polyoxyethylene ether carboxylate to enhance emulsion stability and expand the swept volume of surfactant.A stable reverse microemulsion system was prepared using the maximum water solubilization rate as the indicator,and microspheres were synthesized based on this system.The ability of the microspheres to enhance emulsion stability was systematically evaluated.The plugging performance and enhanced oil recovery(EOR)efficiency of the microsphere/surfactant composite system were assessed through core seepage and oil displacement experiments.The experimental results demonstrated that microspheres were successfully prepared in a water-in-oil reverse microemulsion system with a solubilization rate of 42%.The emulsion stability was evaluated under an oil-to-water ratio of 7:3,a temperature of 80℃,and a salinity of 44,592 mg/L,by manually shaking the test tube five times.It was observed that the complete phase separation time of the emulsion increased from 10 to 120 min after the addition of microspheres.Under different permeability conditions(100×10^(-3),300×10^(-3),500×10^(-3)μm^(2)),the recovery efficiency of the composite system increased by 4.5%,8.3%,and 4.8%,respectively,compared to a single surfactant system.The microspheres developed in this study enhanced emulsion stability and increased the swept volume of surfactant within the formation,significantly boosting its oil recovery efficiency.展开更多
The chloride penetration resistance of cement-based grout materials was improved by nano-silica emulsion.Specimens of mixtures containing different nano-silica particles or emulsions were exposed in sodium chloride so...The chloride penetration resistance of cement-based grout materials was improved by nano-silica emulsion.Specimens of mixtures containing different nano-silica particles or emulsions were exposed in sodium chloride solutions of specific concentrations with different test ages.Hardened properties of the mixes were assessed in terms of weight loss and compressive strength.X-ray diffraction(XRD)and scanning electron microscopy(SEM)of mixes were performed to analysis the phase evolution and microstructure.The results demonstrated that the introduction of nano-SiO_(2) emulsion significantly decreased the compressive strength loss and calcium hydroxide(CH)crystal content of hydration production,and then enhanced the resistance of cement-based grouting materials to chloride ion penetration.This improvement derives from the filling and pozzolanic effects of nano-SiO_(2) particles,which were incorporated via an emulsion and attributed to a well dispersion in grouting matrix.展开更多
Naturally degradable capsule provides a platform for sustained fragrance release.However,practical challenges such as low encapsulation efficiency and difficulty in sustained release are still limited in using fragran...Naturally degradable capsule provides a platform for sustained fragrance release.However,practical challenges such as low encapsulation efficiency and difficulty in sustained release are still limited in using fragranceloaded capsules.In this work,the natural materials sodium alginate and gelatine are dissolved and act as the aqueous phase,lavender is dissolved in caprylic/capric triglyceride(GTCC)as the oil phase,and SiO_(2) nanoparticles with neutralwettability as a solid emulsifier to form O/W Pickering emulsions simultaneously.Finally,multi-core capsules are prepared using the drop injection method with emulsions as templates.The results show that the capsules have been successfully prepared with a spherical morphology and multi-core structure,and the encapsulation rate of multi-core capsules can reach up to 99.6%.In addition,the multi-core capsules possess desirable sustained release performance,the cumulative sustained release rate of fragrance at 25℃over 49 days is only 32.5%.It is attributed to the significant protection of multi-core structure,Pickering emulsion nanoparticle membranes,and hydrogel network shell for encapsulated fragrance.This study is designed to deliver a new strategy for using sustained-release technology with fragrance in food,cosmetics,textiles,and other fields.展开更多
As a natural oil-soluble emulsifier to replace Polyglycerol Polyricinoleate(PGPR),lecithin's application in double emulsions(DEs)remains constrained due to low encapsulation efficiency and stability,while incorpor...As a natural oil-soluble emulsifier to replace Polyglycerol Polyricinoleate(PGPR),lecithin's application in double emulsions(DEs)remains constrained due to low encapsulation efficiency and stability,while incorporating Pickering particles within the inner aqueous phase(W_(1))has emerged as an effective approach to enhance DEs stability.However,the interfacial interactions between Pickering particles in W_(1) and lecithin in oil phase and their effects on the physical,delivery and digestion properties of DEs remain to be explored.In this study,a natural Pickering DEs encapsulating blueberry anthocyanins(ANCs)was developed using lecithin and gliadinbased particles,with gliadin colloid particles(GCPs)introduced into W_(1).The effects of GCP concentration in W_(1) on emulsion droplet size,microstructure,W_(1)/O interfacial rheology,in vitro digestion,and ANCs delivery performance were systematically investigated.Results showed that GCPs in W_(1) accelerated the decreasing of W_(1)/O interfacial tension,indicating that,beyond competitive adsorption,combination between the two might also occur at the interface,which could accelerate the interfacial adsorption of lecithin.GCPs significantly improved the strength of the W_(1)/O interface,thus improving ANCs encapsulation efficiency from 49.66%to 70.60%.Moreover,the droplet size of DEs decreased from 38.94μm to 24.09μm as GCPs concentration increased,indicating that some GCPs might transfer to the outer aqueous phase through phase exchange,acting as hydrophilic emulsifiers.GCPs in W_(1) can modulate ANCs in vitro release,enhancing ANCs'bioaccessibility(31.10%)and antioxidant capacity.展开更多
Poly(octamethylene citrate)(POC)is a promising bioelastomer material in the biomedical field.However,its thermosetting nature poses a significant challenge to processing and molding,especially manufacturing the POC-ba...Poly(octamethylene citrate)(POC)is a promising bioelastomer material in the biomedical field.However,its thermosetting nature poses a significant challenge to processing and molding,especially manufacturing the POC-based elastomer particles as potential,degradable and toughened fillers.Firstly,a Pickering emulsion with a pre-polymer(pre-POC)solution in dimethyl carbonate as a dispersed oil phase,a Pullulan(PUL)aqueous solution as a continuous water phase,and chitin nanocrystal(ChiNC)as a particle-type emulsifier was constructed.Secondly,the POC-based core/shell structured microspheres were prepared by spray-drying of the emulsions,and characterized by a scanning electron microscope and a transmission electron microscope.Finally,the POC-based core/shell structured microspheres were used as elastomer fillers to strengthen and toughen a chitosan film,resulting in 26%increase in the tensile strength and 45%increase in the strain at break;the POC-based core/shell structured microsphere as a double-layer drug release system was built in which the hydrophilic drug of tetracycline hydrochloride(TCH)was released from the outer layer and the hydrophobic drug of curcumin was released from the inner layer,roughly following the Ritger-Peppas model.展开更多
