Size controlling of monodisperse carboxymethyl cellulose microparticles via a microfluidic process

Monodisperse carboxymethyl cellulose containing phenolic groups (CMC‐Ph) microdroplets with a radius of 100–400 μm and a coefficient of variation below 3% were produced in a coflowing microfluidic device. The CMC‐Ph solution containing horseradish peroxidase was used as the disperse phase and liquid paraffin containing H₂O₂ and lecithin as the continuous phase. The size of microdroplets decreased with the decreasing diameter of the inner channel and concentration of the disperse phase. When using a 0.04% CMC‐Ph solution and the device with the inner diameter of 160 μm, the size of the microdroplets can be further controlled by the flow rates of both the continuous phase and disperse phase following exponential models. The volume of the microdroplet was not inversely proportional to the flow‐rate ratio of the continuous phase to the disperse phase. There was a weak dependence of the volume on the flow of the continuous phase. The monodisperse microparticles possessed potential application for sensor, drug delivery system, cell encapsulation, catalysis, and imaging. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40663.     

Gas hold‐up in bubble columns: Operation with concentrated slurries versus high viscosity liquid

The hydrodynamics of bubble columns with concentrated slurries of paraffin oil (density, ρ_L = 790 kg/m³; viscosity, μ_L = 0.0029 Pa·s; surface tension, σ = 0.028 N·m¹) containing silica particles (mean particle diameter d_p = 38 μm) has been studied in columns of three different diameters, 0.1, 0.19 and 0.38 m. With increasing particle concentration, the total gas hold‐up decreases significantly. This decrease is primarily caused by the destruction of the small bubble population. The hold‐up of large bubbles is practically independent of the slurry concentration. The measured gas hold‐up with the 36% v paraffin oil slurry shows remarkable agreement with the corresponding data obtained with Tellus oil (ρ_L = 862 kg/m³; μ_L = 0.075 Pa·s; σ = 0.028 N·m^?1) as the liquid phase. Dynamic gas disengagement experiments confirm that the gas dispersion in Tellus oil also consists predominantly of large bubbles. The large bubble hold‐up is found to decrease significantly with increasing column diameter. A model is developed for estimation of the large bubble gas hold‐up by introduction of an wake‐acceleration factor into the Davies‐Taylor‐Collins relation (Collins, 1967), describing the influence of the column diameter on the rise velocity of an isolated spherical cap bubble.     

Preparation and properties of phase‐change heat‐storage UV curable polyurethane acrylate coating

Phase‐change heat‐storage UV curable polyurethane acrylate (PUA) coating was prepared by applying microencapsulated phase change materials (microPCMs) to PUA coating. MicroPCMs containing paraffin core with melamine‐formaldehyde shell were synthesized by in situ polymerization. The effect of stirring speed, emulsification time, emulsifier amount, and core/shell mass ratio on particle size, morphology, and phase change properties of the microPCMs was studied by using laser particle size analyzer, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopic analysis, scanning electron microscopy, and differential scanning calorimetry. The results showed that the diameter of the microcapsules decreased with the increase of stirring speed, emulsification time, and emulsifier amount. When the mass ratio of emulsifier to paraffin is 6%, microcapsules fabricated with a core/shell ratio of 75/25 have a compact surface and a mean particle size of 30 μm. The sample made under the above conditions has a higher efficiency of microencapsulation than other samples and was applied to PUA coating. The dispersion of microPCMs in coating and heat‐storage properties of the coating were investigated. The results illustrated that the phase‐change heat‐storage UV curable PUA coating can store energy and insulate heat. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41266.     

