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Aluminum-substituted M-type strontium hexaferrite (SrM-Al, SrFe12−xAlxO19, 0 ≤ x ≤ 4) with uniform microstructure and excellent magnetic properties was synthesized by conventional ceramic processing based on solid state reaction. Coercive field was highly enhanced by heavy doping with Al3+ although magnetization was significantly reduced. However, formation of coarse microstructure and poor development of Hc with low level doping of Al3+ disturbed practical application. To promote phase formation and to suppress growth of coarse grains which were induced by incorporation of Al3+ ions, SrM-Al ceramics was processed with NaOH. Such Na-assisted processing of SrM-Al reduced formation of non-magnetic phases and assisted development of uniform fine grains. In addition, the large residual strain by Al3+ doping was partially relieved by the same approach. As a result, saturation magnetization of SrFe12−xAlxO19 was remarkably enhanced and the BHmax of randomly oriented hard magnetic ceramics was improved to 1.23MGOe by concomitant addition of Na and Al ions.

We studied the structural and magnetic properties of BaFe

Scale-up of synthesis process is highly required for commercial application of quantum dots (QDs). Although batch-type hot injection method is most popular synthesis route for QDs, its commercial scale-up version only gives non-uniform and less luminescent QDs with broad size distribution. In this study, we introduce a novel and facile method of large-scale synthesis of QDs using a fluid-dynamically controlled reactor, Taylor-Couette reactor (TCR). We successfully synthesized CdSe QDs with TCR and as-synthesized QDs were capped with epitaxial CdS layers using the molecular precursors for enhanced luminescence. The synthesis process was stabilized after 20 min from the start of initial injection of precursors and standard deviation of luminescence wavelength and spectral linewidth was less than 1 nm. After shell capping process based on pyrolysis of Cd-diethyldithiocarbamate, CdSe QDs synthesized from continuous processing route based on TCR showed intense photoluminescence at 640 nm with a spectral linewidth of 33 nm, which is much narrower than PL spectra of QDs synthesized from conventional batch-type synthesis route using reaction vessel with large volume capacity. We demonstrated high throughput synthesis of highly luminescent CdSe QDs using TCR as a platform for continuous synthesis with very large production yield (22,560 kg‧day−1‧m−3 in space-time yield).

The drawbacks of conventional drug administration include repeated administration, non-specific biodistribution in the body's systems, the long-term unsustainability of drug molecules, and high global cytotoxicity, posing a challenge for the efficient treatment of chronic diseases that require varying drug dosages over time for optimal therapeutic efficacy. Most controlled-release methods encapsulate drug molecules in biodegradable materials that dissolve over time to release the drug, making it difficult to deliver drugs on a schedule. To address these limitations, we developed a magneto-, opto-stimuli responsive drug delivery system based on functionalized electrospun nanofibers loaded with superparamagnetic iron oxide nanoparticles (SPIONs). We exploited the Neel relaxation effect of SPIONs, where heat generated from vibrating SPIONs under exogenously applied magnetic fields or laser illumination induced structural changes of the thermo-sensitive nanofibers that encapsulate the particles. We showed that this structural change of nanofibers is the governing factor in controlling the release of dye molecules, used as a model drug and co-encapsulated within the nanofibers. We also showed that the degree of nanofiber structural change depends on SPION loading and duration of stimulation, demonstrating the tunability of the drug release profile. Overall, we demonstrated the potential of SPION-embedded thermoplastic nanofibers as an attractive platform for on-demand drug delivery.

We developed linearly linked spherical fillers in polymer composites with incorporating Al2O3-Fe3O4 hybrid particles under a magnetic field to form thermal networks for high thermal conductivity. The Al2O3-Fe3O4 hybrid particles were prepared by a simple precipitation method and their magnetic properties were characterized with magnetic hysteresis. The Al2O3-Fe3O4 hybrid particles were well aligned through direction of magnetic field as confirmed by microscopic observation. The polymer composites obtained with Al2O3-Fe3O4 hybrid particles possessed high thermal conductivity in a parallel magnetic alignment direction at low filler loading, which is more than 240% outperformed the composites with randomly dispersed fillers.

Efficient heat transport along through-plane direction is one of the primary requisites for thermal interface materials (TIMs) to relieve heat accumulation at the interface between chip and heat sinks. We report enhanced thermal conduction of Al 2 O 3 -based polymer composites by surface wetting and texturing of thermally conductive hexagonal boron nitride (h-BN) nanoplatelets with large anisotropy (diameter 2 O 3 macrobeads and surface modified h-BN nanoplatelets. Here, the clustering or assembly of h-BN nanoplatelets is analyzed based on depletion interaction of colloidal particles. In addition, further addition of minimal amount of SiO 2 nanoparticles shows a drastic improvement of thermal transport properties, which is attributed to the depletion interaction between nanoplatelets mediated by spherical nanoparticles. Here, the benefits of surface wetting for thermal management composite materials are illustrated.