Flexible and conformable nanomaterial-based functional hydrogels find promising applications in various fields.However,the controllable manipulation of functional electron/mass transport networks in hydrogels remains ...Flexible and conformable nanomaterial-based functional hydrogels find promising applications in various fields.However,the controllable manipulation of functional electron/mass transport networks in hydrogels remains rather challenging to realize.We describe a general and versatile surfactant-free emulsion construction strategy to customize robust functional hydrogels with programmable hierarchical structures.Significantly,the amphipathy of silk fibroin(SF)and the reinforcement effect of MXene nanosheets produce sable Pickering emulsion without any surfactant.The followed microphase separation and self-cross-linking of the SF chains induced by the solvent exchange convert the composite emulsions into high-performance hydrogels with tunable microstructures and functionalities.As a proof-of-concept,the controllable regulation of the ordered conductive network and the water polarization effect confer the hydrogels with an intriguing electromagnetic interference shielding efficiency(~64 dB).Also,the microstructures of functional hydrogels are modulated to promote mass/heat transfer properties.The amino acids of SF and the surface terminations of MXene help reduce the enthalpy of water evaporation and the hierarchical structures of the hydrogels accelerate evaporation process,expecting far superior evaporation performance(~3.5 kg m^(-2)h^(-1))and salt tolerance capability compared to other hydrogel evaporators.Our findings open a wealth of opportunities for producing functional hydrogel devices with integrated structure-dependent properties.展开更多
Stable HCl-crude oil emulsion and its subsequent sludge formation,with detrimental impacts on oil production,may stem from acid stimulation.One major ambiguity in this process is to discern the most influential compon...Stable HCl-crude oil emulsion and its subsequent sludge formation,with detrimental impacts on oil production,may stem from acid stimulation.One major ambiguity in this process is to discern the most influential component of crude oil on the stability of formed emulsions.This fundamental question has not adequately been addressed in previous studies.In this work,the impact of de-asphalted part of crude oil(maltene)has been investigated on the acid-induced emulsion and sludge separately.Accordingly,the emulsion phase separation and the amount of formed sludge have been compared for four crude oils and their maltene samples for different concentrations of ferric ion and acidic pH values.The results of phase separation,as a criterion for emulsion stability,showed that crude oil samples formed 6 to 25 percent more stable emulsions than maltene samples,when using blank HCl.The emulsions of maltene and spent acid(pH=2)broke completely during the first 15 min after emulsification.In addition,the maltene components usually had less contribution to sludge formation in the presence of blank HCl.It was concluded that asphaltene is the key component during interaction with HCl.However,the maltene of one crude sample formed higher acid sludge in comparison to its crude oil.For acid solutions containing 3000 ppm of ferric ion,the emulsion stability increased for all crude oil and maltene samples.Moreover,the stability of some maltene emulsions increased to 48%and 100%in the presence of 3000 ppm of ferric ions.The presence of ferric ions caused forming very stable emulsions,while most of the sludge formation took place at higher pH values.Finally,it was also attained that emulsion and sludge formations could happen simultaneously.展开更多
This study prepared and characterized amphiphilic carboxymethyl cellulose stearate(CMCS)recycled from sugarcane bagasse agro-waste(SB).The Fourier-transform infrared(FTIR)analysis confirmed cellulose,carboxymethyl cel...This study prepared and characterized amphiphilic carboxymethyl cellulose stearate(CMCS)recycled from sugarcane bagasse agro-waste(SB).The Fourier-transform infrared(FTIR)analysis confirmed cellulose,carboxymethyl cellulose(CMC),and CMCS structures,with CMCS showing increased H-bonding.X-ray diffraction analysis(XRD)revealed reduced crystallinity in CMC and CMCS.CMCS exhibited a hydrophobic nature but dispersed in water,enabling nanoemulsion formation.Optimal nanoemulsion was achieved with CMCS1,showing a particle size of 99 nm.Transmission electron microscopy(TEM)images revealed CMC’s honeycomb structure,transforming into spherical particles in CMCS1.Antimicrobial tests demonstrated strong activity of CMCS formulations against Escherichia coli and Staphylococcus aureus,with CMCS3 exhibiting the highest efficacy.These findings highlight the potential of CMCS-based nanoemulsions for antimicrobial applications and nanoemulsification.展开更多
Copolymers of fluoroethylene and vinyl ethers(FEVE)are soluble and curable at relatively low temperature,and are used as high-performance coatings and paints.Currently,most market-available FEVE products obtained thro...Copolymers of fluoroethylene and vinyl ethers(FEVE)are soluble and curable at relatively low temperature,and are used as high-performance coatings and paints.Currently,most market-available FEVE products obtained through solution polymerization contain a large fraction of organic solvent,and hence,volatile organic compound(VOC)emissions cause environmental issues.In this study,the emulsion copolymerization of chlorotrifluoroethylene(CTFE)and vinyl ethers using an environmentally friendly emulsification system to produce waterborne FEVE was investigated.In addition to mixed nonionic and ionic surfactants,macromolecular monomer with double bond and polyoxyethylene segments were used in the emulsification system.The effect of adding macromolecular monomer and polyoxyethylene segment length of the nonionic surfactant on emulsion copolymerization were analyzed.An optimized emulsifier system for FEVE is proposed,and the prepared FEVE latexes exhibit excellent storage stability and film formation ability.展开更多
Transcatheter arterial embolization(TAE)is the mainstay for treating advanced hepatocellular carcinoma(HCC),and the performance of the embolization material is crucial in TAE.With the development of medical imaging an...Transcatheter arterial embolization(TAE)is the mainstay for treating advanced hepatocellular carcinoma(HCC),and the performance of the embolization material is crucial in TAE.With the development of medical imaging and the birth of“X-ray-free”technologies,we designed a new dual-mode imaging material of dimethoxy tetraphenyl ethylene(DMTPE)via emulsification by mixing poly(N-isopropylacrylamide-co-acrylic acid)(PNA)with lipiodol and fluorocarbons,which was evaluated for temperature sensitivity,stability,and dual-mode visualization in vitro.Additionally,blood vessel casting embolization and renal artery imaging were assessed in healthy rabbits.In a rabbit model with a VX2 tumor,the effectiveness of TAE for treating HCC was examined,with an emphasis on evaluating long-term outcomes of embolization and its effects on tumor growth,necrosis,and proliferation through imaging techniques.In vitro experiments confirmed that the temperature-sensitive dual-oil-phase Pickering emulsion had good flow,stable contrast,and embolism when the oil-to-oil ratio and water-to-oil ratio were both 7:3(v/v)and stabilized with 8%PNA.Similarly,in vivo,arterial embolization confirmed the excellent properties of DMTPE prepared at the abovementioned ratios.It was observed that DMTPE not only has an antitumor effect but can also achieve dual imaging using X-rays and ultrasound,making it a promising excellent vascular embolization material for TAE in tumor treatment.展开更多