Spray‐dried microparticles composed of cinnamoyl poly(N‐isopropylacrylamide‐co‐hydroxyethylacrylate) and gold nanoparticle

Temperature‐ and NIR irradiation‐responsive microparticles composed of cinnamoyl poly(N‐isopropylacrylamide‐co‐hydroxyethylacrylate) [CinP(NIPAM‐HEA)] and gold nanoparticle (GNP) were prepared by a spray‐drying method. According to the cloud points determined by an optical method, the HEA content in P(NIPAM‐HEA) had no marked effect on the lower critical solution temperature (LCST). However, the cinnamoyl group content in CinP(NIPAM‐HEA) had a significant effect on the LCST. The LCSTs determined by a calorimetric method was in agreement with those determined by an optical method. The hydrodynamic mean diameter of gold nanoparticle (GNP) prepared by reducing gold ions was about 30 nm and it seemed to be a nanosphere on TEM photo. Spray‐dried CinP(NIPAM‐HEA) microparticles containing GNP was 1.5 μm to 12 μm in diameter on SEM photo. Gold was detected on the energy‐dispersive X‐ray spectrum of the microparticles. The amount of FITC‐dextran released for 12 h from the microparticles was much higher at temperatures above the LCST (at 37 °C and 45 °C) than below the LCST (at 20 °C and 25 °C). The cumulative release amount in 12 h was only about 3% without NIR irradiation, whereas the value was about 26.5% when NIR was irradiated to the microparticle suspension. The photothermal energy generated by GNP was believed to render the thermosensitive copolymers de‐swollen and hydrophobic, allowing for the active release of dye from the microparticles. The NIR irradiation‐responsive GNP‐loaded microparticles could be applied to the development of NIR‐responsive drug carriers which release their contents in response to an external stimulus (i.e., NIR irradiation). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44141.     

Preparation of polymer microspheres in supercritical carbon dioxide and their evaluation as cold‐flow improvers in diesel

Polymeric microspheres were synthesized by the precipitation copolymerization of methacrylic acid and styrene in supercritical carbon dioxide. Scanning electron microscopy showed that the products were spherical microparticles. The mean diameter of the particles was 0.2–2 μm. The synthesis conditions affecting the particle size and morphology were examined in detail. The well‐distributed copolymer microspheres were applied as low‐temperature improvers for diesel. The results showed excellent performance for high‐paraffin diesel at low temperatures. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and characterization of double‐MF shell microPCMs used in building materials

A kind of double‐shell heat energy storage microcapsule was prepared used melamine formaldehyde (MF) resin as shell material, and the properties of the microcapsules were investigated. A phase change material, with melt point of 24°C and phase transition heat of 225.5J/g, was used as core. The microcapsules would be used in indoor walls to regulate the temperature and save energy. The surface morphological structure was examined by means of scanning electron microscopy. The strength of the shell was evaluated through observing the surface change after pressure by means of scanning electron microscopy. The average diameter of the microcapsules was 5 μm ～ 10 μm. Diameter of 1 μm ～ 5 μm could also be obtained by using different stirring speeds. The globular surface was smooth and compact. The thickness was 0.5 μm ～ 1 μm. Also, the melting point of the microcapsules was 24.7°C, nearly equal to the pure phase change material. The DSC results make clear that the polymer shell of the microcapsules does not influence the properties of the phase change material. It was also found that the avoiding penetration property of the double‐shell microcapsules was better than that of single shell, and the average diameter of 5 μm was better than 1 μm. With the increase of ratio of the core material, the compactability decreased, and the shell thickness decreased. The mass ratio of core and shell was 3 : 1 to ensure that the microcapsules had good heat storage function. The measuring test showed that the microcapsules did not rupture at a pressure of 1.96 × 10⁵ Pa. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1755–1762, 2005     

Synthesis and characterization of chitosan/urea‐formaldehyde shell microcapsules containing dicyclopentadiene

