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Epoxy resins serve as useful material in anti-corrosion coatings. However, the development of microcracks during the processing or service life of a coating is an inevitable occurrence that markedly degrades its performance and shortens its lifespan. The incorporation of self-healing materials can prolong the coatings' lifespan and enhance the reliability of corrosion prevention processes. In this study, a microencapsulation method via integrating electrospraying and interfacial polymerization (ES-IP) was adopted to synthesize the microcapsules containing 4,4'-bis-methylene cyclohexane diisocyanate (HMDI) successfully. The self-healing capability of these microcapsules within the anti-corrosion coating was successfully validated. The prepared HMDI microcapsules (HMDI-MCs) demonstrate excellent dispersibility, tunable characteristics, and a high core material content of 93 wt%. Self-healing anti-corrosion coatings containing HMDI-MCs were prepared and underwent accelerated corrosion testing in sodium chloride (NaCl) solution. The result showed that HMDI is capable of leaking from microcapsules and undergoing solidification, thus forming a barrier to metal steel from corrosion hazards by endowing the coatings with effective self-healing abilities. This paper expands the application of the ES-IP technique in microencapsulation and suggests that HMDI-MCs have significant potential in self-healing anti-corrosion coating. [Display omitted] • HMDI microcapsule was successfully synthesized by ES-IP encapsulation technique. • HMDI microcapsule with core content of up to 93 % has a comprehensive quality. • Coating with HMDI microcapsules owns excellent self-healing anticorrosion property. [ABSTRACT FROM AUTHOR]

Oil-containing polymer composites have garnered significant attention in the field of tribology due to their remarkable environmental stability and outstanding self-lubricating performance. It is important to develop an oil-containing polymer composite with excellent self-lubricating properties and mechanical properties. In this study, we successfully synthesized hollow mesoporous carbon nanospheres (HMCNs) with a particle size of about 200 nm and explored the key factors affecting their preparation. Subsequently, an impregnation technique was employed to create oil-containing nanocapsules (Oil@C) by using PAO40 lubricant as core material and HMCNs as wall material. Self-lubricating PAO40@HMCNs nanocapsules have an oil content of approximately 51.6 wt%. The unique mesoporous structure of HMCNs facilitates the controlled release of lubricants. During friction, the Oil@C in the polymer composites continuously provided lubricant to the worn surface, resulting in a remarkable 72.8 % reduction in the coefficient of friction and an 83.2 % decrease in wear rate. Analysis of the friction pair revealed that the PAO40 lubricant released from the nanocapsules played a crucial role in improving the tribological properties of the composites. The prepared PA6 composites exhibit outstanding tribological and self-lubricating properties, making them promising candidates for applications in mechanical parts, such as self-lubricating slide bearings. [Display omitted] • The synthesis conditions of hollow mesoporous carbon nanospheres were determined. • The high impregnation rate(51.6 wt%) of the core material was achieved. • The PA6 composites containing Oil@C maintain good mechanical properties. • Oil@C-PA6 composites have excellent tribological properties. [ABSTRACT FROM AUTHOR]