With oily wastewater treatment emerging as a critical global issue,porous media and shear forces have received significant attention as environmentally friendly methods for oil–water separation.This study systematica...With oily wastewater treatment emerging as a critical global issue,porous media and shear forces have received significant attention as environmentally friendly methods for oil–water separation.This study systematically simulates the dynamics of oil-in-water emulsion demulsification under porous media and shear forces using a color-gradient Lattice Boltzmann model.The morphological evolution and demulsification efficiency of emulsions are governed by porous media and shear forces.The effects of porosity and shear velocity on demulsification are quantitatively analyzed.(1)The presence of porous media enhances the ability of the flow field to trap oil droplets,with lower porosity corresponding to improved demulsification performance.Moreover,a more orderly arrangement of porous media promotes oil droplet coalescence.(2)Higher shear velocity in the flow field facilitates the aggregation of oil droplets.However,oscillatory shear conditions reduce the demulsification efficiency of emulsions.(3)Among the combined effects of shear velocity and porosity,porosity emerges as the dominant factor influencing emulsion demulsification.(4)Higher initial oil concentrations enhance demulsification efficiency.These simulation results provide valuable insights for further research on emulsion demulsification.展开更多
The stability of oil-dominated emulsions,including oil-based drilling fluids and crude oils,is crucial for mitigating gas hydrate risks in the petroleum and natural gas industries.Nanoparticles can stabilize oilwater ...The stability of oil-dominated emulsions,including oil-based drilling fluids and crude oils,is crucial for mitigating gas hydrate risks in the petroleum and natural gas industries.Nanoparticles can stabilize oilwater systems(Pickering emulsions)by residing at the oil-water interface.However,their effects on the kinetics of hydrate formation in these systems remain unclear.To address this,we experimentally investigated how hydrophilic and hydrophobic nano-CaCO_(3) influence CH4 hydrate formation within dynamic oil-water systems.A series of hydrate formation experiments were conducted with varying water cuts and different concentrations of nano-CaCO_(3) at a particle size of 20 nm,under 3℃ and 6 MPa.The induction time,hydrate formation volume,and hydrate growth rate were measured and calculated.The results indicate that hydrophilic nano-CaCO_(3) generally inhibits hydrate formation,particularly at high water cuts,while hydrophobic nano-CaCO_(3) can significantly inhibit or even prevent hydrate formation at low water cuts.Water cut strongly influences the kinetics of hydrate formation,and nanoparticle concentration also impacts the results,likely due to changes in oil-water interface stability caused by nanoparticle distribution.This study will offer valuable insights for designing deepwater oilbased drilling fluids using nanoparticles and ensuring safe multiphase flow in deepwater oil and gas operations.展开更多
Complex emulsions,such as double emulsions and high-internal-phase emulsions,have shown great applications in the fields of drug delivery,sensing,catalysis,oil-water separation and self-healing materials.Their control...Complex emulsions,such as double emulsions and high-internal-phase emulsions,have shown great applications in the fields of drug delivery,sensing,catalysis,oil-water separation and self-healing materials.Their controllable preparation is at the forefront of interface and material science.Surfactants and polymers have been widely used as emulsifiers for building complex emulsions.Yet some inherent disadvantages exist including multi-step emulsifications and low production efficiency.Alternatively,supramolecular polymer emulsifier for complex emulsions via one-step emulsification is rising as a new strategy due to the ease of preparation.In this feature article,we review our recent progresses in using supramolecular polymer emulsifiers for the preparation of complex emulsions.Double emulsions and high-internal-phase emulsions are successfully prepared via one-step emulsification with the help of different supramolecular interactions including electrostatic,hydrogen bond,coordination interaction and dynamic covalent bond,which will be particularly emphasized in detail.In the end,a comprehensive prospect is given for the future development of this field.This article is expected to provide new inspirations for preparing complex emulsions via supramolecular routes.展开更多
The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional...The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional fractions (saturates, aromatics, resins and asphaltenes) are also isolated from the heavy crude oil. These components have been characterized by spectroscopic methods (FT-IR), namely acid number, basic nitrogen number, ultimate analysis and molecular weight measurements using vapor pressure osmometry (VPO). The ion-exchange chromatography method based on separation by a functional group induces a little change on the nature of the crudes and reasonable mass balances can be easily obtained.展开更多
[Objective]Preservation and waterproof treatment are two crucial parts in wood protection, which can not only extend the service time, but also expand the application range of wood products. [Method] This work combine...[Objective]Preservation and waterproof treatment are two crucial parts in wood protection, which can not only extend the service time, but also expand the application range of wood products. [Method] This work combined CA with paraffin wax emulsion to treat wood samples, and basic properties of the compound system, such as stability （storage stability and centrifugal stability）, particle size and pH val-ue, and water repel ency （water absorption, shrinkage and swel ing） of treated sam-ples were investigated. [Result and Conclusion] 1） the compound systems of CA and paraffin latex had a favorable miscibility and stability; 2） compared with untreated wood, CA-treated samples showed poor water repel ing properties, whereas samples treated with the compound systems indicated an obvious reduction in water absorp-tion, and the shrinkage and swel ing of them were improved as wel .展开更多