Microcapsules containing healing agent have been used to develop the self‐healing composites. These microcapsules must possess special properties during the use of composites such as stability in surrounding, appropriate mechanical strength, and lower permeability. A new series of microcapsules containing dicyclopentadiene with chitosan/urea‐formaldehyde copolymer as shell materials were synthesized by in situ copolymerization technology. The microencapsulating mechanism was discussed and the process was explained. Also, the factors influencing the preparation of microcapsules were analyzed. The morphology and shell wall thickness of microcapsules were observed by using scanning electron microscopy. The size of microcapsules was measured using optical microscope and the size distribution was investigated based on data sets of at least 200 measurements. The chemical structure and thermal properties of microcapsules were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis, respectively. The storage stability and isothermal aging experiment of microcapsules were also investigated. Results indicted that the chitosan/urea‐formaldehyde microcapsules containing dicyclopentadiene were synthesized successfully; the copolymerization occurred between chitosan and urea‐formaldehyde prepolymer. The microcapsule size is in the range of 10–160 μm with an average of 45 μm. The shell thickness of microcapsules is in the range of 1–7 μm and the core content of microcapsules is 67%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Interface stability behaviors of methanol‐melamine‐formaldehyde shell microPCMs/epoxy matrix composites

Microcapsules containing phase change materials (microPCMs) have been widely applied in smart temperature‐controlling materials. Interface stability plays a key role in these microPCMs/matrix composites. The aim of this study was to investigate the interface stability behaviors of methanol‐melamine‐formaldehyde (MMF) shell microPCMs containing paraffin/epoxy matrix composites. MMF prepolymer can be applied to fabricated microcapsules with smooth shells. The average diameter of the microPCMs could be controlled in the range of 5–45 μm by stirring speed of 500–6,000 r min⁻¹. From the SEM morphologies of the interphase between the microPCMs and the epoxy‐matrix, it is concluded that the interaction may be enhanced by MMF graft structure due to the increasing of molecular interaction in the interface. During a repeated heat‐transmission process, not only the repeated‐times of thermal absorbing‐releasing process will damage the interface bonding, but also higher thermal conductive speed will make the interface bearing more debonding stress. Large microPCMs in matrix may supply better interface stability. Moreover, the numerical and experimental results are consistent to obtain a clear insight into the rule of interface debonding for microPCMs/matrix composites that the interface perfection can be enhanced by increasing the thickness of interphase. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Fabrication of Thermally Stable Polysulfone Microcapsules Containing [EMIm][NTf2] Ionic Liquid for Enhancement of In Situ Self‐Lubrication Effect of Epoxy

Microcapsules containing an ionic liquid (IL) are potential candidate materials for preparing in situ self‐lubricating composites with excellent tribological properties. 1‐ethyl‐3‐methylimidazolium bis[(trifluoromethyl) sulfonyl]imide ([EMIm]NTf₂) IL encapsulated polysulphone microcapsules are synthesized. The mean diameter and wall thickness are about 128 μm and 10 μm, respectively. Microcapsules have excellent thermal stability, with a thermal degradation onset temperature of 440 °C compared to traditional lubricants‐loaded microcapsules. In situ self‐lubricating composites are prepared by incorporating the IL‐encapsulated microcapsules into epoxy matrix. When the concentration of the IL microcapsules is 20 wt%, the frictional coefficient and specific wear rate of composites are reduced by 66.7% and 64.9% under low sliding velocity and middling applied load conditions, respectively, as compared to the neat epoxy. The tribological behavior of the self‐lubricating composites is further assessed in different applied load and sliding velocity conditions. The in situ self‐lubricating mechanism of composites is proposed.

     

Microcapsules prepared from a polycondensate‐based cement dispersant via layer‐by‐layer self‐assembly on melamine‐formaldehyde core templates

Novel microcapsules were prepared from colloidal core–shell particles by acid dissolution of the organic core. Weakly crosslinked, monodisperse and spherical melamine‐formaldehyde polycondensate particles (diameter ～ 1 μm) were synthesized as core template and coated with multilayers of an anionic polyelectrolyte via layer‐by‐layer deposition technique. As polyelectrolytes, an anionic naphthalenesulfonate formaldehyde polycondensate that is a common concrete superplasticizer and thus industrially available, and cationic poly(allylamine hydrochloride) were used. Core removal was achieved by soaking the core–shell particles in aqueous hydrochloric acid at pH 1.6, resulting in hollow microcapsules consisting of the polyelectrolytes. Characterization of the template, the core–shell particles, and the microcapsules plus tracking of the layer‐by‐layer polyelectrolyte deposition was performed by means of zeta potential measurement and scanning electron microscopy. The microcapsules might be useful as microcontainers for cement additives. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fabrication of size‐controllable mPEG‐decorated microparticles conjugating optically active ketoprofen based on self‐assembly of amphiphilic random copolymers

