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Optoelectronic functional composite materials with porous structures are of great importance in various fields. A hybrid composite (SnP@SiA) composed of (trans-dihydroxo)(5,10,15,20-tetraphenylporphyrinato)tin(IV) (SnP) in silica aerogel (SiA) was successfully fabricated through the reaction of SnP with silanol groups of SiA in the presence of hexamethyldisilazane (HMDS). SnP@SiA was then characterized using various instrumental techniques. The zeta potential for SnP@SiA (−11.62 mV) was found to be less negative than that for SiA (−18.26 mV), indicating that the surface of SnP@SiA is covered by hydrophobic species such as SnP and trimethylsilyl groups. The Brunauer–Emmett–Teller (BET) surface area, pore volume, and average pore size of SnP@SiA are 697.07 m2/g, 1.69 cm3/g, and 8.45 nm, respectively, making it a suitable composite for catalytic applications. SnP@SiA, a photocatalyst with high porosity and a large surface area, yields promising performance in the photodegradation of acid orange 7 (AO7) under visible light irradiation in aqueous solution. This hybrid composite exhibited the desirable properties of aerogels along with the photoelectronic features of porphyrins. Therefore, this porphyrin-imbedded mesoporous material has valuable potential in various applications such as photocatalysis, light energy conversion, biochemical sensors, and gas storage. [ABSTRACT FROM AUTHOR]

SUMMARY: Sediment loading by human activities has increased in recent years and sedimentation in coastal areas is problematic because it removes seaweed forests. In this study, we examined the effects of different sediment quantities (0, 2, 4, and 6 mg cm−2) and particles sizes (<100, 100–250, and 250–600 μm) on zygote attachment, and germling survival and growth of Sargassum thunbergii, an economically and ecologically important species. Zygote attachment was negatively correlated with increased sediment quantities. However, it was not significantly different among sediment particle sizes. In addition, survival and growth of germlings were significantly inhibited by increased sediment quantity. Smaller particle size (< 100 μm) had greater negative impact on the survival and growth than bigger ones. Results of the present study suggest that early development of S. thunbergii is significantly inhibited by sediment. This might be a vital factor that results in forest depletion in Korea. [ABSTRACT FROM AUTHOR]

Seo, J.O.; Park, H.S., and Kim, N.G., 2023. Effects of temperature, photo irradiance and photoperiods on the early growth of Sargassum thunbergii. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 563-567. Charlotte (North Carolina), ISSN 0749-0208. This study investigated the effects of temperature and light on the germination rate and growth of embryos obtained from mature Sargassum thunbergii, and early embryo development. The Sargassum thunbergii used in the experiment was collected in June 2022 from the Tongyeong coast, Gyeongnam, Korea. The released embryos were cultured at 10-25°C, a light intensity of 40 and 80 µmol m-2s-1, and a 14L:10D photoperiod (light: dark). The rhizome development and elongation of the germinated Sargassum thunbergii thallus occurred at weeks 1 to 3 of culture. Serrated secondary leaves formed in week 4 of culture, and fourth leaves formed in 5 weeks. At 6–10 weeks, many scale-like leaves developed. The germination rate of Sargassum thunbergii embryos was maximal at 25°C and 80 µmol m-2s-1 and lowest at 10°C and 40 µmol m-2s-1. The growth characteristics of the germinated thallus of this species differed more depending on the temperature, which makes Sargassum thunbergii a photophilic eurythermal seaweed that grows well under large temperature variation. [ABSTRACT FROM AUTHOR]

The life cycle of two dioecious species, Porphyra dentata and P. pseudolinearis, from Korea was completed in the laboratory. Conchocelis filaments were cultured at temperatures of 5-30 deg. C with a photonirradiance of 10-80 Mumol m-2 s-1under a photoperiod of 14L:10D. In both species, the fastest growth of the conchocelis was observed at 20 deg. C and 40 Mumol m-2 s-1, and conchosporangial branches were produced at 10-25 deg. C and 10-80 Mumol m-2 s-1. Foliose thalli of both species were cultured at 5-30 deg. C, an irradiance of 40 Mumol m-2 s-1 and a photoperiod of 10L:14D. The best growth of P. dentata and P. pseudolinearis was at 10-15 deg. C and 5 deg. C, respectively. Archeospores were not formed on either, under any culture condition. Zygotospores of both species were released at 15 deg. C. They germinated to form t he filamentous conchocelis. Neither monospores nor protothalli were produced by the conchocelis of eitherspecies in culture. For both species, growth and maturation of the two phases were influenced more by temperature than by irradiance. [ABSTRACT FROM AUTHOR]