A fluorine-containing polyacrylate copolymer emulsion was synthesized by a seed emulsion polymerization method, in which methyl methacrylate （MMA） and butyl acrylate （BA） were used as main monomers and hexafluorob...A fluorine-containing polyacrylate copolymer emulsion was synthesized by a seed emulsion polymerization method, in which methyl methacrylate （MMA） and butyl acrylate （BA） were used as main monomers and hexafluorobutyl methacrylate （HFMA） as fluorine-containing monomer. The structure and properties were characterized by Fourier transform infrared spectrum （FT-IR）, transmission electron microscopy （TEM）, particle size analysis, X-ray photoelectron spectroscopy （XPS）, contact angle （CA）, differential scanning calorimetry （DSC） and thermogravimetry （TG） analysis. The FTIR and TEM results showed that HFMA was effectively involved in the emulsion copolymerization, and the formed emulsion particles had a core-shell structure and a narrow particle size distribution. XPS and CA analysis revealed that a gradient concentration of fluorine existed in the depth profile of fluorine-containing emulsion film which was richer in fluorine and more hydrophobic in one side. DSC and TG analysis also showed that a clear core-shell structure existed in the fluorine-containing emulsion particles, and their film showed higher thermal stability than that of fluorine-free emulsion.展开更多
Using methyl methacrylate （MMA）, butyl acrylate（BA） and hexafluorobutyl acrylate（HFBA） as main raw materials, we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free em...Using methyl methacrylate （MMA）, butyl acrylate（BA） and hexafluorobutyl acrylate（HFBA） as main raw materials, we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free emulsion polymerization when the conception of particle design and polymer morphology was adopted. Moreover, the influence of mole ratio of BA to MAA, pH value on the oligomer was studied. And the effects of the added amount of oligomer, self-crosslinked monomer and HFBA, mass ratio of BA to MMA, reaction temperature and the initiator on the polymerization technology and the performance of the product, were investigated and optimized. The structure and performance of the fluorocarbon polymer emulsion were characterized and tested with FTIR, TEM, MFT and contact angle and water absorption of the latex film. The experimental results show that the optimal conditions for preparing fluorocarbon polymer emulsion are as follows： for preparing the oligomer, tool ratio of BA to MAA is equal to 1.0 ： 1.60, and pH value is controlled within the range of 8.0 and 9.0; for preparing fluorocarbon polymer emulsion, the added amount of oligmer[P（BA/MANa）] is 6%; mass ratio of BA to MMA is 40 ＂ 60; the added amount of self-crosslinked monomer is 2%, the added amount of HFBA is 15 %; reaction temperature is 80 ℃; the mixture of potassium persulfate and sodium bisulfite is used as the initiator. The film-forming stability of the fluorocarbon polymer emul- sion and the performance of the latex film, which is prepared with the soap-free emulsion polymerization, are better than that prepared with the conventional emulsion polymerization.展开更多
The structure and properties of functional nanoparticles are important for stabilizing Pickering emulsion polymerization.Recently,cellulose nanocrystals(CNCs)are increasingly favored as a bio-based stabilizer for Pick...The structure and properties of functional nanoparticles are important for stabilizing Pickering emulsion polymerization.Recently,cellulose nanocrystals(CNCs)are increasingly favored as a bio-based stabilizer for Pickering emulsions.In this study,we reported a novel functionalized polyphosphoester-grafted CNCs for the stabilization of oil-in-water Pickering emulsions and the emulsion polymerization of styrene.First,polyphosphoester containing an amino group at one end of the chain,abbreviated as PBYP-NH2,was prepared by ring-opening polymerization(ROP)and hydrolysis reaction,wherein PBYP represents poly[2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane].Subsequently,CNC-COOH was obtained via 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidation of CNCs.The functionalized nanocrystals CNC-PBYP-COOH with carboxyl groups and polyphosphoester on the surface were obtained by the amidation reaction of PBYP-NH2 with CNC-COOH.Finally,we used CNC-PBYP-COOH as sole particle emulsifiers to stabilize styrene-in-water Pickering emulsions and studied its effects on the emulsions in details by using dynamic light scattering(DLS).The results indicated that the properties of these emulsions depended on the concentration of hydrophobically modified CNCs,volume ratios of oil to water,and pH values.The modified CNCs had higher ability to stabilize the styrene-in-water emulsions relative to the unmodified CNCs,and a stable oil-in-water(o/w)Pickering emulsion with diameter of hundreds of nanometers could be obtained.The resulting emulsions could be polymerized to yield nanosized latexes.The polyphosphoester-modified CNCs as green particle emulsifiers can efficiently stabilize nanoemulsions and latexes,which would promote the development of novel environmentally friendly materials.展开更多
文摘Non-aqueous emulsions have a wide range of applications in cosmetics,drug-controlled release,and the preparation of functional nanoparticles.However,due to the weaker polarity of non-aqueous solvents,these emulsions often exhibit inferior stability compared to their aqueous counterparts.In this experiment,the properties of quaternary ammonium surfactants in glycerol were investigated through surface tension measurements,to further enhance the stability of n-decane/glycerol emulsions,hydrophilic nanoparticles SiO_(2) were modified in situ using double tailed quaternary ammonium surfactants Di-C_(12)DAB and Di-C_(16)DAB.Stable n-decane/glycerol Pickering emulsions were successfully prepared.These emulsions were stable at 45℃for over six months,and no significant changes in droplet size occurred.The minimum droplet size of the emulsion was only 2-3μm.Contact angle measurements showed that the wettability of the silica surface was tremendously affected by the concentration and the alkyl chain length of the double-tailed surfactants.In the presence of Di-C_(12)DAB,the contact angle of glycerol on the silica surface increased monotonically with the surfactant concentration.This explains the phenomenon that the Pickering emulsions containing Di-C_(12)DAB and silica particles were stable within the contact angle range of 80°-120°.Comparatively,the contact angle of the glycerol on the silica surface in the presence of Di-C_(16)DAB first increased with surfactant concentrations and then decreased,reaching a maximum at 0.6 mmol/L.It can be concluded that Di-C_(12)DAB formed monolayers at the surface of silica particles within all investigated concentrations.On the contrary,Di-C_(16)DAB formed monolayers at concentrations below 0.6 mmol/L and formed double layers at concentrations above 0.6 mmol/L,leading to a non-monotonic change in the contact angle with respect to concentration.Using these stable non-aqueous Pickering emulsions as templates,polymer microspheres with a particle size of 2-3μm were successfully prepared with high yield.This work is helpful to expand the potential applications of non-aqueous emulsions in the encapsulation of drug,controlled release,material preparation,and cosmetic formulations.