The design of anti-icing structures is challenging for epoxy coatings, which are widely used in aircraft, wind power generation equipment, and outdoor buildings. Inspired by the principle that bird feathers are not easily frozen, a smart biomimetic anti-icing epoxy coating based on controlled-secreting hydrophobic small molecules in microcapsules was designed in this work. The remarkable feature of these microcapsules is that they can secreting small molecule oil at low temperature, but the release rate is very low at room temperature controlled by restriction of gel in the microcapsules' shell. Optical and SEM morphology showed that microcapsules were globe-shaped particles with compacted shells. FT-IR results indicated that the core material of glycerol trioctanoate was well protected by the shell skeleton of cross-linked methylated melamine-formaldehyde (HMMM) resin. Gelatin was filled in the microporous structure of the shell skeleton structure. AFM results showed that the gel material shrank at low temperatures, producing tiny holes in the shell material. The temperature sensitivity of gelatin was the valve for core release. The controlled-secreting property of microcapsules under various temperatures was measured using high-oil absorbent paper. Pore microstructure appeared on the shell of microcapsules after an alcohol delusion of the gel process. It was found that the secreting rate of the core material from the microcapsule was faster at low temperatures (-10∼ 20 °C) because of the shrinkage of gel material in the skeleton structure. SEM results also indicated that the microcapsules were dispersed homogeneously in the epoxy coating without any accumulation phenomenon. Moreover, the interface between microcapsules and epoxy resin was stable, and no interface separation debonding appeared even under the temperature of −20–40 °C. Surface hydrophobicity tests indicated that the epoxy coating with 3.0 wt% microcapsules had the largest water contact angle of 95°. The core material-secreting traces were observed, which confirmed that the hydrophobic small molecules migrated to the surface of the epoxy coating. Ice shear force values proved that more additive microcapsules provided more hydrophobic small molecules' secreting capacity to the coating's surface under a low temperature of −15 °C. This anti-icing function was sustainable and stable under violent temperature-change cycling, ensuring the coating material had a longer anti-icing service life. [Display omitted] • Smart bionic anti-icing epoxy coating was designed inspired by bird feathers. • Gelatin was filled in the microporous structure of the microcapsules' shell. • The secreting rate of the core material was faster at low temperatures. • The epoxy coating has a good anti-icing capability under a low temperature. [ABSTRACT FROM AUTHOR]

Double-inverse-opal (DIO) structured assemblies are three-dimensionally ordered porous materials containing core particles inside. In this work, DIO structured films composed of mobile inorganic colloidal particles within an organic polymer gel framework were developed. As the organic backbone, a poly(N -isopropylacrylamide) gel (PNIPAM gel) was employed to enhance the flexibility and processability of the films. A three-dimensional periodic structure of fluorescent-labelled silica core particles in the film was observed with confocal microscopy. Thermally induced volume transitions of the PNIPAM gels were observed, which showed the potential for stimuli-responsive optical materials. By selective etching of the sacrificial shell layers surrounding the core particles, cavities formed around the cores, and they exhibited random Brownian motion inside these pockets in the film. As a new type of organic-inorganic composite material, the proposed DIO structured films possessed unique characteristics originating from the combination of a flexible backbone and mobile cores, applicable to stimuli-responsive photonic devices, reusable catalytic particle assemblies, etc. [Display omitted] [ABSTRACT FROM AUTHOR]

This study explores the synthesis and characterization of microencapsulation of organic and eutectic phase change materials with a melting point ranging from 5 to 30 ℃ for low-temperature applications. Emulsion polymerization utilizing methyl methacrylate monomer as the shell material is employed for effective encapsulation. Comprehensive characterization of microcapsules is undertaken, including chemical composition (using Fourier transform infrared (FT-IR) spectroscopy), morphology (employing scanning electronic microscopy (SEM) and metallurgical microscope), particle size distribution (measured by ImageJ software), enthalpy (evaluated through differential scanning calorimetry (DSC)) and thermal degradation (explored via thermogravimetric analysis (TGA)). The successful production of microencapsulated phase change materials (MPCM) is confirmed by their two-phase decomposition process, the presence of specific chemical bonds, and the spherical morphology of particles with an average diameter between 25.63 and 49.62 μ m. However, in the case of eutectic core material, irregular microcapsules are shaped with a larger mean diameter. It has also affected the encapsulation efficiency in which around 29.43% and 30.1% efficiencies are reached for eutectic cores compared to 45.11% and 47% in organic ones. Simultaneously, thermophysical properties of MPCMs, such as density, thermal conductivity, and specific heat, are determined using the displacement method, transient line heat source, transient hot wire, and DSC. These properties are expressed through regression equations based on the determined effective factors. The derived equations enhance the capability to implement MPCMs in practical applications and numerical simulations. [Display omitted] • Microencapsulation of eutectic and organic phase change material. • Chemical and physical analysis of particles revealed issues in encapsulating eutectic materials. • Thermo-physical properties of microcapsules are measured. • Corresponding regression equations for thermal properties are reported to be applied in future studies. • Microcapsules can be nominated as promising candidates for cold chain applications. [ABSTRACT FROM AUTHOR]