Novel size‐controllable mPEG‐decorated polymeric microparticles binding optically active ketoprofen were successfully fabricated based on chemoenzymatic synthesis and self‐assembly of amphiphilic random polymer–ketoprofen conjugates with mPEG and (S)‐ketoprofen as pendants. A series of mPEG₃₅₀‐ or mPEG₁₀₀₀‐functionalized amphiphilic random polymer–ketoprofen conjugates with drug loading capacity from 16.5% to 73.2% were easily prepared by combining enzymatic resolution with radical polymerization and characterized by Fourier Transform Infrared spectroscopy, ¹H‐NMR, and gel permeation chromatography. The formation of aggregates from the amphiphilic random polymer–ketoprofen conjugates was investigated by ultraviolet‐visible absorption spectra using pyrene as the guest molecule. Transmission electron microscopy measurement revealed that the self‐assemblies were well dispersed as spherical microparticles. The size of the self‐assemblies could be widely tuned by varying the length of mPEG chains and the content of ketoprofen in the synthetic polymer–ketoprofen conjugates, and a series of mPEG‐decorated (S)‐ketoprofen‐bound polymeric microparticles with average radius from 70 nm to 1.1 μm were obtained. The successful preparation of the microparticles containing (S)‐ketoprofen provided a new strategy for the design and fabrication of optically active drug delivery systems. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Influence of the geometric factors of the experimental device used in suspension polymerization on the properties of poly(styrene‐co‐divinylbenzene) microparticles

The prediction of the final particle size for reactive systems such as the reactions of suspension polymerization is a complex matter. Thus, the preparation of very small microparticles is specially challenging, probably because of the coalescence of the polymeric beads taking place during the later stages of the polymerization. In this work, very small gel‐type styrene‐co‐divinylbenzene beads were synthesized by using a previously determined set of experimental synthesis conditions in which the stabilization of the dispersion of the monomeric droplets was ensured, and, under these conditions, the factors related to the geometry of the experimental device were modified to determine their actual effect on the final size of the microparticles. From the experimental results, a very simple and useful model was obtained that was able to predict the final size of the microparticles as a function of the values of the geometric factors of the reactor. This model indicates that the most influential factors in the final size of the microparticles are the liquid depth inside the reactor and the stirrer diameter; thus, an increase in the liquid depth produces larger particles, and, conversely, the particle size decreases when using larger stirrer diameters. Additionally, the model permits the design of polymerization experiments aimed at obtaining microparticles with a diameter smaller than 50 μm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of paraffin/TiO2‐P(MMA‐co‐BA) phase change material microcapsules for thermal energy storage

Microcapsules based on a phase changing paraffin core and modified titanium dioxide–poly(methyl methacrylate‐co‐butyl acrylate) [P(MMA‐co‐BA)] hybrid shell were prepared via a Pickering emulsion method in this study. The microcapsules exhibit an irregularly spherical morphology with the size range of 3–24 µm. The addition of BA can enhance the toughness of the brittle polymer poly(methyl methacrylate) and improve the thermal reliability of the phase change microcapsules. The ratio of BA/MMA is in the range of 0.09–0.14, and the ratio of the monomer/paraffin is varied from 0.45 to 0.60. These microcapsules exhibit a well‐defined morphology and good thermal stability. The actual core content of the microcapsules reaches 36.09%, with an encapsulation efficiency of 73.07%. Furthermore, the prepared microcapsules present the high thermal reliability for latent‐heat storage and release after 2000 thermal cycles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46447.     

