Journal of Materials Chemistry A
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2013
·Vol. 1
·期 17
·5353-5360
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IF 0
Chunfeng Ma,Xiaobo Bi,To Ngai,Guangzhao Zhang
Well-defined polyurethane (PU)-based grafted copolymers with poly(2-(dimethylamino)ethyl methacrylate) (PDEM) side chains were prepared by a combination of radical polymerization and condensation reaction. They can self-assemble in water to form nanoparticles with PU as the core and hydrophilic PDEM chains as the shell. Tuning the pH value of the solutions allowed these nanoparticles to stabilize either oil-in-water (O/W) or water-in-oil (W/O) Pickering emulsions. Stable O/W emulsions were obtained with PU-based nanoparticles in the pH 3–5 or pH 11–12 range due to their better affinity to the aqueous phase. In contrast, changing the pH value to the range of 8–9 significantly changed the stabilizing behavior of the nanoparticles, leading to the formation of stable W/O emulsions. Additionally, the effect of oil polarity on the emulsification behavior of the PU-based nanoparticles was investigated. For highly non-polar oil like n-hexane, only O/W emulsions were generated and the resulting emulsions showed no response to pH change.
研究领域:
材料科学
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化学工程
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DOI
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2023
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IF 2.2
Kun Li,Xiaoxiao Li,Anqi Ming,Yiming Guo,Jun Sun,Hua Wang,Jianjun Ding,Xingyou Tian,Yuxiang Cao,Yuwei Lin
The properties of Pickering emulsions is affected by many factors, one of the most typical of which is the ionic environment. Existing studies have mainly focused on the effect of ions in the continuous phase on oil-in-water Pickering emulsions, and usually only single species of ions are studied. The water-in-oil Pickering emulsions are commonly used to encapsulate a variety of water-soluble functional substances, which often contain various of ions. Therefore, it is necessary to study the effect of ions in the internal phase on the properties of inverse Pickering emulsions. The inverse Pickering emulsions with an average droplet size of 100 μm were prepared using hydrophobized calcium carbonate particles. Subsequently, Na+ and Ca2+ were introduced into the internal phase to investigate their effects on the emulsion. The results show that the presence of Na+ can aggravate droplet coalescence, and Ca2+ can cause severe damage to the emulsions and even lead to phase inversion. It was speculated that Na+ can weaken the surface charge of particles by compressing the electric double layer, resulting in lower electrostatic repulsion between particles, thus changing the dispersion state of the particles and ultimately affecting the properties of the emulsion. And Ca2+ can combine with and release stearate from the particle surface through chemical reactions, thus changing the wettability of the particles and resulting in breaking and phase inversion of the emulsions. The present work is informative for the setting of the phase composition and the prediction of stability during the application of inverse Pickering emulsions.
研究领域:
化学
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材料科学
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食品科学
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Tengfang Zhang,Ziqi Wu,Huafeng Zhu,Zhikun Wang,Shuangqing Sun,Songqing Hu
Hypothesis Natural polymer chitosan (CS) has been widely used as emulsifier due to its good stability, salt-resistant, and stimuli-responsive demulsification . However, chitosan is a hydrocarbon structure molecule containing -NH 3+ and -OH with low surface activity, which is mainly suitable for some specific oil-water systems such as corn oil and sunflower oil . Appropriate hydrophilic-hydrophobic modification of chitosan by PNIPAM not only increases its surface activity but also introduces a temperature response on chitosan. Experiments Pickering emulsions (O/W) formed by CS-PNIPAM were prepared. The stability and response performance of the emulsions were investigated by observing the macroscopic states, microscopic images, droplet size distributions, emulsion emulsification indices, water partition rates, etc. Molecular dynamics and dissipative particle dynamics simulations were used to reveal the distribution pattern of the emulsifiers at the water-oil interface and clarify the stabilization and pH/temperature response mechanism of the emulsions. Findings CS-PNIPAM performs excellent emulsification in various oil phases. The addition of salt ions enhances the stability performance of the emulsion. At low pH, CS will be protonated to break the emulsion, while increasing the pH will deprotonate CS and reform the emulsion. Also, the increase of temperature to 80 °C leads to emulsion breakage due to the agglomeration of PNIPAM.
