Components of co-continuous phase can form an interpenetrating network structure, which has great potential to synergistically improve the mechanical properties of the blends, and to impart the functional blends superior electrical conductivity and permeability. In this work, the effects of shear rates (50–5000 s?1) at different temperatures on the phase morphology, phase size and lamellar crystallites of biodegradable co-continuous polybutylene terephthalate (PBAT)/polybutylene succinate (PBS) blend are quantitatively investigated. The results show that the above features of the PBAT/PBS have a strong dependence on the shear flow and thermal field. The co-continuous phase of the blend is well maintained at 130 °C. Interestingly, this phase structure transforms into a “sea-island” structure at 160 °C, which gradually recovers to a co-continuous phase when the shear rate increases from 1000 s?1 to 5000 s?1. The phase size decreases with the increase of shear rate both at 130 °C and 160 °C due to the refinement and deformation of phase structures caused by strong shear stress. Unexpectedly, a unique phenomenon is observed that the shear-induced lamellar crystallites are oriented perpendicular to shear direction in the range of 500–5000 s?1 at 130 °C, while the orientation of lamellar crystallites at 160 °C is along the shear direction within the whole range of shear rates. The degree of orientation for the PBAT/PBS blend crystals increases first and then decreases at both temperatures above. In addition, the range of shear rate has reached the level in the industrial processing. Therefore, this work has important guiding significance for the regulation of the co-continuous phase structure and the performance for the blend in the practical processing.
In order to investigate the influence of mixed liquor inorganic suspended solids (MLISS) on membrane flux at different ratio of sludge retention time (SRT) to hydraulic retention time (HRT) in a submerged membrane bioreactor (SMBR), a pilot scale test was conducted for 452 days using traditional Chinese medicine (TCM) wastewater as influent. SRT/HRT was controlled at 150, 480 and 750, respectively. The experimental results showed that the average values of MLISS were 1271.9, 1664.5 and 6898.8 mg/L at different SRT/HRT, respectively; MLISS were accumulated from 265.5 g/h to 4912.93 g/h, which indicated that SMBR could not steadily operate for a long period without sludge withdrawal. Sludge oxygen utilized rate (SOUR) decreased from 5.115 to 1.292 mgO2/(gVSS h) and volume oxygen utilized rate (VOUR) increased from 10.84 to 18.13 mgO2/(L h). Model of membrane flux and MLISS were developed under different temperature and operational pressure by regressions, which were then satisfactorily employed to predict the trend of membrane flux during the experiment. 相似文献
Triplet diradicals have attracted tremendous attention due to their promising application in organic spintronics, organic magnets and spin filters. However, very few examples of triplet diradicals with singlet–triplet energy gaps (ΔEST) over 0.59 kcal mol−1 (298 K) have been reported to date. In this work, we first proved that the dianion of 2,7-di-tert-butyl-pyrene-4,5,9,10-tetraone (2,7-tBu2-PTO) was a triplet ground state diradical in the magnesium complex 1 with a singlet–triplet energy gap ΔEST = 0.94 kcal mol−1 (473 K). This is a rare example of stable diradicals with singlet–triplet energy gaps exceeding the thermal energy at room temperature (298 K). Moreover, the iron analog 2 containing the 2,7-tBu2-PTO diradical dianion was isolated, which was the first single-molecule magnet bridged by a diradical dianion. When 2 was doubly reduced to the dianion salt 2K2, single-molecule magnetism was switched off, highlighting the importance of diradicals in single-molecule magnetism.We report a triplet diradical dianion in magnesium complex with ΔEST = 0.94 kcal mol−1 (473 K). Its iron analog is the first single-molecule magnet bridged by a diradical dianion, and the SMM property is switched off through two-electron reduction.相似文献
采用改进的共沉淀-高温固相法制备了形貌可控的高电压LiNi0.5Mn1.5O4材料。利用锂盐中结晶水易脱水的特点设计了低温高压反应环境。在高温煅烧之前增加反应釜预反应过程,有效提高锂盐与氧化物前驱体的混合均匀性以及反应性,抑制了杂相生成,降低了材料金属离子混排度。调控预反应温度实现了LiNi0.5Mn1.5O4材料形貌和颗粒尺寸的可控制备。研究表明,经过180℃预反应过程合成的样品具有规则的八面体单晶形貌,尺寸分布相对均匀,有效抑制了电极/电解液界面反应,使得合成的材料表现出优异的循环稳定性和倍率性能。常温1C下循环400次后容量保持率达到95.3%,且在20C下仍能放出120.9 m Ah·g-1的比容量。 相似文献
In this paper, a mononuclear Co(II) compound [Co(H2O)6]Cl2·2C6H12N4·4H2O ( 1 ) was synthesized and characterized. X-ray single crystal diffraction analyses shows that the Co(II) ion adopts almost perfect octahedral coordination geometry with O6 donors provided by six water molecules. Magnetic properties studies show it has strong in-plane anisotropy with D = +66.7 cm−1. AC susceptibility measurements indicate it is a field-induced SMM with Ueff = 56.11 K via Raman relaxation process and/or direct process. It is rare for Co(II) ion in cobalt-based compound showing almost perfect octahedral coordination geometry. 相似文献