文摘The stability of acid-crude oil emulsion poses manifold issues in the oil industry.Experimentally evaluating this phenomenon may be costly and time-consuming.In contrast,machine learning models have proven effective in predicting and evaluating various phenomena.This research is the first of its kind to assess the stability of acid-crude oil emulsion,employing various classification machine learning models.For this purpose,a data set consisting of 249 experimental data points belonging to 11 different crude oil samples was collected.Three tree-based models,namely decision tree(DT),random forest(RF),and categorical boosting(CatBoost),as well as three artificial neural network models,namely radial basis function(RBF),multi-layer perceptron(MLP) and convolutional neural network(CNN),were developed based on the properties of crude oil,acid,and protective additive.The CatBoost model obtained the highest accuracy with 0.9687,followed closely by the CNN model with 0.9673.In addition,confusion matrix findings showed the superiority of the CatBoost model.Finally,by applying the SHapley Additive exPlanations(SHAP) method to analyze the impact of input parameters,it was found that the crude oil viscosity has the most significant effect on the model's output with the mean absolute SHAP value of 0.88.
基金supported by the Natural Science Foundation of Shandong Province(ZR2021ME007)the National Natural Science Foundation in China(51574267)the Key Projects of China National Key Research and Development Plan(2019YFA0708703)。
文摘During oil displacement,surfactants often encounter challenges such as emulsion instability and channeling,which can compromise their efficiency.To address these issues,polymer microspheres were synthesized via reverse microemulsion polymerization using acrylamide,2-methyl-2-acrylamidopropane sulfonic acid,and stearyl methacrylate as monomers,with N,N-methylenebisacrylamide as the crosslinker.The microspheres were then combined with sodium alkyl alcohol polyoxyethylene ether carboxylate to enhance emulsion stability and expand the swept volume of surfactant.A stable reverse microemulsion system was prepared using the maximum water solubilization rate as the indicator,and microspheres were synthesized based on this system.The ability of the microspheres to enhance emulsion stability was systematically evaluated.The plugging performance and enhanced oil recovery(EOR)efficiency of the microsphere/surfactant composite system were assessed through core seepage and oil displacement experiments.The experimental results demonstrated that microspheres were successfully prepared in a water-in-oil reverse microemulsion system with a solubilization rate of 42%.The emulsion stability was evaluated under an oil-to-water ratio of 7:3,a temperature of 80℃,and a salinity of 44,592 mg/L,by manually shaking the test tube five times.It was observed that the complete phase separation time of the emulsion increased from 10 to 120 min after the addition of microspheres.Under different permeability conditions(100×10^(-3),300×10^(-3),500×10^(-3)μm^(2)),the recovery efficiency of the composite system increased by 4.5%,8.3%,and 4.8%,respectively,compared to a single surfactant system.The microspheres developed in this study enhanced emulsion stability and increased the swept volume of surfactant within the formation,significantly boosting its oil recovery efficiency.
基金Funded by a Science and Technology Project from the Ministry of Housing and Urban-Rural Development of the People’s Republic of China(No.2019-K-047)Yangzhou Government-Yangzhou University Cooperative Platform Project for Science and Technology Innovation(No.YZ2020262)。
文摘The chloride penetration resistance of cement-based grout materials was improved by nano-silica emulsion.Specimens of mixtures containing different nano-silica particles or emulsions were exposed in sodium chloride solutions of specific concentrations with different test ages.Hardened properties of the mixes were assessed in terms of weight loss and compressive strength.X-ray diffraction(XRD)and scanning electron microscopy(SEM)of mixes were performed to analysis the phase evolution and microstructure.The results demonstrated that the introduction of nano-SiO_(2) emulsion significantly decreased the compressive strength loss and calcium hydroxide(CH)crystal content of hydration production,and then enhanced the resistance of cement-based grouting materials to chloride ion penetration.This improvement derives from the filling and pozzolanic effects of nano-SiO_(2) particles,which were incorporated via an emulsion and attributed to a well dispersion in grouting matrix.
文摘Naturally degradable capsule provides a platform for sustained fragrance release.However,practical challenges such as low encapsulation efficiency and difficulty in sustained release are still limited in using fragranceloaded capsules.In this work,the natural materials sodium alginate and gelatine are dissolved and act as the aqueous phase,lavender is dissolved in caprylic/capric triglyceride(GTCC)as the oil phase,and SiO_(2) nanoparticles with neutralwettability as a solid emulsifier to form O/W Pickering emulsions simultaneously.Finally,multi-core capsules are prepared using the drop injection method with emulsions as templates.The results show that the capsules have been successfully prepared with a spherical morphology and multi-core structure,and the encapsulation rate of multi-core capsules can reach up to 99.6%.In addition,the multi-core capsules possess desirable sustained release performance,the cumulative sustained release rate of fragrance at 25℃over 49 days is only 32.5%.It is attributed to the significant protection of multi-core structure,Pickering emulsion nanoparticle membranes,and hydrogel network shell for encapsulated fragrance.This study is designed to deliver a new strategy for using sustained-release technology with fragrance in food,cosmetics,textiles,and other fields.
基金supported by National Natural Science Foundation of China(32202235)。
文摘As a natural oil-soluble emulsifier to replace Polyglycerol Polyricinoleate(PGPR),lecithin's application in double emulsions(DEs)remains constrained due to low encapsulation efficiency and stability,while incorporating Pickering particles within the inner aqueous phase(W_(1))has emerged as an effective approach to enhance DEs stability.However,the interfacial interactions between Pickering particles in W_(1) and lecithin in oil phase and their effects on the physical,delivery and digestion properties of DEs remain to be explored.In this study,a natural Pickering DEs encapsulating blueberry anthocyanins(ANCs)was developed using lecithin and gliadinbased particles,with gliadin colloid particles(GCPs)introduced into W_(1).The effects of GCP concentration in W_(1) on emulsion droplet size,microstructure,W_(1)/O interfacial rheology,in vitro digestion,and ANCs delivery performance were systematically investigated.Results showed that GCPs in W_(1) accelerated the decreasing of W_(1)/O interfacial tension,indicating that,beyond competitive adsorption,combination between the two might also occur at the interface,which could accelerate the interfacial adsorption of lecithin.GCPs significantly improved the strength of the W_(1)/O interface,thus improving ANCs encapsulation efficiency from 49.66%to 70.60%.Moreover,the droplet size of DEs decreased from 38.94μm to 24.09μm as GCPs concentration increased,indicating that some GCPs might transfer to the outer aqueous phase through phase exchange,acting as hydrophilic emulsifiers.GCPs in W_(1) can modulate ANCs in vitro release,enhancing ANCs'bioaccessibility(31.10%)and antioxidant capacity.