Ice on the surface of outdoor equipment or aircraft under low temperatures often brings serious consequences. Functional coating materials with intelligent de-icing performance have become one of the research hotspots in materials science. Inspired by the bionic de-icing structure of penguin feather secretion oil, the aim of this work was to design and prepare an environmental-friendly intelligent de-icing epoxy coating surface with bionic microcapsule. The core material of the microcapsules is the hydrophobic oily liquid of glyceryl tri(2-ethylhexanoate) (C 27 H 50 O 6), which can be secreted from and the hexamethoxymethyl melamine resin (HMMM)/polyvinyl alcohol (PVA) shells. Morphology analysis confirmed that the microcapsules were successfully fabricated with core-shell structure and global shape. The microcapsules dispersed homogeneously in epoxy coating with an appropriate ratio of around 3.0–4.0 wt%. No interface debonding appeared between epoxy and microcapsules. Microcapsules had excellent thermal stability and resisted violent repetitive temperature changes without rupture. Chemical analysis of the shell confirmed the existence of gel PVA in pores of the cross-linked HMMM framework structure. Because the core materials penetrated shells through pores, it caused the increase in surface hydrophobicity of coatings. The release capability of the core material was enhanced by increasing the PVA content in shells and higher content of microcapsules in coatings. However, the excessive addition of microcapsules reduced the wear resistance of the epoxy coating. According to the ice shearing force test results, only 1.0 wt% addition of PVA/HMMM microcapsules significantly improved the de-icing performance of epoxy coating even under temperatures of − 20 °C. The reason was that the released oily molecules could dramatically reduce the adhesion between ice and epoxy. [Display omitted] • Intelligent de-icing epoxy coating surface was designed based on the bionics principle of feather secreting oil. • The hydrophobic core material diffused out of the HMMM/PVA microcapsules shells. • De-icing capability of epoxy coating blending with microcapsules had a sharply increase. [ABSTRACT FROM AUTHOR]

Ice on the surface of outdoor equipment or aircraft under low temperatures often brings serious consequences. Functional coating materials with intelligent de-icing performance have become one of the research hotspots in materials science. Inspired by the bionic de-icing structure of penguin feather secretion oil, the aim of this work was to design and prepare an environmental-friendly intelligent de-icing epoxy coating surface with bionic microcapsule. The core material of the microcapsules is the hydrophobic oily liquid of glyceryl tri(2-ethylhexanoate) (C 27 H 50 O 6), which can be secreted from and the hexamethoxymethyl melamine resin (HMMM)/polyvinyl alcohol (PVA) shells. Morphology analysis confirmed that the microcapsules were successfully fabricated with core-shell structure and global shape. The microcapsules dispersed homogeneously in epoxy coating with an appropriate ratio of around 3.0–4.0 wt%. No interface debonding appeared between epoxy and microcapsules. Microcapsules had excellent thermal stability and resisted violent repetitive temperature changes without rupture. Chemical analysis of the shell confirmed the existence of gel PVA in pores of the cross-linked HMMM framework structure. Because the core materials penetrated shells through pores, it caused the increase in surface hydrophobicity of coatings. The release capability of the core material was enhanced by increasing the PVA content in shells and higher content of microcapsules in coatings. However, the excessive addition of microcapsules reduced the wear resistance of the epoxy coating. According to the ice shearing force test results, only 1.0 wt% addition of PVA/HMMM microcapsules significantly improved the de-icing performance of epoxy coating even under temperatures of − 20 °C. The reason was that the released oily molecules could dramatically reduce the adhesion between ice and epoxy. [Display omitted] • Intelligent de-icing epoxy coating surface was designed based on the bionics principle of feather secreting oil. • The hydrophobic core material diffused out of the HMMM/PVA microcapsules shells. • De-icing capability of epoxy coating blending with microcapsules had a sharply increase. [ABSTRACT FROM AUTHOR]

