Formation Of Microspheres Research Articles

Bi-phase metallic cobalt with efficient broadband absorption in X and Ku bands

Broadband and lightweight microwave absorbers have gained considerable research interest in overcoming electromagnetic interference pollution. Here, mixture of two phase (fcc and hcp) metallic cobalt powders with broadband absorption was synthesized through solvothermal method using ethylene glycol as the reducing agent. The effect of NaOH content on the structure and morphology of the prepared Co powders is investigated by X-ray diffraction and field-emission scanning electron microscopy. Ring samples of 7.00/3.04 mm of out/inner diameter were prepared with paraffin for microwave absorption testing by vector network analyzer. It was observed that the increase of NaOH content caused a relative higher generation of hcp-Co phase and formation of irregular microspheres. The reflection loss (RL) peak and effective absorbing bandwidth (EABW, RL ≤ − 10 dB) shifted towards lower frequency when the sample thickness increased from 1.00 to 3.00 mm with EABW covering almost all the C, X and Ku bands (4–18 GHz). The bi-phase Co prepared in a low base solution exhibited enhanced microwave absorption properties. The width of largest EABW has reached 6.33 GHz covering partial Ku band and almost all the X band with optimal RL of − 56.95 dB at a sample thickness of only 1.85 mm, which is superior to EABW of Co crystals reported earlier. We proposed that such a wide EABW is due to the fact of Z values closed to 1.0 (0.8 ≤ |Z| ≤ 1.2) at almost the whole frequency range. This indicates that the prepared bi-phase Co powders are excellent microwave absorbers with large bandwidth, have good prospects.

Controlled synthesis of porous CaCo2O4 nanoflowers and their multifunctional applications for lithium ion batteries and oxygen evolution reaction

A facile two-step method is developed to synthesize three dimensional (3D) hierarchical CaCo2O4 architectures as high-performance electrode materials for lithium ion batteries (LIBs) and oxygen evolution reaction (OER). Our strategy involves a simple poly(vinylpyrolidone) (PVP)-assisted hydrothermal route and subsequent thermal treatment to produce flowerlike CaCo2O4 nanostructures with a size of ∼500 nm, which is constructed by some neighboring vertical nanoplates. Whereas, the absence of PVP results in the formation of CaCo2O4 microspheres, further indicating the vital role of PVP in favor of the oriented crystal growth of Co-based oxides. Benefited from the unique structural features, the resultant CaCo2O4 nanoflower presents excellent cycling stability (∼560 mAh g−1 after 100 cycles at 50 mA g−1) and remarkable rate capability. Apart from superior lithium storage properties, more strikingly, CaCo2O4 nanoflower demonstrates a promising candidate as a noble metal-free electrocatalyst for oxygen evolution reaction, which will spur us to find more novel functional nanomaterials for wide applications.

Unique CdS@MoS2 Core Shell Heterostructure for Efficient Hydrogen Generation Under Natural Sunlight

The hierarchical nanostructured CdS@MoS2 core shell was architectured using template free facile solvothermal technique. More significantly, the typical hexagonal phase of core CdS and shell MoS2 has been obtained. Optical study clearly shows the two steps absorption in the visible region having band gap of 2.4 eV for CdS and 1.77 eV for MoS2. The FESEM of CdS@MoS2 reveals the formation of CdS microsphere (as a core) assemled with 40–50 nm nanoparticles and covered with ultrathin nanosheets of MoS2 (Shell) having size 200–300 nm and the 10–20 nm in thickness. The overall size of the core shell structure is around 8 µm. Intially, there is a formation of CdS microsphre due to high affinity of Cd ions with sulfur and further growth of MoS2 thin sheets on the surface. Considering band gap ideally in visible region, photocatalytic hydrogen evolution using CdS@MoS2 core shell was investigated under natural sunlight. The utmost hydrogen evolution rate achieved for core shell is 416.4 µmole h−1 with apparent quantum yield 35.04%. The photocatalytic activity suggest that an intimate interface contact, extended visible light absorption and effective photo generated charge carrier separation contributed to the photocatalytic enhancement of the CdS@MoS2 core shell. Additional, the enhanced hole trapping process and effective electrons transfer from CdS to MoS2 in CdS@MoS2 core shell heterostructures can significantly contribute for photocatalytic activity. Such core shell heterostructure will also have potential in thin film solar cell and other microelectronic devices.