研究领域:
化学工程
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材料科学
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食品科学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
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2023
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IF 11.2
Shuntian Huang,Zhaojun Wang,Qichang Zhou,Shujuan Yang,Riting Huang,Keyang Mai,Wenqi Qin,Junhao Huang,Gaobo Yu,Yuhong Feng,Jiacheng Li
Polysaccharide-based soft colloidal particles mediated by the dynamic bonding-engineered interfacial self-assembly can regulate the properties of oil-water interfacial films, availing the stability of emulsions under a wide pH range. The amphiphilic phenylboronic alginate soft colloidal particles (Alg-PBA) were designed to stabilize pH-responsive Pickering emulsions (PEs). Combining stability analysis with quartz crystal microbalance and dissipation monitoring (QCM-D), the microstructure and viscoelasticity of Alg-PBA at the oil-water interface were determined. The results showed that PEs stabilized by Alg-PBA due to a thicker and stronger viscoelastic interface film induced by B O bonds and hydrogen bonds . The structure-function relationship of the Alg-PBA emulsifier driven by dynamic bonds was further elaborated at multiple scales by laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Meanwhile, the microstructure of aerogels templated by emulsion could be tuned by adjusting dynamic bonds, which provides a new idea for polysaccharide soft material engineering.
研究领域:
食品科学
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材料科学
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DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 15
·2587
·
IF 5.719
Gaihuan Ren,Zhanzhao Li,Dongxu Lu,Bo Li,Lulu Ren,Wenwen Di,Hongqin Yu,Jianxin He,Dejun Sun
Herein, we describe pH and magnetism dual-responsive liquid paraffin-in-water Pickering emulsion stabilized by dynamic covalent Fe3O4(DC-Fe3O4) nanoparticles. On one hand, the Pickerinfigureg emulsions are sensitive to pH variations, and efficient demulsification can be achieved by regulating the pH between 10 and 2 within 30 min. The dynamic imine bond in DC-Fe3O4can be reversibly formed and decomposed, resulting in a pH-controlled amphiphilicity. The Pickering emulsion can be reversibly switched between stable and unstable states by pH at least three times. On the other hand, the magnetic Fe3O4core of DC-Fe3O4allowed rapid separation of the oil droplets from Pickering emulsions under an external magnetic field within 40 s, which was a good extraction system for purifying the aqueous solution contaminated by rhodamine B. The dual responsiveness enables Pickering emulsions to have better control of their stability and to be applied more broadly.
研究领域:
材料科学
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化学工程
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环境科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
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IF 8.5
Lihua Zhang,Yuli Ning,Yinjiao Wei,Yingying Xin,Bakht Ramin Shah,Hongtao Du,Jian Zou,Wei Xu
Konjac glucomannan (KGM) undergoes deacetylation in alkaline conditions, while κ-carrageenan (CRG) is sensitive to potassium ions. This study examines the influence of K 2 CO 3 on the mechanical properties of KGM/CRG-based camellia oil Pickering emulsion gels. Texture analysis and rheological testing revealed that the addition of K 2 CO 3 significantly enhanced the mechanical properties of emulsion gels. Texture parameters, such as the hardness, gumminess, and chewiness of the gel, were closer to those of pork back fat when the K 2 CO 3 concentration was 0.2 M. The addition of K 2 CO 3 enhance the intermolecular crosslinking within the gel and formed a more uniform and dense gel network, promoting gelation and structural stability, which were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and microstructural analysis. Besides, low-field nuclear magnetic resonance and thermogravimetric analyses indicated that the addition of K 2 CO 3 reduced the water mobility of the gel and improved its thermal stability. Physicochemical and color analysis results showed that the energy value of the camellia oil Pickering emulsion gel was only 15.9 % that of pork back fat, and its appearance was closer to that of pork back fat than hydrogels. This study provides technical support for the use of KGM/CRG-based camellia oil Pickering emulsion gels as fat analogs.
研究领域:
食品科学
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生物化学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2025
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IF 5.4
Han Bao,Xianhai Liu,Chunhui Li,Jinfeng Dong,Xuefeng Li
Rod-coil copolymer amphiphiles show interesting self-assembly behaviors and promising application potential, whereas the development of them with controllable amphiphilicity is still challenge. Alternatively, rod-coil copolymer homologues with diversified compositions can be generated conveniently by the dynamic covalent imine approach through altering the molecular structures of amino precursors (A) and aldehyde precursors (D m ). In this work, a family of dynamic covalent imine rod-coil copolymers (D m -A) were generated in water in situ at the constant -NH 2 /-CHO molar ratio of 1 by employing phenyl, biphenyl, terphenyl and tetraphenylethylene based aromatic amines as A and block copolymer poly( N -(2-methacryloylxy) ethyl pyrrolidone)- b -poly(4-(formaldehyde) phenyl methacrylate) (PNMP 72 - b -PBFMA m , m = 3, 13 and 24) as D m , respectively. Moreover, the molecular effects of different precursors on the self-assembly and emulsification behaviors of rod-coil copolymers D m -As were studied systematically. Spherical micelles are the preferred morphologies nearly for all the generated D m -As, except the one generated by D 24 and 4-amino- p -terphenyl (TPA). Alternatively, long and entangled wormlike micelles become favorable attributing to the strong hydrophobic interactions. All D m -A micelles show excellent emulsification in the dodecane/water systems and favor the formation of O/W emulsions as revealed by the confocal laser scanning microscopy (CLSM) method. The interfacial compositions of emulsions are mainly determined by D m but slightly by A. In comparison D 13 -As and D 24 -As micelles with D 3 -As micellar emulsifiers with the same A, the former ones commonly favor the formation of structurally well-defined Pickering emulsions with relatively larger sizes and high fluorescent contrasts between the interfacial layers and dispersed oil droplets. This is because D m -As with the larger m not only have the longer hydrophobic tails but also combine more precursors A as the hydrophobic parts. Both factors enhance the hydrophobic interactions within micelles, endowing D m -A micelles with better anti-shear stability to favor the formation of Pickering emulsions.