The complex approach, which comprises both theoretical – solubility and miscibility parameter calculation – and experimental – use of membrane-assisted process – steps, may enable the design and implementation of a fully scalable process – membrane-assisted core-shell entrapment – to make novel types of curcumin (CUR) nanocarriers using both hydrophobically functionalized polyelestrolites and poly(L -lactide)/poly(lactide- co -glycolide) (PLLA/PLGA) blends. The optimal composition of the core material for CUR encapsulation was assessed using solubility and miscibility parameters, which were calculated utilizing different approaches – group increment methods by Hoy and Hoftyzer-van Krevelen as well as Hansen solubility parameters. Core-shell entrapment of CUR was performed by a membrane-assisted process using the LDC-1 set (Micropore Technologies). The nanocarriers were characterized using dynamic light scattering as well as scanning and transmission electron microscopy to determine their sizes, shapes and morphologies. UV-Vis spectrophotometry was used to analyze the CUR concentration in the nanocarriers and in vitro release profiles. The performed calculations show excellent compatibility between core components (PLLA, PLGA and CUR), confirmed by UV-Vis spectra and in vitro release profiles. The uniform sizes and shapes of the obtained nanocarriers show the very high potential of membrane-assisted core-shell entrapment of CUR into the nanoparticles as well as possible process control and upscaling. [Display omitted] [ABSTRACT FROM AUTHOR]

Due to relatively wide range of hues and great biocompatibility, natural dyes are now frequently employed in replacing synthetic dyes in many areas with high safety requirements. Natural dyes, however, are often ruined or faded in the process of storage and application because of their unique chemical structure. In this paper, packaging ink microcapsules with high stability and biocompatibility was prepared by in situ polymerization with polymethyl methacrylate (PMMA) as wall material, and gardenia blue (GB) natural dye as core material. The effects of the preparation parameters, such as dosages of the core material, emulsifier, and initiator on the morphology, structure, and stability of GB-PMMA microcapsules were characterized by means of scanner electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results showed that the encapsulation efficiency of GB-PMMA microcapsules can reach up to 84.8%. GB-PMMA microcapsules exhibit smooth and dense spherical appearance. Thermal stability of natural dye GB was improved by nearly 40% after being microencapsulated. Moreover, the adhesion and acid/alkali resistance grade of packaging ink containing GB-PMMA microcapsules are all higher than or equal to 3 level. Therefore, the GB-PMMA microcapsule samples prepared in this paper is expected to be used for printing ink of food packaging owing to their high stability and biocompatibility. [Display omitted] [ABSTRACT FROM AUTHOR]

In order to slow down the volatilization rate of N, N-Diethyl-m-toluidine (DEET) and enhance its safe application, an improved complex coacervation method was developed to encapsulated it to prepare microcapsules with the function of mosquito repellent. Tannic acid as a cross-linking agent for gelatin and Arabic gum enhanced the structural stability of the capsule through hydrogen bonding. Chitosan was selected to further deposited on the surface of G/AG MC for the improvement of pH stability and formed CS-G/AG MC. Scanning electron microscopy and optical microscope confirmed the chitosan was successful deposited on the G/AG MC, which ameliorated the agglomeration of microcapsules and promoted their monodispersity. Fourier transform infrared spectroscopy confirmed that electrostatic attraction accounted predominantly for the forces between the shell materials. The deposition of chitosan imparted controlled release to the microcapsules, resulting in a high retention efficacy of DEET in the pH range of 2–10. The CS-G/AG MC showed good storage stability and biocompatibility, and the static leakage of DEET within 40 days was negligible. The microcapsules prepared by this method showed green ecological properties, derived from the natural origin and biocompatibility of the shell material. And the tight structure of the microcapsule shell effectively barriered the volatile of DEET, while greatly extending its release time. This study can effectively protect the biological activity of core materials of microcapsules, and has long-lasting release performance, which has potential economic benefits in personal care products market directly contacted by humans. [Display omitted] [ABSTRACT FROM AUTHOR]

Lyocell fiber has attracted much attention in the textile fields as a greener alternative to viscose. Thermo-regulating Lyocell fiber, which composited with phase change materials (PCMs) and Lyocell fibers, would be desirable for making smart clothing with improved comfort. Herein, microencapsulated phase change materials (MPCMs) with polyurea shell and n-octadecane as core material were fabricated using regenerated nanochitin (RCh) as stabilizer via Pickering emulsion strategy. The size of MPCMs can be controlled by a tunable oil/water mass ratio (O/W). When the O/W ratio was above 1/25, the MPCMs exhibited melting enthalpy as high as 189.92 J/g with average size of less than 5 µm, which was suitable for spinning thermo-regulating Lyocell fibers. The thermo-regulating Lyocell fibers that were fabricated by a dry-jet wet spinning process showed high heat capacity (21.07 J/g) with a diameter of about 30 µm at 20 % loading microcapsules. They demonstrate good durability, where 95 % of the original heat capacity were retained after 100 heating/cooling cycles. [Display omitted] • The phase change microcapsules were prepared by Pickering emulsion polymerization using regenerated nanochitin as stabilizer. • The size of microcapsules can be controlled by a tunable oil/water ratio (O/W). • The thermo-regulating Lyocell fibers that fabricated by a dry-jet wet spinning process showed high heat capacity. [ABSTRACT FROM AUTHOR]