In vitro Characterization of Microspheres Containing Chemically Cross- Linked Gummy Exudates of Cochlospermum religiosum

Background: The polymeric hydrocolloids of natural origin such as gums and mucilages have their own significance in food and pharmaceutical industries due to safety, cost, biodegradability, biocompatibility, etc. Objective: This study includes the assessment of feasibility of gummy exudates of Cochlospermum religiosum for development of microspheres through emulsification technique. Methods: The effects of exudates concentration, glutaraldehyde amount and process temperature were analyzed on particle-size and swelling dynamics of developed microspheres. The formulations were also characterized by thermal decomposition and powder X-ray diffraction technique to assess the effect of crosslinking. Results: The photomicrographs of preparations revealed the formation of microspheres with smooth, spherical and free-flowing nature. The swelling dynamics followed Fick’s diffusion mechanism for swelling media. Fourier transform infrared spectroscopy showed the formation of ether-linkage after crosslinking of exudates by glutaraldehyde. The thermogravimetric curves disclosed the formation of strong bonds during crosslinking. Conclusion: The ease of gummy exudates of Cochlospermum religiosum for microspheres formation ascribed the potential of these formulations to incorporate therapeutic agent(s) to be applied as novel drug-carriers.

One-pot sonochemical synthesis of 3D flower-like hierarchical AgCl microsphere with enhanced photocatalytic activity.

A highly uniform 3D flower-like hierarchical AgCl microsphere was prepared by sonochemical method with the existence of β-dextrin. The 3D flower-like hierarchical structure can be ascribed to the existence of β-dextrin, which provides nucleation sites for the growth of nanosheets because of the strong interaction between β-dextrin and Ag+. The 3D flower-like hierarchical AgCl microspheres were assembled by numerous interleaving nanosheet petals with small thickness. Benefiting from the unique structural features, the as-prepared 3D flower-like hierarchical AgCl microsphere exhibited higher degradation efficiency with degrading 98.17% of methylene blue (MB) and 88.50% of tetracycline (TC) within 40 min, which were both remarkably higher than those of irregular AgCl under visible light irradiation. Besides, the photocatalytic degradation rate constant of 3D flower-like hierarchical AgCl microsphere (0.063 min-1) for MB was 3.94 times higher than that of irregular AgCl (0.016 min-1). Moreover, a possible mechanism for the formation and excellent photocatalytic performance of 3D flower-like hierarchical AgCl microsphere was also proposed.

One-Pot Formation of Sb-Carbon Microspheres with Graphene Sheets: Potassium-Ion Storage Properties and Discharge Mechanisms.

Low-cost rechargeable batteries are ardently required for large-scale energy storage applications. In this regard, nonaqueous potassium-ion batteries (KIBs) are ascendant candidates due to the abundance of potassium resources, yet their energy density and cycle stability are insufficient for practical use. In this study, we report the Sb-based multicomposite comprising Sb nanoparticles, amorphous carbon (C), and reduced graphene oxide (rGO) as an anode material for KIBs. By adopting the tartaric acid as a carbon source and a chelating agent simultaneously, a multicomposite electrode with uniform and fine-sized Sb particles is realized. The Sb-C-rGO multicomposite exhibits a reversible capacity of 310 mAh g-1 at 0.5 A g-1 and 79% of it is retained after 100 cycles. Electrochemical tests show that the capacity fading in the Sb-C-rGO cell is attributed to the side reactions in the K metal and electrolyte, rather than the degradation of Sb nanoparticles. Furthermore, the formation of the metastable product is elucidated by Ostwald's step rule and density functional theory calculations. The present synthesis approach and the understanding of the failure and working mechanisms provide general insight into developing the alloying-type electrode materials for rechargeable batteries.