研究领域:
材料科学
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化学工程
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界面科学
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DOI
高影响因子
LANGMUIR
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2024
·
IF 3.7
Zhuoxue Li,Yunlei Shi,Yimian Ding,Dazhen Xiong,Zhiyong Li,Huiyong Wang,Jikuan Qiu,Xiaopeng Xuan,Jianji Wang
A Pickering emulsion is a natural microreactor for interfacial catalysis in which an emulsifier is critical. Recently, a metal–organic framework (MOF) has attracted attention to emulsify water–organic mixtures for constructing a Pickering emulsion. However, a few stimuli-responsive Pickering emulsions based on MOFs have been reported, and the MOF emulsifiers cannot be regenerated at room temperature. Herein, the Zr-MOF with a rodlike morphology is synthesized using ionic liquid as a modulator and then modified with n-(trimethoxysilylpropyl)imidazole (C3im) to prepare a series of functionalized Zr-MOFs (MOF-C3im). It is found that MOF-C3im is an excellent emulsifier to construct stable and CO2-responsive Pickering emulsions even at low content (>0.20 wt %). Notably, the emulsification and demulsification of the emulsions can be easily and reversibly switched by bubbling of CO2 and N2 alternatively at room temperature because CO2 and imidazole molecules anchored on the Zr-MOF underwent a reversible acid–base reaction, resulting in an obvious change in the wettability of the emulsifier. As a proof of concept, the reduction reactions of nitrobenzene have been successfully carried out in these Pickering emulsions, demonstrating the efficient integration as a microreactor for chemical reaction, product separation, and emulsifier recycling under ambient conditions. This strategy provides an innovative option to develop stimulus-responsive Pickering emulsions for sustainable chemical processes.
研究领域:
材料科学
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化学工程
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催化反应
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产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Junjie Fan,Jianpeng Cui,Tianhao Zhang,Jianwen Hu,Ziqi Wu,Mingshuo Chi,Wenqing Xie,Shuangqing Sun,Songqing Hu
In this study, we successfully synthesized silica coated Fe 3 O 4 nanoparticles (Fe 3 O 4 @SiO 2 NPs) and further animated their surface to create amino modified Fe 3 O 4 @SiO 2 (Fe 3 O 4 @SiO 2 -NH 2 ) NPs. By taking advantage of the pH-responsive dynamic (covalent) imine bond between the hydrophilic Fe 3 O 4 @SiO 2 -NH 2 NPs and the hydrophobic cinnamaldehyde molecule (R), we developed dynamic covalent Fe 3 O 4 @SiO 2 (Fe 3 O 4 @SiO 2 -R) NPs with switching wettability . These NPs were then utilized to form Pickering emulsions , and whose stability and pH/magnetic response were thoroughly investigated. As the NPs concentration in the emulsion increased, the emulsion stability initially improved but then subsequently slightly decreased. Emulsifiers exhibited emulsifying effect on various oil phases, with paraffin oil demonstrating the best effect. By adding Hydrochloric acid to the emulsion, we successfully broke the imine bond at a pH value of 2.8, resulting in demulsification. Applying a magnetic field also achieved demulsification. After five cycles of pH or magnetic response-induced emulsification and demulsification, a stable Pickering emulsion could still be obtained. Stimuli-responsive Pickering emulsions have been extensively studied, but there is limited research on double-responsive Pickering emulsions. This study presents a novel design of Pickering emulsions with pH/magnetic dual responsiveness, offering great potential for oil-water separation applications.