The purpose of this research is to develop a new type of core/wall material reinforced microcapsules by in-situ polymerization, which is applied to polyurethane foam (PUF) to prepared composite materials for cold chain transportation. The core material of MEPCMs was C 12 , modified with Nano-CuO; the wall material was Melamine-Formaldehyde (MF), modified with Carbon nanotubes (CNTs). The comprehensive performances of MEPCMs and composite materials were measured by SEM, FT-IR, XRD, DSC, LFA, and TGA. The results indicated that the addition of CNTs or Nano-CuO has almost no effect on the spherical structure of the MEPCMs, and the thermal conductivity increased 108% compared to the ordinary MEPCMs. The modified microcapsules also showed excellent cycling stability and thermal stability. Microencapsulated phase change materials (MEPCMs) helped PUF to form uniform and dense cells, and the cell structure became denser with the increasing content of MEPCMs. The cold storage capacity of the composite materials with 10.3 wt% MEPCMs was 83% higher than ordinary PUF. [Display omitted] • MEPCMs reinforced with Nano-CuO and CNTs were synthesized and characterized. • The reinforced MEPCEMs had perfect cycling stability and conductivity. • The composites of 10.3% MEPCMs and PUF were successfully prepared. • Potential application strategies of the MEPCMs/PUF were described. [ABSTRACT FROM AUTHOR]

The development of an efficient, durable and inexpensive catalyst for electrocatalytic water splitting is a daunting challenge and has attracted the interest of a large number of researchers. In this study, a novel oxygen evolution reaction (OER) electrocatalyst based on graphitic carbon nitride (g-C 3 N 4) layers encapsulated with Ni 2 P nanoflowers (Ni 2 P @ g-C 3 N 4) is synthesized, which exhibits low overpotentials of 237 mV for OER at 10 mA cm−2 and remarkable stability. The combination of the reactive Ni 2 P core and the chain-mail material is an important reason for the excellent electrocatalytic performance. The robust g-C 3 N 4 chain-mail protects the internal transition metal phosphides (TMPs) core from the harsh reaction environment, and well balances the catalytic activity and stability. As the core of the catalyst, the encapsulated Ni 2 P nanoflower core can transport electrons to the surface of the chain-mail layer. Our work demonstrates an efficient and robust Ni-based chain-mail electrocatalyst and provides a novel prospect for the development of the electrocatalyst. Chain-mail electrocatalyst Ni 2 P @ g-C 3 N 4 for oxygen evolution [Display omitted] • A facile chain-mail electrocatalyst Ni 2 P @ g-C 3 N 4 for oxygen evolution in alkaline solution. • The combination of the chain-mail material and the cores offers a method to engineer the electrocatalyst. • Extrinsic morphology and intrinsic electronic modulation synergistically boost the OER properties. [ABSTRACT FROM AUTHOR]

In nature, aquatic organisms such as barnacles (Cirripedia SPP.) and mussels (Mytilus SPP.) exhibit extraordinary underwater adhesion. Based on this, in this paper, silk fibroin (SF) and dopamine (DA) were mixed in an aqueous solution to obtain silk fibroin/polydopamine (SF-PDA) complex, and SiO 2 nanoparticles were prepared by sol-gel method. Then SiO 2 grafted SF-PDA was used as the wall material and carvacrol as the core material to obtain spherical structured nanocapsules (SSPM) with an average particle size of 332.60 nm. SF-PDA can generate double dynamic bonds (metal Fe3+ coordination bond and hydrogen bond), which can improve the crosslinking density of SSPM with silk. The results showed that the residual rate of carvacrol in silk treated with SSPM and FeCl 3 solution was about 19.20% after 15 times washing cycles, while the residual rate of pure carvacrol-treated silk was only 0.42% at 10 times washing cycles, indicating that the nanocapsule has good washing durability. In vitro biocompatibility assessment of human skin cells confirmed that the cells were safe and non-toxic after 24 h exposure to treated silk. The handle test shows that the treated silk hardly affects the original touch and improves the added value of the silk. SF is extracted from silk waste, which reduces environmental pollution and contributes to the sustainable development of industry. Double dynamic bonding provides a simple and green strategy for the preparation of nanocomposites with potential applications in functional textiles, medical textiles, advanced functional materials, etc. [Display omitted] [ABSTRACT FROM AUTHOR]