Paramagnetic CoS2@MoS2 core-shell composites coated by reduced graphene oxide as broadband and tunable high-performance microwave absorbers

Nowadays, developing microwave absorbers with tunable and high-efficiency electromagnetic absorbing performance is still facing many challenges, in spite of their wide applications in civilian and military roles. Here, flower-like CoS2@MoS2 core-shell microspheres coated by reduced graphene oxide (rGO) is designed and synthesized by a facile hydrothermal method. The formation of typical flower-like core-shell microspheres is attributed to the combined effect of CoS2 microsphere and MoS2 nanosheet during hydrothermal reaction process. Further, with the addition of graphene oxide, the wrinkled rGO nanosheet is successfully coated on the surface of flower-like CoS2@MoS2 core-shell microspheres, forming a specific three-dimensional (3D) structure. The microstructure, morphology and chemical composition of the as-synthesized composites are characterized by XRD, Raman, XPS, SEM and TEM. Magnetic measurement shows that CoS2@MoS2 microspheres exhibit paramagnetic behavior. The electromagnetic properties of CoS2@MoS2/rGO composites are measured by a vector network analyzer, where the unique flower-like core-shell structure and multiple interfaces, particular surface defects as well as the specific electric properties of CoS2, MoS2 and rGO lead to the impressive microwave absorption properties. The effect of filler loading ratio on microwave absorption performance of the wax-based absorbers is analyzed in detail. It is noted that the sample with 20 wt% loading of CoS2@MoS2/rGO exhibits optimal reflection loss (RL) characteristics, where the minimum RL is −58 dB with a broad effective bandwidth of 6.24 GHz from 11.76 to 18 GHz at 2.4 mm. Apparently, the as-synthesized CoS2@MoS2/rGO composites can be acted as a lightweight and broadband microwave absorber with low filler loading. This work offers a new strategy to design high-performance and tunable microwave absorbers with individual microstructure and morphology using a facile, low-cost and environmental-friendly synthesis route.

Surfactant induced formation of flower-like V2O5 microspheres as cathode materials for rechargeable magnesium batteries

Flower-like V2O5 microspheres were synthesized via a facile hydrothermal route with hexadecyl trimethyl ammonium bromide (HTAB) surfactant. However, the irregular V2O5 assemblies formed in the absence of HTAB. In particular, the cathode based on V2O5 microflowers can deliver superior discharge capacity, better cycling stability, and enhanced rate capability, compared with that based on irregular assemblies. Specially, it can deliver considerable discharge specific capacity (an initial capacity of 126.2 mAh g−1 at 50 mA g−1), good cycling stability (90.7 mAh g−1 after 80 cycles), and enhanced rate capability (above 60 mAh g−1 at 200 mA g−1). The improved electrochemical performance for V2O5 microflowers may be due to the increased specific surface area, interspace, and flexibility. The discharge-charge mechanism was investigated by X-ray diffraction and X-ray photoelectron spectroscopic results. This work indicates the important role of the surfactant on morphology control of cathode active materials for the promotion of electrochemical performance of rechargeable magnesium batteries.

Perylene diimide derivative regulate the antimony sulfide morphology and electrochemical sensing for hydrazine

Sb2S3/perylene diimide derivatives composite micro-spheres composed of slight dendrites were synthesized by solvothermal reaction. Perylene diimide derivative with two carboxyl groups at amine position as morphology-controlling reagent is the key factor for determining the microscopic morphology of Sb2S3 in this system. Time-dependent experiments have been conducted to track the formation of Sb2S3 micro-spheres. Moreover, the composite material showed an excellent sensitivity of 29.8 μA mM−1 cm2 with a low detection limit of 50 pM, it also showed better stability and selectivity in hydrazine detection. This approach not only regulate the morphology and composition of Sb2S3 submicron materials effectively, but also provide new ideas for the manufacture of metal sulfide- perylenediimide amino acid derivative materials, which will be suitable for sensing, catalysis, and photovoltaic applications.