Ultralow Tribological Properties of Polymer Composites Containing [BMIm]PF6‐Loaded Multilayer Wall Microcapsule

Multilayer wall microcapsules efficiently loaded with a lubricant (ionic liquid [BMIm]PF₆) are successfully synthesized via a combination of interfacial and in situ polymerization reactions based on lignin nanoparticle–stabilized Pickering emulsion templates. The resulting microcapsules are spherical in shape, with an ideal structure of a rough outer surface and a smooth inner surface. The mean diameter and wall thickness of the resultant microcapsules are 52 ± 18 µm and 3–6 µm. The core fraction is ≈71.29 wt%. Compared with the pure epoxy resin, the friction coefficient of self‐lubricating composites decreases by 83.6% (from 0.55 to 0.09) and the wear rate decreases by 218 times (from 76.8 × 10^?14 to 0.352 × 10^?14 m³ N^?1 m^?1) by incorporating 20 wt% of the resultant microcapsules into the epoxy resin. It is demonstrated that [BMIm]PF₆, a more efficient lubricant, release from the microcapsules during the friction process produced a boundary lubricating film. The bipolar property of [BMIm]PF₆ makes the lubricating film firmer, which can efficiently prevent direct contact between the resin matrix and counterface. Furthermore, the rough poly(urea‐formaldehyde) outer surface of multilayer microcapsules brings in an improved interface property between the microcapsules and resin matrix.     

Preparation and characterization of polyurea/polyurethane double‐shell microcapsules containing butyl stearate through interfacial polymerization

Double‐shell microcapsules containing butyl stearate were prepared through interfacial polymerization. The outer shell is polyurea formed through polymerization of toluene‐2,4‐diisocyanate (TDI) and diethylene triamine, and the inner shell is polyurethane (PU) formed through polymerization of TDI and polypropylene glycol 2000 (PPG2000). Styrene maleic anhydride copolymer was used as emulsifier. The effects of core to monomer ratio and dosage of PPG2000 on core content and encapsulation efficiency of microcapsules were investigated. The core content has a maximum at core to monomer ratio of 3–4, and the encapsulation efficiency has a maximum value of 95% at core to monomer ratio of 2. The prepared microcapsules were smooth and compact and have an obvious latent heat of 85 J/g. The shell structure of microcapsules was polyurea and PU. The average diameter of the microcapsules was 1–5 μm. The stabilities of the double‐shell microcapsule, such as anti‐ethanol wash and antiheat properties are obviously improved than those of single‐shell microcapsule. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

明胶-阿拉伯树胶电子墨水微胶囊表界面控制

以明胶-阿拉伯树胶为壁材,四氯乙烯为分散介质,硬脂酸改性的TiO2为显示颗粒,采用复合凝聚法制备了红白显示的电子墨水微胶囊。讨论了表面活性剂十二烷基硫酸钠(SDS)对复合凝聚相生成过程的影响,并分析了Span 80用量对微胶囊形貌的影响。结果表明,SDS与明胶间形成的复合凝聚相具有很高的表面活性。此外,Span 80体积分数为2.0%～3.0%时,制备的微胶囊囊壁光滑、均一,平均粒径约为60μm。制备的微胶囊在电场强度为2.5×106V/m时,具有良好的电场响应行为及可逆移动性。     

Drug‐loaded microparticles prepared by the one‐step deposition of calcium carbonate/alginate onto cotton fabrics

Calcium carbonate (CaCO₃)/alginate inorganic–organic hybrid particles were synthesized and deposited on to the surface of cotton fabrics with a novel one‐step procedure. The effects of the Ca²⁺/CO₃^2?/alginate molar ratio on the cotton matrix were investigated. The optimization of the process resulted in a regular shaped hybrid microparticles, and scanning electron microscopy revealed that the particles were uniformly distributed on the surface of the fibers. Dynamic light scattering showed that the particles were about 2 μm in diameter. Moreover, transmission electron microscopy images demonstrated that the core–shell structure of the particles existed along with CaCO₃ evenly enfolded into the alginate layer. An X‐ray diffraction pattern displayed that the alginate/CaCO₃ hybrid microparticles were a mixture of calcite and vaterite crystal. Fourier transform infrared spectroscopy indicated that CaCO₃/alginate hybrid particles formed in situ were the only deposited materials. The thermogravimetric analysis curve indicated a certain mass ratio of the alginate and CaCO₃ in the hybrid particles. Furthermore, the drug‐loading and drug‐release properties of the hybrid microspheres were studied, and the results show that the water‐soluble diclofenac sodium could be effectively loaded in the hybrid microparticles and the drug release could be effectively sustained. Finally, both of the microparticles and modified fabrics had good cytocompatibility. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42618.     