Highly luminescent boron nitride (BN) was synthesized by pyrolysis of molecular adduct prepared by chemical mixing of boric acid and melamine with a small amount of cerium nitrate. After pyrolysis, Ce ions were substitutionally incorporated to B3N3 hexagonal layer of turbostratic BN at a very low doping level which was estimated to be less than 7 × 1018 atoms/cm3. Ordered stacking of hexagonal layers along c-axis of BN or transformation of turbostratic BN to hexagonal BN was induced by addition of Ce ions even though the amount of Ce ions surpassed substitutional doping limits. The intense photoluminescence (PL) spectrum of Ce-doped BN was detected at 390 nm by excitation of UV light (λ = 314 nm) and PL intensity was improved with increasing level of Ce addition following the enhanced crystallinity of turbostratic BN. The origin of UV-emission was ascribed to the transition from the crystal field components of the 5d level to the 4f ground states of the Ce3+ ion.

We report carbon-coated porous silica macroparticles (SiO 2 @C) prepared using polymeric templates and subsequent carbonization with sucrose for improved electrochemical energy storage in lithium-ion batteries (LIBs). In addition, boron is introduced to improve the stability of electrochemical cells by pyrolyzing mixtures of sucrose and boric acid (SiO 2 @C + B) under inert atmosphere. The initially large surface area of porous SiO 2 (S BET ∼ 658 m 2 g −1 ) is reduced to 102 m 2 g −1 after carbonization and introduction of boric acid. Surface of both SiO 2 @C and SiO 2 @C + B are covered with amorphous carbon. In particular, SiO 2 @C + B particles containing borosilicate (Si–O–B) phase and B–O bondings and Si–C–O bondings are also detected from the X-ray photoelectron spectra. The SiO 2 @C + B macroparticles shows high reversible charge capacity up to 503 mAh g −1 after 103 cycles of Li intercalation/de-intercalation although initial capacity was 200 mAh g −1 . The improved charge capacity of SiO 2 @C + B is attributed to formation of advantageous microstructures induced from boric acid.

We have synthesized quantum dot (QD)-embedded inorganic nanocomposites by effective combination of spray pyrolysis and subsequent sol–gel processing. The rapid depression of emission intensity of QDs just after addition of ammonia for sol–gel processing was effectively retarded by intermediate addition of boron alkoxide to the self-assembled QD ensembles. White-light-emitting diodes with low color correlated temperature were fabricated by combining QD-inorganic nanocomposite particles and conventional oxide. In contrast to previous reports describing fabrication of wLED by simple blending of bare quantum dots with silicone encapsulants, QD-embedded in B 2 O 3 –SiO 2 -based nanocomposite particles provide much enhanced stability of light emission during the prolonged operation.

The properties of magnetic material of Nd-Fe-B are highly affected by various factors such as particle size, magnetic anisotropy, phase purity and crystal structure. Incorporation of excess neodymium was carried out in various percentages so that it will adjust the proportion of neodymium in the host crystal after reduction treatment and finally help to improve magnetic property of a material. The interdiffusion of Nd-Fe and boron was studied for various compositions and their effect on magnetic property was understood with theoretical concepts. The factors such as amount of hard and soft phase in the reduction treated product is also responsible for the possible exchange coupling between hard and soft phase magnets for better magnetic properties.

A halophilic, aerobic bacterium, designated PO-M2T, was isolated from seashore sand, from Pohang, Korea and characterized on the basis of physiological and biochemical features. Phylogenetic analysis of 16S rRNA gene sequences revealed a clear affiliation of the novel strain with members of the genus Idiomarina. Sequence similarities between strain PO-M2T and the type strains of species belonging to the genus Idiomarina ranged from 94.3 to 95.5 %. Cells of strain PO-M2T were straight or slightly curved rods and formed light-yellow colonies on marine agar medium. The major isoprenoid quinone was ubiquinone (Q-8) and the predominant cellular fatty acids were C15 : 0 iso (19.3 %), C17 : 1 ω9c iso (11.9 %), C17 : 0 iso (10.9 %), C18 : 1 ω7c (10.4 %), C16 : 0 (9.0 %) and C16 : 1 ω7c and/or C15 : 0 iso 2-OH (7.2 %). The G+C content of the DNA was 45.1 mol%. Based on physiological, biochemical and chemotaxonomic traits and comparative 16S rRNA gene sequence analysis, it is demonstrated that the isolate represents a novel species of the genus Idiomarina, for which the name Idiomarina homiensis sp. nov. is proposed. The type strain is PO-M2T (=KACC 11514T=DSM 17923T).