Interaction of femtosecond laser radiation with titanium in a liquid hydrocarbon medium

A method for the synthesis of microspheres coated with titanium carbide is described. The processes occurring in the region of the action of laser radiation are considered. The formation of microspheres was carried out by the action of femtosecond laser radiation on the surface of titanium located in the reaction medium - the ultimate hydrocarbon. The hydrocarbon source was the medium in which the treatment was carried out. The obtained microspheres have an average size of 1-3 μm and can be used in applications of additive engineering, powder metallurgy as the main raw material, or as an alloying additive.

Single-Emulsion P(HB-HV) Microsphere Preparation Tuned by Copolymer Molar Mass and Additive Interaction.

Herein, we describe the production of poly(hydroxybutyrate-co-hydroxyvalerate) [P(HB-HV)]-based microspheres containing coumarin-6 (C6) or pyrene (Py) fluorophores as additives and models for hydrophobic and hydrophilic drug encapsulation. Their photophysical and morphological properties, as well as encapsulation efficiencies, are studied as this work aims to describe the influence of additive hydrophobicity/hydrophilicity on microparticle formation. These properties were studied by scanning electron microscopy, fluorescence confocal laser scanning microscopy (FCLSM), and steady-state fluorescence spectroscopy. The results show that the surfactant concentration, polymer molar mass, emulsification stirring rate, and the presence of the fluorophore and its nature are determinants of the P(HB-HV) microsphere properties. Also, encapsulation efficiency is shown to be governed by synergic effects of these parameters on the formation of microspheres. Moreover, size distribution is proved to be strongly influenced by the surfactant poly(vinyl alcohol) content. FCLSM showed that the fluorophores were efficiently encapsulated in P(HB-HV) microspheres at distinct distributions within the copolymer matrix. Surprisingly, nanospheres were observed in the microsphere surface, suggesting that microspheres are formed from nanosphere coalescence.

Control of octreotide release from silk fibroin microspheres

Poly(d,l-lactide-co-glycolide) (PLGA) microspheres have been used as an injectable depot for prolonged release of octreotide (Sandostatin LAR®), a peptide drug for the treatment of acromegaly and gastrointestinal tumors. However, acylation and incomplete release of the encapsulated octreotide, as well as acidic degradation product-induced inflammation are the major challenges hampering widespread clinical applications of this delivery system. The purpose of this study was to develop a novel octreotide-delivering system utilizing naturally derived biodegradable material, silk fibroin (SF). Octreotide acetate was encapsulated in the SF microspheres with a high loading (8–10 wt%) using polyethylene glycol (PEG)-assisted emulsification method. The octreotide-SF microspheres exhibited a silk I structure (low crystallinity) and burst release in in vitro release studies. Ethanol treatment after microsphere formation significantly increased β-sheet and silk II structure (high crystallinity) of the microspheres, significantly reducing the burst release and resulting in zero-order sustained release of octreotide over 102 days, and the data could be fit to the diffusion-driven release model. After the ethanol-treated microspheres were intramuscularly injected into rats at low (2 mg/kg) and high (8 mg/kg) octreotide doses, the plasma concentration of octreotide in the high dose group remained high (>50 pg/mL) at day 28 when compared to that of the control (pure drug at low dose) and low dose microsphere group. Interestingly, the plasma concentration for the high dose group at day 56 dramatically increased to >280 pg/mL observed at day 28. The low dose microsphere group showed a similar increase, but at a much lower level. The rebound octreotide level likely reflected degradation of the SF matrix which released tightly bound/trapped octreotide. Therefore, SF microspheres can deliver octreotide over a long period of time with release kinetics and the mechanism different from PLGA microsphere system.