A series of nanoencapsulated phase change materials with n-tetradecane as the core material and melamine–urea–formaldehyde (MUF)–TiO 2 composite as the shell material was developed using a two-step method. Sol-gel and blending modification methods were respectively utilized after the in situ polymerization. The physical, chemical, and thermal properties of the nanoencapsulated phase change material (NEPCM) samples were characterized. Furthermore, a comprehensive performance evaluation system was established based on the efficacy coefficient method. The results indicated that the average diameter of the nanocapsules was significantly increased by the sol-gel modification and was slightly influenced by the blending method. All NEPCMs exhibited high chemical and thermal stability. The NEPCMs modified by the sol-gel method (C 14 @MUF–TiO 2 -S1) exhibited the best performance in terms of the encapsulation ratio, melting enthalpy, and onset decomposition temperature, which were 68.6%, 156.2 J·g-1, and 155.36 °C, respectively. C 14 @MUF–TiO 2 -S2 exhibited the lowest mass loss of 44.2% at 100 h. For the blending method, C 14 @MUF–TiO 2 -B1 had the highest yield of 53.87%. The thermal conductivity of C 14 @MUF–TiO 2 -B3 increased up to 88.15% compared with the unmodified NEPCMs. Therefore, modification by the sol-gel method with 2.2 g TiO 2 sol had the highest total efficacy coefficient of 0.843 among the samples. [Display omitted] • Nanocapsules with MUF–TiO 2 hybrid shell were developed and characterized. • The effects of sol-gel and blending modification were compared and analyzed. • A comprehensive performance evaluation system was established. • Nanocapsules modified by 2.2 g of sol through sol-gel method had the best performance. [ABSTRACT FROM AUTHOR]

Microfluidic technology has provided the possibility of double and multi-layered emulsion generation consisting of layers to project the core material which has several biomedical and industrial applications. However, limited numerical analysis and geometrical factors, as a powerful means of performance enhancement, are conducted in this literature. In this study, parametric research about the effects of characteristic design parameters on droplet generation by using Lattice Boltzmann Method is presented. In this regard, a new one-step model based on the co-flowing concept is designed and the influential geometrical factors are determined. Furthermore, each factor is optimized individually and a better outlook for further research and manufacturing is provided. The results are reported in terms of drop and droplet size, shell thickness and separations points. Consequently, for a specific purpose, the desired design parameters can be selected to increase the droplet generation performance. [Display omitted] • A novel microfluidic device design for double emulsion formation is presented. • A parametric study of geometrical factors of drop and droplet generation is conducted. • Double co-flowing concept is applied and the performance of device is optimized. • Depending on specific double emulsion production purposes, efficient geometrical values are reported. [ABSTRACT FROM AUTHOR]

Abstract: Stable, elastic and optical transparent microcapsules containing tetrachloroethylene as core material were prepared from gelatin, sodium dodecyl sulfate (SDS) and sodium carboxymethylcellulose (NaCMC) by complex coacervation method for electrophoretic display. Microcapsules were characterized by scanning electron microscopy, optical microscopy, and thermogravimetric analysis. It is suggested that SDS plays an important role during the process of microencapsulation, i.e. the existence of SDS increases the interaction between gelatin and NaCMC and facilitates the progress of complex coacervation. Because of the compact structure of the capsule wall, the microcapsules represent high thermal stability and good barrier property, both of which prevent core materials from penetrating outside the capsules. [Copyright &y& Elsevier]

