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Hierarchically structured micrometric mesoporous silica spheres have been synthesized by evaporation driven self assembly of silica colloids under slow drying condition. The inter particle correlation inside grains has been investigated by small-angle neutron scattering. In a slow drying regime, droplets shrink isotropically leading to spherical dried grains. However, the packing of nanoparticles depends on the initial colloidal concentration. The packing of the nanoparticles for low colloidal concentration is uniform throughout the grain but at higher concentration of the colloids, dried grains possess nonuniform radial packing of the nano-particles. The average packing fraction of the nanoparticles decreases with increasing colloidal concentration due to modification in viscosity of the colloidal dispersion prior to drying.

Novel flower-like composite architecture was successfully synthesized by spray drying and post-calcinating method for the first time. Scanning electron microscopy and transmission electron microscopy observations confirmed that reduced graphene oxides/carbon nanotubes hybrid (rGO/CNTs) formed a flower-like micrometer structure and Cu₂O, CuO (Cu_xO, x = 1 or 2) nanoparticles were decorated inside them. The photocatalytic properties were further investigated by evaluating the photodegradation of a pollutant methyl orange (MO). The experimental results indicated that this novel architecture enhanced photocatalytic performance with 96.2% decomposition of MO after 25 min in the presence of H₂O₂ under visible light irradiation, which was much higher than that of Cu_xO powders (33.2%). This could be attributed to the more efficient adsorption of MO molecules on flower-like rGO/CNTs and provide a high concentration of MO near to the Cu_xO nanoparticles, thus promoting the photocatalytic degradation process.

Despite the fact that silicon material can be synthesized from various sources, deriving them from silica resources is of strategic significance for the industrial processing. Here a low-cost nano/micro structure of Si–CNT was derived from nano-SiO₂ and multiwall carbon nanotubes (MWCNTs) with simple methods. By employing table salt (NaCl) as a heat scavenger for the magnesiothermic reduction, the nano/micro structure of the material was remained effective. Comparing to ball milling, a combination of SiO₂, MWCNTs and NaCl by spray drying achieved the long cycle life for Si–CNT composite. This material presented a stable capacity above 968.1mAh g${}^{-1}$ with excellent capacity retention of 85.4% at the 150th cycle versus the 2nd one. The Si nanoparticles, very small particle size in 10–20nm, homogenously dispersed in electronically conductive network of MWCNTS, which accommodate the volume change of Si and reinforce highly conductivity of the Si–CNT composite during repeated cycles. Combined with its low-cost and up-scaling technologies, Si–CNT composite is a promising anode material in rechargeable lithium batteries with high electrochemical performance.

The SiO_x/Si composite enhanced by dual-carbon (i.e., multiwall carbon nanotubes and carbon) was fabricated from the micro silicon monoxide (SiO) by the combination of high-energy mechanical milling, spray drying and pyrolysis. The obtained SiO_x/Si particles were composed of Si-suboxide and embedded nano-sized Si crystallites. As one of dual-carbons, the multi-walled carbon nanotubes were directly scaffolded of anchoring the SiO_x/Si composite particles through spray drying. Another carbon source was directly deposited on the surface of the SiO_x/Si by means of the carbonization of phenol–formaldehyde resin. Nano-sized silicon embedded in the Si-suboxide matrix and dual-carbon provided a compromise between the reversible capacity and cycle stability related to the volume change. The obtained SiO_x/Si/MWCNT/PC-1 electrode delivered an initial capacity of 936.5mAh g${}^{-1}$ and the reversible capacity was maintained at 825.9mAh g${}^{-1}$ with excellent capacity retention of 87.5% on the 200th cycle versus the 6th one (compared with the same current rate). In contrast, although the SiO_x/Si presented the higher initial capacity of 1271.4mAh g${}^{-1}$, its capacity dropped quickly after several cycles and capacity retention was only 25.6% versus the 6th cycle after 100 cycles.

The hierarchical TiO₂/C microspheres were obtained via a facile method of in-situ hydrolysis and spray drying. Antase TiO₂ nanoparticles were coherent to microspheres TiO₂/C due to the pyrolysis of carbon source (PVP). Besides, the favorable electron transfer from carbon to TiO₂ improves the electronic conductivity of TiO₂ via the presence of Ti–C bond within TiO₂/C composite. Charge-discharge tests show that TiO₂/C microspheres delivered a good rate capability of 106.1mAhg${}^{-1}$ at the high current density of 5Ag${}^{-1}$ and an enhanced cyclic capacity. The superior electrochemical performance could be ascribed to the porous micro–nano structure, smaller crystal size and increased conductivity. The synthesis of TiO₂/C microspheres is easy to scale up for satisfying high-performance sodium storage.