Preparation and characterization of Alendronate depot microspheres based on novel poly(-ε-caprolactone)/Vitamin E TPGS copolymers

In the present study, new aledronate (AL) loaded microspheres were prepared with the use of polycaprolactone (PCL)/Vitamin E d-ɑ-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS) copolymers. Specifically, PCL-TPGS copolymers, prepared at several PCL to TPGS ratios (namely, 90/10, 80/20, 70/30 and 60/40 w/w) via a ring opening polymerization process, were characterized by intrinsic viscosity, proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and enzymatic hydrolysis. Results showed that as TPGS content increases the intrinsic viscosity of the copolymer (and hence, the viscosity-average molecular weight) is decreasing, while FTIR analysis showed the formation of hydrogen bonds between the CO of PCL and the OH of TPGS. Additionally, XRD analysis indicated that the prepared copolymers were semi-crystalline in nature, while enzymatic hydrolysis studies showed that increasing TGPS content led to increasing copolymer hydrolysis. In the following step, AL drug-loaded microspheres were prepared via single emulsification process. Scanning electron microscopy (SEM) revealed the formation of coarse drug-loaded microspheres with particle size close to 5 μm, while XRD analysis showed that the API was amorphously dispersed only in the cases of high TPGS content. Furthermore, FTIR analysis showed that the API did not interact with the copolymer components, while in vitro drug release studies showed that increasing PCL content led to decreasing API release rate. Finally, analysis of the drug release profiles suggested that the API release mechanism was solely governed by the polymer matrix erosion.

Role of Steam as a Medium for Droplet Crystallization

Mannitol and sodium chloride (NaCl) were spray dried using a counter current superheated spray dryer. Superheated steam was found to induce relatively high nucleation during the solidification of the sprayed droplets when compared to hot air. This allowed the production of spherical mannitol particles with very fine crystals at a lower temperature. In addition, superheated steam led to the formation of unique salt microspheres consisting of hollow hopperlike sodium chloride crystals. These unique particle morphologies were not observed in hot air spray drying. Further analysis revealed that higher droplet temperature during the constant rate drying period, under superheated steam conditions, led to the high nucleation phenomenon. Results from this work illustrate the potential of superheated steam as a useful medium for in situ crystallization control in spray dryers.

Long noncoding RNA MALAT1 mediates stem cell-like properties in human colorectal cancer cells by regulating miR-20b-5p/Oct4 axis.

Cancer stem cells (CSCs) are crucial components of the tumor microenvironment that take part in tumor initiation, progression, recurrence, metastasis, and resistance to chemotherapy. This study explores the mechanisms through which CSCs maintain their stemness, especially in tumors of colorectal cancer (CRC), which thus far remain uncertain. Our findings indicated that the expression of miR-20b-5p is negatively correlated with that of metastasis-associated lung adenocarcinoma transcript-1 (MALAT1, r = -0.928, p = 0.023) and Oct4 (r = -0.894, p = 0.041) in CRC cells. We hypothesized that there may be some targeted regulatory relationships among MALAT1, miR-20b-5p, and Oct4. We proceeded to show that both si-MALAT1 and miR-20b-5p-mimic attenuated microsphere formation and self-renewal capacity, decreased the proportion of CSCs, and downregulated the expression of proteins associated with tumor cell stemness maintenance (Oct4, Nanog, sex-determining region Y-box 2, and Notch1) and cellular metabolism (glucose transporter 1, lactate dehydrogenase B, hexokinase 2, and pyruvate kinase isozyme M2) in HCT-116 cells in vitro. In addition, a xenograft model based on Balb/c mice demonstrated that the administration of either si-MALAT1 or miR-20b-5p-mimic suppressed the tumorigenicity of HCT-116 cells in vivo. The underlying mechanisms may involve the targeting of the tumor cell stemness maintenance-related factor Oct4 by miR-20b-5p. For the first time, we present the possible underlying effects of MALAT1 in influencing the stem cell-like properties of CRC cells. We propose that microRNAs and longnoncoding RNAs have vital functions in mediating tumor stemness, which remain to be fully elucidated.