研究领域:
材料科学
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化学工程
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界面科学
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
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2024
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IF 5.3
Hairong Wu,Kunpeng Hou,Guorui Xu,Genglin Li,Jiawei Chang,Tianfang Luan,Wenhao Shao,Jirui Hou
The CO2-responsive Pickering emulsions employed have garnered considerable attention across enhanced oil recovery agents, delivery of crude, and oilfield-produced fluid treatment. This study focuses on the design of an innovative type of Janus nanoparticle (JNP) and its application in the construction of CO2 stimuli-responsive Pickering emulsions. The emulsion stabilized by JNPs demonstrates swift phase separation subsequent to the injection of CO2. Furthermore, the mechanism of the CO2-stimulated responsiveness enabled by the JNPs was proposed. Based on the Schiff reaction, the synthesis of JNPs was achieved successfully via the Pickering emulsion template method. The properties of the JNPs were studied using various analytical techniques such as Fourier transform infrared, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, etc. The developed responsive system, composed of JNPs and sodium oleate surfactant, showed high interfacial activity at the oil/water interface. The study revealed that the responsive system-stabilized Pickering emulsions could remain stable at 70 °C and room temperature for 24 and 120 h, respectively. Furthermore, the introduction of CO2 for 1.5 min resulted in phase separation because the nanoparticles lost the amphiphilic nature, triggering a significant decrease in interfacial activity and the protonation of sodium oleate surfactant inactivation. Then, the particles started to desorb from the interface. This study proposes a convenient, simple, and cost-effective approach for preparing fast CO2-responsive Pickering emulsions. It provides novel insights into the advancement of oilfield-produced fluid treatment, transportation of crude oil, and enhanced oil recovery.
研究领域:
化学工程
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材料科学
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石油工程
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DOI
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
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2024
·
IF 3.9
Wei Liu,Yu-Qing Zhang,Zhen-Lin Dong,Zi-Xuan Chen,Lei Li,Xin-Yuan Zhao,Yang Wu,Yu-Yang Zhang
Graphical Here, the core-shell structure of ZIF-90@ZIF-67 was applied for the first time to catalyze the tandem reaction in Pickering emulsion system, which exhibited excellent catalytic performance with 99.9 % yield. Furthermore, ZIF-90@ZIF-67 has high stability and maintains good reproducibility after five cycles. This work provides a platform for the design of structurally and functionally diverse MOF-based interfacial catalysis for Pickering emulsions. Exploiting advanced solid particles is crucial to the construction of Pickering emulsions catalysis. Recently, metal-organic frameworks (MOFs) have been used as ideal emulsifiers stabilizing Pickering emulsions for interfacial catalysis. Although Pickering emulsions stabilized by core-shell MOFs have significant importance in practical studies, to date there have been very limited reports on this topic. Herein, ZIF-90@ZIF-67, a core-shell material with simultaneous acid-base bifunctionality, was synthesized by seeded epitaxial growth. It was firstly applied as an emulsifier in Pickering emulsions to catalyze the deacetalization-Knoevenagel tandem reaction, which exhibited excellent catalytic properties and achieved extremely high yields. Additionally, ZIF-90@ZIF-67 showed high stability and remained well repeatable after five cycles. This work provides a platform for the design of structurally and functionally diverse MOF-based Pickering emulsions interfacial catalysis.
研究领域:
材料科学
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催化化学
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产品关联
DOI
PubMed
高影响因子
Current Research in Food Science
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2024
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IF 6.2
Huan Gong,Lijia Chen,Guangyi Kan,Wenjie Zhang,Qiqi Qian,Xichang Wang,Jian Zhong
In this work, three types of benzenedialdehydes (1,2-, 1,3-, and 1,4-BDAs) were used to prepare BDA-crosslinked gelatin nanoparticles and the 1,2-BDA-crosslinked gelatin nanoparticle was explored to stabilize fish oil-loaded Pickering emulsions. The nanoparticle preparation was dependent on both pH and crosslinker types. 1,2-BDA and preparation pH of 12.0 induced the most nanoparticle amounts among the three BDAs and a pH range of 3.0–12.0. The crosslinked gelatin nanoparticles (10-nm scale) could aggregate to form larger nanoparticles (hundred-nanometer scale) in the water. The BDA crosslinking induced lower emulsifying properties (EAI: 10.2 ± 0.3 m 2 /g; ESI: 69.7 ± 3.6 min) for gelatin nanoparticles than gelatin (EAI: 30.9 ± 0.6 m 2 /g; ESI: 267.8 ± 2.0 min). With the increase of the gelatin nanoparticle concentrations (5–40 g/L), the emulsion viscosity increased (163 ± 9–422 ± 3 mPa s at the rotary speed of 60 rpm), the interfacial tension decreased (10.3 ± 0.2–7.2 ± 0.2 mN/m), and the creaming indexes decreased (42.1% ± 0.7%–13.3% ± 0.8% at day 21). The higher sodium chloride concentration (0.0–0.8 mol/L) induced the lower emulsion stability, even obvious phase separation (0.8 mol/L of NaCl). Therefore, the sodium chloride addition should be carefully considered for the development of emulsion-based foods. This work provided useful information for the development and application of protein nanoparticles.
研究领域:
食品科学
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材料科学
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界面化学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）