文摘Poly(octamethylene citrate)(POC)is a promising bioelastomer material in the biomedical field.However,its thermosetting nature poses a significant challenge to processing and molding,especially manufacturing the POC-based elastomer particles as potential,degradable and toughened fillers.Firstly,a Pickering emulsion with a pre-polymer(pre-POC)solution in dimethyl carbonate as a dispersed oil phase,a Pullulan(PUL)aqueous solution as a continuous water phase,and chitin nanocrystal(ChiNC)as a particle-type emulsifier was constructed.Secondly,the POC-based core/shell structured microspheres were prepared by spray-drying of the emulsions,and characterized by a scanning electron microscope and a transmission electron microscope.Finally,the POC-based core/shell structured microspheres were used as elastomer fillers to strengthen and toughen a chitosan film,resulting in 26%increase in the tensile strength and 45%increase in the strain at break;the POC-based core/shell structured microsphere as a double-layer drug release system was built in which the hydrophilic drug of tetracycline hydrochloride(TCH)was released from the outer layer and the hydrophobic drug of curcumin was released from the inner layer,roughly following the Ritger-Peppas model.
基金support from the National Natural Science Foundation of China(Nos.51922020,52273064 and 52221006)the Fundamental Research Funds for the Central Universities(BHYC1707B)is gratefully acknowledged.
文摘Flexible and conformable nanomaterial-based functional hydrogels find promising applications in various fields.However,the controllable manipulation of functional electron/mass transport networks in hydrogels remains rather challenging to realize.We describe a general and versatile surfactant-free emulsion construction strategy to customize robust functional hydrogels with programmable hierarchical structures.Significantly,the amphipathy of silk fibroin(SF)and the reinforcement effect of MXene nanosheets produce sable Pickering emulsion without any surfactant.The followed microphase separation and self-cross-linking of the SF chains induced by the solvent exchange convert the composite emulsions into high-performance hydrogels with tunable microstructures and functionalities.As a proof-of-concept,the controllable regulation of the ordered conductive network and the water polarization effect confer the hydrogels with an intriguing electromagnetic interference shielding efficiency(~64 dB).Also,the microstructures of functional hydrogels are modulated to promote mass/heat transfer properties.The amino acids of SF and the surface terminations of MXene help reduce the enthalpy of water evaporation and the hierarchical structures of the hydrogels accelerate evaporation process,expecting far superior evaporation performance(~3.5 kg m^(-2)h^(-1))and salt tolerance capability compared to other hydrogel evaporators.Our findings open a wealth of opportunities for producing functional hydrogel devices with integrated structure-dependent properties.
文摘Stable HCl-crude oil emulsion and its subsequent sludge formation,with detrimental impacts on oil production,may stem from acid stimulation.One major ambiguity in this process is to discern the most influential component of crude oil on the stability of formed emulsions.This fundamental question has not adequately been addressed in previous studies.In this work,the impact of de-asphalted part of crude oil(maltene)has been investigated on the acid-induced emulsion and sludge separately.Accordingly,the emulsion phase separation and the amount of formed sludge have been compared for four crude oils and their maltene samples for different concentrations of ferric ion and acidic pH values.The results of phase separation,as a criterion for emulsion stability,showed that crude oil samples formed 6 to 25 percent more stable emulsions than maltene samples,when using blank HCl.The emulsions of maltene and spent acid(pH=2)broke completely during the first 15 min after emulsification.In addition,the maltene components usually had less contribution to sludge formation in the presence of blank HCl.It was concluded that asphaltene is the key component during interaction with HCl.However,the maltene of one crude sample formed higher acid sludge in comparison to its crude oil.For acid solutions containing 3000 ppm of ferric ion,the emulsion stability increased for all crude oil and maltene samples.Moreover,the stability of some maltene emulsions increased to 48%and 100%in the presence of 3000 ppm of ferric ions.The presence of ferric ions caused forming very stable emulsions,while most of the sludge formation took place at higher pH values.Finally,it was also attained that emulsion and sludge formations could happen simultaneously.
文摘This study prepared and characterized amphiphilic carboxymethyl cellulose stearate(CMCS)recycled from sugarcane bagasse agro-waste(SB).The Fourier-transform infrared(FTIR)analysis confirmed cellulose,carboxymethyl cellulose(CMC),and CMCS structures,with CMCS showing increased H-bonding.X-ray diffraction analysis(XRD)revealed reduced crystallinity in CMC and CMCS.CMCS exhibited a hydrophobic nature but dispersed in water,enabling nanoemulsion formation.Optimal nanoemulsion was achieved with CMCS1,showing a particle size of 99 nm.Transmission electron microscopy(TEM)images revealed CMC’s honeycomb structure,transforming into spherical particles in CMCS1.Antimicrobial tests demonstrated strong activity of CMCS formulations against Escherichia coli and Staphylococcus aureus,with CMCS3 exhibiting the highest efficacy.These findings highlight the potential of CMCS-based nanoemulsions for antimicrobial applications and nanoemulsification.
基金financially supported by the joint lab of Shanghai Huayi 3F New Materials Co.,Ltd.Donghua University。
文摘Copolymers of fluoroethylene and vinyl ethers(FEVE)are soluble and curable at relatively low temperature,and are used as high-performance coatings and paints.Currently,most market-available FEVE products obtained through solution polymerization contain a large fraction of organic solvent,and hence,volatile organic compound(VOC)emissions cause environmental issues.In this study,the emulsion copolymerization of chlorotrifluoroethylene(CTFE)and vinyl ethers using an environmentally friendly emulsification system to produce waterborne FEVE was investigated.In addition to mixed nonionic and ionic surfactants,macromolecular monomer with double bond and polyoxyethylene segments were used in the emulsification system.The effect of adding macromolecular monomer and polyoxyethylene segment length of the nonionic surfactant on emulsion copolymerization were analyzed.An optimized emulsifier system for FEVE is proposed,and the prepared FEVE latexes exhibit excellent storage stability and film formation ability.
