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Carbon fiber epoxy resin (CFRP) is gradually used as the space satellite antenna material, thermal control coatings (TCCs) are prepared on the surface to ensure the stable operation. However, the traditional TCCs have no wave transmission capability. The hollow glass microspheres (HGMs) were used to prepare the coating in our work, and ZrO2 was coated on its surface (Zr-HGM) to improve the solar reflectivity. The Zr-HGM powders were obtained by a homogeneous precipitation method with an appropriate reaction time of 4 h. By investigating the optical and dielectric properties, we found that the solar absorption of the coating with Zr-HGM was reduced by half compared to the coating with the original HGM. The microwave transmittances were all above 96.5% from 2 to 18 GHz. Our findings have proposed a preparation method for a new CFRP-based TCC, which will ensure the stable operation of the satellite antenna.

Background: Selective internal radiation therapy (SIRT) using a suitable β - -emitting radionuclide is a promising treatment modality for unresectable liver carcinoma. Yttrium-90 ( 90 Y) [ T 1/2  = 64.2 h, E β (max) = 2.28 MeV, no detectable γ-photon] is the most preferred radioisotope for SIRT owing to its favorable decay characteristics. Objective: Y]YAS) glass microsphere, a formulation biosimilar to "TheraSphere" (commercially available, U.S. FDA-approved formulation), for SIRT of unresectable liver carcinoma in human patients. 90 YAS glass microspheres of composition 40Y 90 Y]YAS) glass microsphere, a formulation biosimilar to "TheraSphere" (commercially available, U.S. FDA-approved formulation), for SIRT of unresectable liver carcinoma in human patients. Methods: YAS glass microspheres of composition 40Y 2 O 3 -20Al 2 O 3 Y]YAS glass microspheres were produced by thermal neutron irradiation of cold YAS glass microspheres in a research reactor. Subsequent to 2 (w/w) and diameter ranging between 20 and 36 μm were synthesized with almost 100% conversion efficiency and >99% sphericity. Intrinsically labeled [ 90 Y]YAS glass microspheres were produced by thermal neutron irradiation of cold YAS glass microspheres in a research reactor. Subsequent to in vitro Y]YAS glass microspheres were administered in human patients. in vivo studies in healthy Wistar rats, customized doses of [ 90 Y]YAS glass microspheres were produced with 137.7 ± 8.6 MBq/mg YAS glass (∼6800 Bq per microsphere) specific activity and 99.94% ± 0.02% radionuclidic purity at the end of irradiation. The formulation exhibited excellent Results: [ 90 Y]YAS glass microspheres in human patients showed near-quantitative retention of the formulation in the injected lobe. in vitro stability in human serum and showed >97% retention in the liver up to 7 d post-administration when biodistribution studies were carried out in healthy Wistar rats. Yttrium-90 positron emission tomography scans recorded at different time points post-administration of customized dose of [ 90 Y]YAS glass microspheres for clinical use in the treatment of unresectable hepatocellular carcinoma. Conclusions: The study confirmed the suitability of indigenously prepared [ 90 Y]YAS glass microspheres for clinical use in the treatment of unresectable hepatocellular carcinoma.

Rigid polyurethane foam (RPUF) as a filling material that can enhance the crashworthiness of thin-walled tubes. GO-HGMS hybrid was prepared by solution blending of graphene oxide (GO) and hollow glass microspheres (HGMS). The effect of the composite on the compression properties of RPUF was investigated. The GO-HGMS hybrid was characterized by fourier transform infrared spectroscopy (FTIR), x-ray diffraction(XRD), and scanning electron microscopy (SEM). The compression test and microstructure results show that the best compression performance and the largest apparent density of the composite foam were obtained when the hybrid content was 4 wt %. In addition, the compression test results of empty tubes (ET) and foam-filled tubes (FFT) under lateral load indicate that the combination of lightweight foamed material and thin-walled tube improves the stability of thin-walled tube deformation and the ability of the structure to resist deformation. GO-HGMS/RPUF as the filling material of thin-walled tube structure greatly improves the bearing capacity and energy absorption level of ET.

Improved heat transfer in composites consisting of guar gel matrix and randomly distributed glass microspheres is extensively studied to predict the effective thermal conductivity of composites using the finite element method. In the study, the proper and probabilistic three-dimensional random distribution of microspheres in the continuous matrix is automatically generated by a simple and efficient random sequential adsorption algorithm which is developed by considering the correlation of three factors including particle size, number of particles, and particle volume fraction controlling the geometric configuration of random packing. Then the dependences of the effective thermal conductivity of composite materials on some important factors are investigated numerically, including the particle volume fraction, the particle spatial distribution, the number of particles, the nonuniformity of particle size, the particle dispersion morphology and the thermal conductivity contrast between particle and matrix. The related numerical results are compared with theoretical predictions and available experimental results to assess the validity of the numerical model. These results can provide good guidance for the design of advanced microsphere reinforced composite materials.

The present work has the objective of studying the effect of shot peening with glass microspheres on SAE 1020 steel in its resistance to fatigue. Fatigue tests were carried out by rotary bending with load control and loading on balance in specimens with and without shot peening. A rotation speed of approximately 750 rpm (12.5 Hz) was employed in the fatigue tests. Vickers microhardness tests were performed in order to verify the surface hardening produced by shot peening with glass microspheres. Analysis of the steel surface and fatigue fractures was performed using scanning electron microscopy (SEM). Fatigue tests were performed in order to obtain S-N curves (Wöhler curves). It was observed that shot peening with glass microspheres improved the fatigue strength of the steel at high cycle.