Two bacterial strains were isolated from greenhouse soils of Daejeon and Yangpyeong regions in Korea. The strains, designated GH1-9T and GH19-3T, were Gram-negative and aerobic, with rod-shaped cells. Their DNA G+C contents were 61.7 and 67.3 mol%, respectively. The major fatty acids of strain GH1-9T were iso-C16 : 0, iso-C15 : 0, iso-C14 : 0, iso-C17 : 1 ω9c and iso-C11 : 0 3-OH and the major components of strain GH19-3T were iso-C16 : 0, iso-C15 : 0, C16 : 1 ω7c alcohol, iso-C17 : 1 ω9c and iso-C11 : 0 3-OH. None of the species of the genus Lysobacter with validly published names showed 16S rRNA gene sequence similarity values of more than 97 % with respect to the novel isolates. The closest sequence similarity of strain GH1-9T was with Lysobacter concretionis DSM 16239T (96.4 %), whereas strain GH19-3T showed the highest sequence similarity with Lysobacter enzymogenes DSM 2043T (96.6 %). Polyphasic taxonomic studies indicated that the two strains should be classified as representing novel members of the genus Lysobacter. The names Lysobacter daejeonensis sp. nov. and Lysobacter yangpyeongensis sp. nov. are proposed, with strains GH1-9T (=KACC 11406T=DSM 17634T) and GH19-3T (=KACC 11407T=DSM 17635T), respectively, as the type strains.

The effect of 5, 10, 12, and 15 wt.% excess of Nd on the synthesis and properties of hard phase Nd2Fe14B magnetic materials is investigated.

A Gram-negative, strictly aerobic, non-spore-forming bacterium, motile by means of single polar flagellum and rod-shaped, designated strain GR12-1T, was isolated from soil of a ginseng field in Yeongju region, Korea. Phylogenetic analysis based on 16S rRNA gene sequences indicated that this strain is related to members of the genus Pseudoxanthomonas, showing sequence similarity values ranged from 92.3 to 96.2 %. This organism grew at 5–33 °C, with optimum growth at 28 °C. Strain GR12-1T grew optimally in the presence of 0–2 % NaCl. The whole-cell fatty acid profile included iso-C15 : 0, iso-C17 : 1 ω9c, iso-C16 : 0, iso-C11 : 0 3-OH and iso-C17 : 0 as major components. The only isoprenoid quinone was ubiquinone 8 (Q-8). The DNA G+C content was 63.4 mol%. On the basis of phenotypic, genetic and phylogenetic data, strain GR12-1T should be classified as a member of a novel species of the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas yeongjuensis sp. nov. is proposed, with strain GR12-1T (=KACC 11580T=DSM 18204T) as the type strain.

A novel bacterium, designated strain H3-R18T, was isolated from seashore sand collected from Homi cape, Pohang city, Korea. Cells were Gram-negative, aerobic, non-motile, cream-coloured, mesophilic and slightly halotolerant. 16S rRNA gene sequence analysis indicated that the organism was a member of the genus Pseudomonas, but the sequence showed ⩽96.3 % sequence similarity to that of the type strains of all recognized Pseudomonas species. Highest sequence similarities were to Pseudomonas brenneri CFML 97-391T (96.3 %) and Pseudomonas migulae CIP 105470T (96.3 %). The major fatty acids were summed feature 3 and C16 : 0, with lesser amounts of C12 : 0, C12 : 0 3-OH, C18 : 1ω7c and C14 : 0. The major isoprenoid quinone was Q-9. The DNA G+C content was 64.0 mol%. The phylogenetic, phenotypic and genetic properties of strain H3-R18T suggest that it represents a novel species, for which the name Pseudomonas pohangensis sp. nov. is proposed. The type strain is H3-R18T (=KACC 11517T=DSM 17875T).

Nanophase materials with an average grain size in the range of 1 to 50 nm have attracted research interest for more than a decade since their physical properties are quite different from that of their bulk micron-sized counterparts. The properties of magnetic materials are highly dependent on its particle size. The synthesis of hard phase magnetic nanoparticles was carried out in a one pot reaction. By controlling the reaction conditions, the exchange coupling between the hard and soft phase in the hard/soft nanocomposite magnetic material has been studied. The reaction parameters, such as the ratio of the metallic precursors, reaction temperature and reduction process, play an important role in determining the shape and size of the material along with its magnetic properties. To produce the exchange coupling between hard and soft phases their particle size needs to be controlled very precisely, which can help to increase the interaction between the two phases. By controlling the ratio of precursors, the amount of soft phase of α-Fe was optimized for the synthesis in situ with the hard phase Nd2Fe14B material.