Fabrication of Bi2SiO5 hierarchical microspheres with an efficient photocatalytic performance for rhodamine B and phenol removal

Self-assembled three-dimensional (3D) Bi2SiO5 microspheres were synthesized via a solvothermal method using glycerol as reaction media and NH3•H2O as pH adjustment. The growth of Bi2SiO5 crystal was influenced by the solvothermal time. During the preparation process, glycerol acts as a soft template to guide the formation of the hierarchical microspheres. The photocatalytic activities of Bi2SiO5 microspheres toward the degradation of Rhodamine B and phenol under light irradiation were evaluated. Bi2SiO5 microspheres display much higher photocatalytic activity than the Bi2SiO5 nanoplates. The high photocatalytic activity of hierarchical Bi2SiO5 microspheres can be ascribed to the enhanced light absorbance, the efficient separation of photo-generated electrons and holes and the large surface area. The main active species during the photocatalytic reaction are •OH and •O2−, proven by terephthalic acid photoluminescence probing technique and nitroblue tetrazolium (NBT) experiments. The Bi2SiO5 microspheres are stable during the photocatalytic reaction and can be used repeatedly.

Hollow-structured pollucite microspheres and the formation mechanism

Abstract Pollucite (CsAlSi2O6·nH2O) with ANA zeolite structure could be synthesized by using metakaolin (MK), silica fumes (SF) and CsOH·H2O under hydrothermal conditions without any surfactants and seeds. Hollow-structured pollucite microspheres were obtained when the Si/Al molar ratio was above 2.0. The as-prepared hollow-structured microspheres were observed to have hierarchically structure with hollow inner and micro to mesoporous shell. Results showed that the earlier generated cesium aluminum silicate precursors through the rapid reaction of MK and CsOH could be deposited on the surface of SF microspheres to form a core-shell structure. Then further dissolution of SF microspheres in core led to the formation of hollow-structured pollucite microspheres. Self-sacrifice template effect of SF microspheres with relatively lower dissolution rate than MK was proposed to explain the formation of hollow microspheres. It is observed that the adsorption capacity of hollow-structured pollucite microspheres for methylene blue (MB, 50 mg/L) at 20 °C could reach to 52.44 mg/g, which higher than that of MK or SF. Hollow-structured pollucite microspheres might be applied as adsorbent, catalyst carrier and micro-reactor.

Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst.

The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

Preparation of golf ball-shaped microspheres with fluorinated polycaprolactone via single-solvent electrospraying for superhydrophobic coatings

1H,1H,2H,2H-Perfluorooctyl polyacrylate (PTFOA) with a controllable molecular weight was successfully synthesized via atom-transfer radical polymerization (ATRP) followed by condensation with polycaprolactone (PCL) to obtain a new fluorinated block copolymer. Then, the copolymer PCL-b-PTFOA was processed via single-solvent electrospraying in chloroform to fabricate hierarchically porous microspheres. The microsphere size could be controlled from 5.13 ± 0.51 μm to 8.61 ± 0.90 μm, and the pore size on the microsphere surface could be controlled from 282.5 ± 42.0 nm to 603.3 ± 99.6 nm. Solvent evaporation-induced phase separation and fluorinated segment migration are the major reasons for the formation of the golf ball-shaped microspheres. In this study, the influence of electro-spraying parameters on the size and morphology of the porous microspheres was systemically studied. The golf ball-shaped microspheres significantly improved the surface roughness and the CA of their coatings reached 167.3 ± 1.7°. Furthermore, a superhydrophobic fabric was produced by pretreating cotton fabric with adhesive followed by coating with PCL-b-PTFOA via electrospraying. The robust superhydrophobicity can be obtained by the stable binding of PCL-b-PTFOA microspheres onto the fibers, with the CA reaching 155.3 ± 1.1°. Electrospraying of the fluoropolymer microsphere coating was proven to be a very promising technique to produce superhydrophobic coatings on textiles through a simple procedure.

Mechanisms of Forming Hollow Microspheres from Solid Granules

Problems in fabrication of large-size hollow microspheres with specific properties and ideal geometric parameters for inertial confinement fusion and other applications require profound knowledge of their formation processes. In this work, we analyze experimentally and analytically the formation of hollow microspheres from solid spherical granules by high-temperature foaming and formulate the conditions for fabrication of microcapsules with high parameters in high-temperature processes.