The fish oil microcapsules were prepared via spray drying using octenyl succinic anhydride–linked starch (OSA-S) and maltodextrin (MD) as wall materials. The storage stability and in vitro release of entrapped oil were investigated in different storage temperatures and pH (3, 4, 5, 6, and 7). The structural properties of microcapsules were analyzed with scanning electron microscope. Results showed that the oxidation of fish oil microcapsule stored at 60 °C were more serious than 4 °C and 25 °C. Moreover, higher oxidation deterioration was found at pH 3, 4, and 5. For reconstituted emulsions (RCE) of microcapsule, 25 °C and pH 7 contributed to the physical stability, comparing to 60 °C and pH 3–6. Finally, higher release rate (83.73%) of encapsulated fish oil within simulated gastric fluid indicated that the wall materials complex was conducive to the bioavailability of core material under intestinal condition. Herein, the results of this investigation will enrich the comprehensive understanding of the appropriateness of the combination of octenyl succinic anhydride-linked starch and maltodextrin as encapsulation materials. [Display omitted] • HHigher oxidation deterioration of fish oil microcapsule were found at 60 ℃ and pH 3-5. • 25 ℃ and pH 7 were contributive to the physical stability of capsule reconstituted emulsions, comparing to 60 ℃ and pH 3–6. • Higher release rate (83.73%) of microcapsules within SGF was conducive to the bioavailability of core material. [ABSTRACT FROM AUTHOR]

Using stearic acid as the core material and calcium carbonate doped with nano iron as the hybrid shell material, a dual-functional microcapsule was prepared by in-situ polymerization method. The microstructure and thermal properties of the microcapsules were analyzed by scanning electron microscopy, Fourier transform infrared spectrometer, differential scanning calorimeter, and thermogravimetric analyzer, and the infrared stealth effect was evaluated by a thermal infrared imager. The results showed that the phase change temperatures are 47–68 °C and 72–74 °C in the solidifying and melting processes, respectively, and the maximum phase transition enthalpy is about 161 J/g. The infrared emissivity decreased about 54.7% via nano iron insertion. The enhanced infrared stealth property will widen the microcapsule application besides the thermal energy domain. [Display omitted] • A phase change microcapsule composite was realized by an amphiphilic surfactant molecule. • CaCO 3 shell was formed by Ca2+ and CO 3 2- in-situ polymerization reaction. • Microcapsules have thermal storage and infrared stealth characteristics. • Microcapsules exhibited a good thermal stability. [ABSTRACT FROM AUTHOR]

Abstract: Spontaneous imbibition (SI) is a very important oil recovery mechanism from low-permeability fractured reservoirs. However, this process will not take place if the reservoir rock is preferential oil-wet. Recently, it was discovered that SI into preferential oil-wet carbonate is possible if the porous medium is exposed to a water-phase containing cationic surfactants of the type CnTAB. Estimation of SI rates for aqueous surfactant solutions into preferential oil-wet carbonates based on the diffusion equation approach have been performed in this work. Capillary diffusivity coefficients (CDCs) were calculated for SI tests into preferential oil-wet carbonates and compared to corresponding data for imbibition of water into strongly water-wet chalk (reference wettability state). The diffusion approach is especially suitable for SI driven by a foregoing wettability alteration process induced by surfactants due to problems to measure dynamic flow parameters accurately during the wettability alteration process. The solution to the three-dimensional diffusivity equation describing oil recovery as a function of time is expressed by an infinite series. Approximating the solution using only one term in each spatial direction makes it possible to calculate CDCs after performing a least square fit on experimental data. The results show that CDCs for SI into preferential oil-wet carbonates are in the range (1.7–14)×10-11m2/s, which are approximately three orders of magnitude lower than for SI of water into strongly water-wet chalk. However, CDCs for imbibition into preferential oil-wet carbonates are still larger than what is observed for cores having mixed-wettability of which have the exponential decay parameter λ reduced up to four orders of magnitude compared to imbibition into strongly water-wet core material [N.R. Morrow, G. Mason, Curr. Opin. Colloid Interf. Sci. 6 (2001) 321–337]. The calculated CDC for imbibition into strongly water-wet chalk shows good agreement with other values published in the literature. [Copyright &y& Elsevier]