Monoclinic Li₃V₂(PO₄)₃ is a promising cathode material for lithium–ion batteries due to its safety performance and high theoretical capacity. However, the efficient and large-scale preparation of stable composite remains a challenge. Herein, spherical Li₃V₂(PO₄)₃/C and 2LiVPO₄F⋅Li ₃V₂(PO₄) ₃/C cathode materials were prepared by an efficient spray drying method. The structure and morphology of the as-prepared cathode were studied via X-ray diffraction and scanning electron microscopy. Li₃V₂(PO₄)₃/C synthesized at 750°C for 8 h shows the best crystallinity and uniform ball diameter distribution. Based on the optimized conditions, 2LiVPO₄F⋅Li₃ V₂(PO₄)₃/C was also successfully prepared in the same way. Electrochemical results indicate that Li₃V₂(PO₄)₃/C exhibits a superior initial discharge-specific capacity of 143.6 mAh⋅g${}^{-1}$at 0.1 C rate in the range of 3.0–4.5 V, corresponding to a capacity decay rate of 2.79% after 50 cycles. The multi-voltage platform of 2LiVPO ₄F⋅Li₃V₂(PO₄)₃/C has the advantage of high energy density. The good electrochemical performance reveals that spray drying was a promising approach to prepare monoclinic Li₃V₂(PO₄)₃ series cathode materials.

This paper presents an experimental study on preparation of gram-negative bacteria microcapsules by spray drying. Effects of operating conditions on the bacteria survival rate were examined by single factor analysis. Through orthogonal experiment, appropriate conditions were determined as 160°C of the inlet air temperature, 12.5 ml/min of the feed flow rate, 1:9 of the ratio of gum arabic to maltodextrin and 50 ml for fluid nutrient medium with the bacteria. The bacteria survival rate reaches 84.57 %. Examination of storage performance shows that quantity of the viable gram-negative bacteria was increased by 148 % after preserving in plastic film bag for 6 months under ambient temperature from 18°C to 30°C, viability of the bacteria were improved compared to those inoculated from laboratory.

Simulations of crystallisation behaviour in a spray dryer have been performed using a model developed by previous workers applied to a Buchi-290 laboratory scale drier. This simulation provided information on the material properties, such as glass transition changes during the drying process. The potential crystallisation behaviour has been modeled using Williams-Landel-Ferry kinetics. Explorations the model have suggested that the air inlet temperature is an important variable affecting crystallisation in the dryer. The explorations provided drying conditions that permitted reasonable drying while controlling the degree of crystallisation. These conditions were examined and tested experimentally, also showing that the apparent degree of crystallinity was affected by the inlet air temperature.

The potential therapeutic value of bromelain is due to its biochemical and pharmacological properties and hence, it is desired to obtain bromelain in its highest purified form. Crude bromelain extract can be obtained from the fruit of Ananas comosus using ion exchange chromatography. Bromelain thus obtained can be subjected to either spray or freeze drying. The resulting residual activity and the specific activity were compared between the spray and freeze dried powders. Freeze dried bromelain was found to posses the specific activity twice as compared to the spray dried powder. The effect of protective agents and the bulking agents on the retention of activity was studied in both spray as well as freeze drying. The initial results have been encouraging as 90 % of the bromelain recovery was possible.

This investigation made use of the precipitation reaction between calcium hydroxide and orthophosphoric acid to produce a stoichoimetric hydroxyapatite (HA) slurry, which was then spray-dried to form hydroxyapatite powders. Different reaction temperatures (22, 27, 40, 60 and 75°C) and reactant concentrations (0.5, 1.0 and 1.5M) were used to study their influences on the thermostability of the spray-dried HA powders. All slurries were spray-dried at 200°C and with a feeding rate of 2.5 liters per hour. HA discs were made by cold uniaxial pressing at a pressure of 20 MPa. They were subsequently sintered to compare their thermostability with that of HA powders. X-ray diffraction patterns of HA powders and discs sintered at temperatures between 600-1400°C were analyzed. Lattice parameters of HA powders produced under different reactant concentrations were measured to investigate the controlling factors of HA thermostability. Experimental results showed that, for HA powder, lower reactant concentration and higher reaction temperature resulted in higher thermostability. Powders produced under 0.5M and at 60°C could withstand a temperature of up to 1350°C, at which the apatite structure was still the dominant phase. On the contrary, powders produced at other parameters decomposed at lower temperatures. Powders produced under 1.5M and at 40°C started decomposing at 700°C and fully decomposed at 900°C. The decomposition products of all HA powders were initially β-TCP and finally α-TCP only. This result was further verified by the thermostability of the sintered HA discs, which demonstrated the same thermostability as the spray-dried HA powders. Lattice parameters measurement indicated that low reactant concentrations resulted in smaller lattice parameters. The smaller the lattice parameters, the higher the thermostability.

MF@ SiO²/TiO²/ cupric salt core-shell spheres were prepared through a spray drying synthesis using melamine formaldehyde (MF) microspheres as hard templates, and the mixture of SiO² colloid, TiO² colloid and cupric salt as shell precursors. After the calcination of the MF@ SiO²/TiO²/ cupric salt core-shell spheres above at elevated temperatures under nitrogen atmospheres and under air atmospheres respectively, and then carbon-sphere@SiO²/TiO²/Cu core-shell composites (denoted as C-SC) and SiO²/TiO²/CuO hollow spheres (denoted as HS) were obtained. SEM, TEM, XRD and nitrogen adsorption-desorption measurements techniques were utilized to characterize the morphology, structure, component, the surface area and pore size distribution of the resultant core-shell composites and hollow spheres. Results showed that SiO²/TiO²/CuO hollow spheres with cavity structure possess more perfect regularity and uniform structure than rattle-type carbon-sphere @SiO²/TiO²/Cu core-shell composites.