Abstract The strategy of combining the traditional reinforcement of glass fibers (GF) with lighter hollow glass microspheres (HGM) can afford to fulfill the need for potential light-weight and high-strength modern materials required in various sectors, such as automotive and aerospace industry applications. This work fabricated composites of PA6/GF/HGM by melting blending in a co-rotating twin-screw extruder, and subsequently, injection molded. The effects of HGM content on the density, morphological and mechanical properties were investigated and the PA6/GF/HGM composites properties were compared to the properties of the traditional PA6/GF (70/30) wt% composite, widely used today in automotive industries. With the increase of HGM amount in the formulations, a reduction of between 3 and 12% in density was achieved with a slight reduction in its mechanical properties, showing that this new strategy can be applied to replace the PA6/GF (70/30) wt% composite, providing a considerable weight reduction for these materials.

In this work, it is reported a comparison between solid microspheres produced from glass having conventional industrial sand (IS) and glasses made with rice husk ashes (RHA) as a source of silica. The same composition was used to fabricate both glasses. The focused was the production of glass microspheres for road horizontal marking, which would attend the type classification called Premix. The microspheres were obtained by the horizontal flame method. The results showed that characteristics such as production yield, morphology, granulometry and, mainly, retroreflectivity measurements are not altered when rice husk ash is present in the glass composition, showing that this can be a sustainable alternative material for this important application.

Composites suitable for rotational molding technology based on poly(ε-caprolactone) (PCL) and filled with hollow glass microspheres (HGM) or functionalized hollow glass microspheres (HGMf) were prepared via melt-compounding. The functionalization of glass microspheres was carried out by a silanization treatment in order to improve the compatibility between the inorganic particles and the polymer matrix and achieve a good dispersion of glass microspheres in the matrix and an enhanced filler–polymer adhesion. The crystallization behavior of materials was studied by DSC under isothermal and non-isothermal conditions and the nucleating effect of the glass microspheres was proven. In particular, the presence of silanized glass microspheres promoted faster crystallization rates and higher nucleation activity, which are enhanced by 75% and 50%, respectively, comparing neat PCL and the composite filled with 20 wt% HGMf. The crystalline and supermolecular structure of PCL and composites crystallized from the melt was evaluated by WAXD and SAXS, highlighting differences in terms of crystallinity index and structural parameters as a function of the adopted crystallization conditions.

Strontium-doped mesoporous bioactive glass microspheres (Sr-MBGMs) were prepared by sol–gel method for delivering loxoprofen sodium (LX) drug. The loading capacity of the prepared Sr-MBGMs for LX drug was affected by the initial concentration of the drug solution and adsorption time. The LX-loaded Sr-MBGMs obtained under optimum conditions were coated with polydopamine (LX/Sr-MBGMs@PDA) and incorporated into the aminated modified poly-l-lactic acid nanofibrous matrix to develop a functional composite scaffold for bone tissue engineering applications. The in vitro studies revealed that the incorporation of the LX/Sr-MBGMs@PDA could promote cell proliferation and biomineralization, indicating that the as-developed composite scaffolds possessed an improved cell viability and osteogenic ability. [ABSTRACT FROM AUTHOR]

Glass microspheres are of great interest for numerous industrial, biomedical, or standalone applications, but it remains challenging to evaluate their elastic and optical properties in a non-destructive way. In this work, we address this issue by using two complementary contactless techniques to obtain elastic and optical constants of glass microspheres with diameters ranging from 10 to 60 µm. The first technique we employ is Brillouin Light Scattering, which yields scattering with longitudinal acoustic phonons, the frequency of which is found to be 5% lower than that measured in the bulk material. The second technique involves exciting the optical whispering gallery modes of the microspheres, which allows us to transduce some of their vibrational modes. The combined data allow for extracting the refractive index and the elastic constants of the material. Our findings indicate that the values of those properties are reduced with respect to their bulk material counterpart due to an effective decrease of the density, resulting from the fabrication process. We propose the use of this combined method to extract elastic and optical parameters of glass materials in microsphere geometries and compare them with the values of the pristine material from which they are formed.

This article presents data related to the research article entitled Considerations for readdressing theoretical descriptions of particle-filled composite food gels [1]. The elastic modulus of mixed biopolymer composite gels consisting of heat-set whey protein isolate and xanthan gum (WPI-X) filled with glass microspheres is reported. Gels were evaluated as a function of volume fraction filler (φf = 0-0.5), with varying filler size (4 μm, 7-10 μm, 45-90 μm, and 150-210 μm) and ionic strength of the protein phase (0, 50, 100, 200 mM NaCl). The reported elastic modulus data was extracted from large deformation uniaxial compression tests. This data is relevant to the development of alternative particle reinforcement models, or adaptation of existing theories. Further, it represents the limiting case of rigid inclusions, which can eliminate certain confounding assumptions in established models.

Syntactic foams with low density as well as low thermal conduction and proper mechanical performance are vitally important for aerospace, marine, and automotive industries. Here, phenolic-based syntactic foams were fabricated by combining the hollow glass microsphere (GMs) with phenolic resin of in situ synthesis. Benefited from the stirring and hot-pressing treatment, microspheres dispersed homogeneously in the resin matrix and it greatly reduced the density of the composites. Stretching and compression tests were performed to investigate the mechanical behavior of the foams. It is found that both the compressive and tensile strength decreased as the filler loadings increasing. While the elasticity modulus was improved. On the other hand, thermal properties tests revealed superior thermal stability and thermal insulate performance of the composites. The final residue content of the synthetic foam with 40 wt% filler was improved by ∼31.5% than that of the neat one at 700°C. And samples with 20 wt% microspheres reached a minimum thermal conductivity value of approximately 0.129 W (m·K)−1 which is ∼46.7% lower than that of neat resin [0.298 W (m·K)−1]. This work provides a feasible strategy to construct syntactic foams with low density and ideal thermal properties.