Preparation and properties of poly(propylene carbonate maleate) microcapsules for controlled release of pazufloxacin mesilate

A novel biodegradable aliphatic polycarbonate, poly(propylene carbonate maleate) (PPCMA) was synthesized by terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride (MA), using a polymer supported bimetallic complex as catalyst. The utility of PPCMA to encapsulate and control the release of drug pazufloxacin mesilate (PZFX), via microcapsules, was investigated. PPCMA microcapsules containing PZFX were elaborated by solvent evaporation method based on the formation of double W/O/W emulsion. The manufacturing parameters such as the volume ratio of V(PPCMA) : V(PZFX), the concentration of stabilizer gelatin in outer aqueous phase played major roles on microcapsule characters, and were altered to optimize the process parameters. The PPCMA‐PZFX microcapsules were obtained with smooth and spherical surface under optimum condition, the mean diameter of microcapsules was ～ 2 μm, and the drug loading and drug encapsulation efficiency of the microcapsules were 22.9 ± 1.05% and 82.1 ± 2.03%, respectively. PZFX released from PPCMA microcapsules was found to reach 89.8 ± 2.89% after 36d in a pH 7.4 phosphate‐buffered solution, and the release profile obeyed the Higuchi equation. The results suggest that the new polymer PPCMA provides an alternative to degradable matrix polymers for long‐term sustained releasing drug delivery systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Microcellular foaming of low‐density polyethylene using nano‐CaCo3 as a nucleating agent

In this study, microcellular foaming of low‐density polyethylene (LDPE) using nano‐calcium carbonate (nano‐CaCO₃) were carried out. Nanocomposite samples were prepared in different content in range of 0.5–7 phr nano‐CaCO₃ using a twin screw extruder. X‐ray diffraction and scanning electron microscopy (SEM) were used to characterize of LDPE/nano‐CaCO3 nanocomposites. The foaming was carried out by a batch process in compression molding with azodicarbonamide (ADCA) as a chemical blowing agent. The cell structure of the foams was examined with SEM, density and gel content of different samples were measured to compare difference between nanocomposite microcellular foam and microcellular foam without nanomaterials. The results showed that the samples containing 5 phr nano‐CaCO₃ showed microcellular foam with the lowest mean cell diameter 27 μm and largest cell density 8 × 10⁸ cells/cm³ in compared other samples. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Mechanical properties and drug release of microcapsules containing quaternized‐chitosan‐modified reduced graphene oxide in the capsular wall

Reduced graphene oxide (rGO) sheets were first modified with 2‐hydroxypropyltrimethyl ammonium chloride chitosan (HACC), and these modified rGO sheets (named HACC–rGO) were used as reinforcement materials and introduced to the walls of chitosan (CS) microcapsules. All of the monodisperse microcapsules were conveniently generated by a gas–liquid microfluidic technique. The results of scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis all demonstrate that the HACC–rGO sheets existed and were dispersed in the capsular shell. The HACC–rGO‐reinforced CS microcapsules showed better mechanical strength and better chemical stability with an α‐cyclodextrin solution than the CS microcapsules without HACC–rGO. Importantly, the HACC–rGO‐reinforced CS microcapsules exhibited a slower drug‐release behavior and provide a method for the control of the release rate of drug‐loaded microcapsules. In an in vitro cytotoxicity evaluation by a 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide assay, the Schwann cells still showed good cell viability after they were treated by extracts of the CS/HACC–rGO microcapsules with concentrations ranging from 0.02 to 2000 μg/mL. Therefore, the HACC–rGO‐reinforced CS microcapsules are promising for applications in the fields of drug delivery and controlled release. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44549.