基金supported by the Hubei Province Nature Science Foundation of China(Grant No.:2023AFB1077)the National Natural Science Foundation of China(Grant No.:82003308)+2 种基金the Doctoral Start-up Fund Project of Hubei University of Science and Technology,China(Grant No.:BK202118)the Innovation team and Medical research program of Hubei University of Science and Technology,China(Grant Nos.:2023T10 and 2022YKY05)the Hubei Province Key R&D Plan Big Health Local Special Project,China(Grant No.:2022BCE042).
文摘Transcatheter arterial embolization(TAE)is the mainstay for treating advanced hepatocellular carcinoma(HCC),and the performance of the embolization material is crucial in TAE.With the development of medical imaging and the birth of“X-ray-free”technologies,we designed a new dual-mode imaging material of dimethoxy tetraphenyl ethylene(DMTPE)via emulsification by mixing poly(N-isopropylacrylamide-co-acrylic acid)(PNA)with lipiodol and fluorocarbons,which was evaluated for temperature sensitivity,stability,and dual-mode visualization in vitro.Additionally,blood vessel casting embolization and renal artery imaging were assessed in healthy rabbits.In a rabbit model with a VX2 tumor,the effectiveness of TAE for treating HCC was examined,with an emphasis on evaluating long-term outcomes of embolization and its effects on tumor growth,necrosis,and proliferation through imaging techniques.In vitro experiments confirmed that the temperature-sensitive dual-oil-phase Pickering emulsion had good flow,stable contrast,and embolism when the oil-to-oil ratio and water-to-oil ratio were both 7:3(v/v)and stabilized with 8%PNA.Similarly,in vivo,arterial embolization confirmed the excellent properties of DMTPE prepared at the abovementioned ratios.It was observed that DMTPE not only has an antitumor effect but can also achieve dual imaging using X-rays and ultrasound,making it a promising excellent vascular embolization material for TAE in tumor treatment.
基金funded by the National Natural Science Foundation of China,grant number:12161058Heping Wang is the recipient of this funding.This research was funded by the National Natural Science Foundation of China,grant number:12361096+1 种基金Heping Wang is the recipient of this funding.This research was also funded by the Science and Technology Plan Project of Qinghai Province-Applied Basic Research Plan,grant number:2023-ZJ-736Yanggui Li is the recipient of this funding.
文摘With oily wastewater treatment emerging as a critical global issue,porous media and shear forces have received significant attention as environmentally friendly methods for oil–water separation.This study systematically simulates the dynamics of oil-in-water emulsion demulsification under porous media and shear forces using a color-gradient Lattice Boltzmann model.The morphological evolution and demulsification efficiency of emulsions are governed by porous media and shear forces.The effects of porosity and shear velocity on demulsification are quantitatively analyzed.(1)The presence of porous media enhances the ability of the flow field to trap oil droplets,with lower porosity corresponding to improved demulsification performance.Moreover,a more orderly arrangement of porous media promotes oil droplet coalescence.(2)Higher shear velocity in the flow field facilitates the aggregation of oil droplets.However,oscillatory shear conditions reduce the demulsification efficiency of emulsions.(3)Among the combined effects of shear velocity and porosity,porosity emerges as the dominant factor influencing emulsion demulsification.(4)Higher initial oil concentrations enhance demulsification efficiency.These simulation results provide valuable insights for further research on emulsion demulsification.
基金supported by the National Natural Science Foundation of China(No.42402319,51704266)the Anhui Provincial Natural Science Foundation(No.2308085QE151)+3 种基金the Natural Science Research Project of Anhui Educational Committee(No.2023AH051222)Young Talent Nurturing Program of Anhui Association For Science and Technology(No.RCTJ202403)the Open Foundation of the Innovation Base of Fine Mine Prospecting and Intelligent Monitoring Technology(No.2023-MPIM-01)partly supported by the Open Fund of Engineering Research Center of Rock-Soil Drilling&Excavation and Protection(No.202407).
文摘The stability of oil-dominated emulsions,including oil-based drilling fluids and crude oils,is crucial for mitigating gas hydrate risks in the petroleum and natural gas industries.Nanoparticles can stabilize oilwater systems(Pickering emulsions)by residing at the oil-water interface.However,their effects on the kinetics of hydrate formation in these systems remain unclear.To address this,we experimentally investigated how hydrophilic and hydrophobic nano-CaCO_(3) influence CH4 hydrate formation within dynamic oil-water systems.A series of hydrate formation experiments were conducted with varying water cuts and different concentrations of nano-CaCO_(3) at a particle size of 20 nm,under 3℃ and 6 MPa.The induction time,hydrate formation volume,and hydrate growth rate were measured and calculated.The results indicate that hydrophilic nano-CaCO_(3) generally inhibits hydrate formation,particularly at high water cuts,while hydrophobic nano-CaCO_(3) can significantly inhibit or even prevent hydrate formation at low water cuts.Water cut strongly influences the kinetics of hydrate formation,and nanoparticle concentration also impacts the results,likely due to changes in oil-water interface stability caused by nanoparticle distribution.This study will offer valuable insights for designing deepwater oilbased drilling fluids using nanoparticles and ensuring safe multiphase flow in deepwater oil and gas operations.
基金financially supported by the National Natural Science Foundation of China(Nos.21674127,21422407 and 51373197)
文摘Complex emulsions,such as double emulsions and high-internal-phase emulsions,have shown great applications in the fields of drug delivery,sensing,catalysis,oil-water separation and self-healing materials.Their controllable preparation is at the forefront of interface and material science.Surfactants and polymers have been widely used as emulsifiers for building complex emulsions.Yet some inherent disadvantages exist including multi-step emulsifications and low production efficiency.Alternatively,supramolecular polymer emulsifier for complex emulsions via one-step emulsification is rising as a new strategy due to the ease of preparation.In this feature article,we review our recent progresses in using supramolecular polymer emulsifiers for the preparation of complex emulsions.Double emulsions and high-internal-phase emulsions are successfully prepared via one-step emulsification with the help of different supramolecular interactions including electrostatic,hydrogen bond,coordination interaction and dynamic covalent bond,which will be particularly emphasized in detail.In the end,a comprehensive prospect is given for the future development of this field.This article is expected to provide new inspirations for preparing complex emulsions via supramolecular routes.