As a kind of typical functional substance, the wide application of surfactants causes growing concern about potential environmental safety hazard while benefiting mankind a lot, exploring approaches to achieve low cost, low risk and high performance is of great significance. In this paper, microcapsules encapsulating surfactant were prepared through solvent evaporation method, using hydrophobic ethyl cellulose as the shell material, which endowed the microcapsules environmental-friendliness and oil-phase targeting effect. Nonionic surfactant Span 20 was used as core material as an example. The mechanisms for the generation of the microcapsules and the effects of several factors, such as the stirring speed, core/shell weight ratio and molecular weight of ethyl cellulose, on the properties of the microcapsules were investigated, by which how to adjust the size and the mechanical properties of the microcapsules were determined. The oil-phase targeting performance of the microcapsules was verified, it was confirmed that the microcapsules could break rapidly when they encounter with oil phase interface, releasing surfactant to reduce the oil-water interfacial tension, while the microcapsules keep stable in water medium. Thereby in the practical applications of surfactants, the temperature resistance and salt resistance performance could be enhanced, and the interfacial efficiency could be achieved at low surfactant dosage. This work reveals a newly approach to employ surfactants smartly and more efficiently, and might have great potential in many fields. [Display omitted] • Span 20 surfactant was microencapsulated with EC shell via solvent evaporation method. • The mechanisms for the generation of the microcapsules were investigated. • The prepared microcapsules have the oil-phase targeting performance. • The microcapsules have temperature resistance and salt resistance. [ABSTRACT FROM AUTHOR]

Multifunctional microcapsules with paraffin as core materials and polystyrene (PS)/modified graphene oxide (GO) as shell materials were prepared via Pickering emulsion polymerization, which was further reduced by ascorbic acid to obain paraffin@PS/Rγ-GO phase change microcapsules. Then the microcapsules were blended with waterborne silicone resin to form a coating that was coated and dried on the fabric to obtain a multi-protective fabric coating. The morphology and properties of microcapsules were measured, and hydrophobicity, anti-static electricity and thermal insulation properties of the coatings were investigated. The results showed that the O/W Pickering emulsion was more stable by using silane coupling agent modified GO as stabilizer. When the content of microcapsules in coatings reached to 70 wt%, the water contact angle (WCA) and slide angle (SA) of the prepared coating were 153.8° and 8.3°, respectively. Moreover, the multi-protective coating could keep the anti-static electricity even after 5 times water washing, and it had a good thermal insulation property, which could be applied in many outdoor goods and special protective equipments for multi-protection. [ABSTRACT FROM AUTHOR]

• A new microencapsulated 1-dodecanal organic PCM (MicroPCM) was synthesized. • Spherical microcapsules had average particle size of 490.2 nm and were amorphous. • MicroPCM showed good latent heat (79.45 kJ/kg) and encapsulation efficacy (40.9 %). • MicroPCM was thermally stable (∼130 °C) and had high TES capacity of 91.2 %. • MicroPCM was thermally reliable with an index of 94.4 % even after 200 cycles. In this study, a new microencapsulated organic PCM (MicroPCM) was developed and its thermal energy storage (TES) properties were experimentally investigated. The microcapsules were prepared through a facile in-situ polymerization process using 1-dodecanol as the core PCM and the melamine-formaldehyde as the shell material. The microstructural analysis results infer that, the as-prepared microcapsules were spherical in shape, and the existence of carbon, oxygen and nitrogen elements have confirmed the effective formation of the MicroPCM. The average particle size (490.2 nm), surface roughness and with no chemical interaction between the core and the shell materials have paved way for achieving improved storage stability of the MicroPCM. The microcapsules with high thermal storage capability of 91.2 % have exhibited good latent heat of fusion of 79.45 kJ/kg. The microcapsules were thermally stable up to 132.82 °C, which was substantially higher than that of the operating temperature range of the pure PCM. The measured thermal conductivity of the MicroPCM was relatively lower (0.1727 W/m K) which has satisfied the thermal insulation criteria as well. The thermal cycling test conducted for microcapsules showed excellent thermal reliability (reliability index of 94.4 %). Also, no chemical interaction was observed between the core and the shell materials even after 200 heating/cooling process. Based on the test results, it is inferred that, the MicroPCM with enhanced properties can be a promising candidate for low temperature thermal energy storage. [ABSTRACT FROM AUTHOR]