文摘The functional fractions (acid, basic, amphoteric and neutral fractions) are isolated from the Liaohe Du-84 heavy crude oil and Shengli Gudao Kenxi heavy crude oil by ion-exchange chromatography, but the conventional fractions (saturates, aromatics, resins and asphaltenes) are also isolated from the heavy crude oil. These components have been characterized by spectroscopic methods (FT-IR), namely acid number, basic nitrogen number, ultimate analysis and molecular weight measurements using vapor pressure osmometry (VPO). The ion-exchange chromatography method based on separation by a functional group induces a little change on the nature of the crudes and reasonable mass balances can be easily obtained.
基金Supported by Beijing Municipal Student Research Training Program in Beijing ForestryUniversity(S201310022020)Fundamental Research Funds for the Central Universities(TD2011-14)~~
文摘[Objective]Preservation and waterproof treatment are two crucial parts in wood protection, which can not only extend the service time, but also expand the application range of wood products. [Method] This work combined CA with paraffin wax emulsion to treat wood samples, and basic properties of the compound system, such as stability （storage stability and centrifugal stability）, particle size and pH val-ue, and water repel ency （water absorption, shrinkage and swel ing） of treated sam-ples were investigated. [Result and Conclusion] 1） the compound systems of CA and paraffin latex had a favorable miscibility and stability; 2） compared with untreated wood, CA-treated samples showed poor water repel ing properties, whereas samples treated with the compound systems indicated an obvious reduction in water absorp-tion, and the shrinkage and swel ing of them were improved as wel .
基金Supported by the National Natural Science Foundation of China （20476035, 20846003）.
文摘A fluorine-containing polyacrylate copolymer emulsion was synthesized by a seed emulsion polymerization method, in which methyl methacrylate （MMA） and butyl acrylate （BA） were used as main monomers and hexafluorobutyl methacrylate （HFMA） as fluorine-containing monomer. The structure and properties were characterized by Fourier transform infrared spectrum （FT-IR）, transmission electron microscopy （TEM）, particle size analysis, X-ray photoelectron spectroscopy （XPS）, contact angle （CA）, differential scanning calorimetry （DSC） and thermogravimetry （TG） analysis. The FTIR and TEM results showed that HFMA was effectively involved in the emulsion copolymerization, and the formed emulsion particles had a core-shell structure and a narrow particle size distribution. XPS and CA analysis revealed that a gradient concentration of fluorine existed in the depth profile of fluorine-containing emulsion film which was richer in fluorine and more hydrophobic in one side. DSC and TG analysis also showed that a clear core-shell structure existed in the fluorine-containing emulsion particles, and their film showed higher thermal stability than that of fluorine-free emulsion.
基金Funded by the Jiangsu Provincial Creative Fund for Scientific and Tech-nical Small and Medium-size Enterprise
文摘Using methyl methacrylate （MMA）, butyl acrylate（BA） and hexafluorobutyl acrylate（HFBA） as main raw materials, we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free emulsion polymerization when the conception of particle design and polymer morphology was adopted. Moreover, the influence of mole ratio of BA to MAA, pH value on the oligomer was studied. And the effects of the added amount of oligomer, self-crosslinked monomer and HFBA, mass ratio of BA to MMA, reaction temperature and the initiator on the polymerization technology and the performance of the product, were investigated and optimized. The structure and performance of the fluorocarbon polymer emulsion were characterized and tested with FTIR, TEM, MFT and contact angle and water absorption of the latex film. The experimental results show that the optimal conditions for preparing fluorocarbon polymer emulsion are as follows： for preparing the oligomer, tool ratio of BA to MAA is equal to 1.0 ： 1.60, and pH value is controlled within the range of 8.0 and 9.0; for preparing fluorocarbon polymer emulsion, the added amount of oligmer[P（BA/MANa）] is 6%; mass ratio of BA to MMA is 40 ＂ 60; the added amount of self-crosslinked monomer is 2%, the added amount of HFBA is 15 %; reaction temperature is 80 ℃; the mixture of potassium persulfate and sodium bisulfite is used as the initiator. The film-forming stability of the fluorocarbon polymer emul- sion and the performance of the latex film, which is prepared with the soap-free emulsion polymerization, are better than that prepared with the conventional emulsion polymerization.
基金the National Natural Science Foundation of China(Nos.21975169 and 21374066)the Major Program of the Natural Science Project of Jiangsu Higher Education Institutions(No.15KJA150007)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20171212)a Project Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education InstitutionsSoochow-Waterloo University Joint Project for Nanotechnology from Suzhou Industrial Park.
文摘The structure and properties of functional nanoparticles are important for stabilizing Pickering emulsion polymerization.Recently,cellulose nanocrystals(CNCs)are increasingly favored as a bio-based stabilizer for Pickering emulsions.In this study,we reported a novel functionalized polyphosphoester-grafted CNCs for the stabilization of oil-in-water Pickering emulsions and the emulsion polymerization of styrene.First,polyphosphoester containing an amino group at one end of the chain,abbreviated as PBYP-NH2,was prepared by ring-opening polymerization(ROP)and hydrolysis reaction,wherein PBYP represents poly[2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane].Subsequently,CNC-COOH was obtained via 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidation of CNCs.The functionalized nanocrystals CNC-PBYP-COOH with carboxyl groups and polyphosphoester on the surface were obtained by the amidation reaction of PBYP-NH2 with CNC-COOH.Finally,we used CNC-PBYP-COOH as sole particle emulsifiers to stabilize styrene-in-water Pickering emulsions and studied its effects on the emulsions in details by using dynamic light scattering(DLS).The results indicated that the properties of these emulsions depended on the concentration of hydrophobically modified CNCs,volume ratios of oil to water,and pH values.The modified CNCs had higher ability to stabilize the styrene-in-water emulsions relative to the unmodified CNCs,and a stable oil-in-water(o/w)Pickering emulsion with diameter of hundreds of nanometers could be obtained.The resulting emulsions could be polymerized to yield nanosized latexes.The polyphosphoester-modified CNCs as green particle emulsifiers can efficiently stabilize nanoemulsions and latexes,which would promote the development of novel environmentally friendly materials.
