Hu Lijun,Qian Zhengxin,Gao Wei,Wang Xiufang,Tian Yong
A one-step soft templating strategy for synthesizing uniform and monodisperse mesoporous carbon nanospheres (UM-MCNs) with sub-100 nm size and large mesopores without using any co-solvent additives has not yet been reported. Herein, an extremely simple,effective and environment friendly strategy was first developed to prepare uniform, monodisperse polymer nanospheres (PNs) and UM-MCNs with small particle size (80–90 nm) and large mesopores (~ 6.8 nm), where F108 with long hydrophilic chains not only served as mesopore-forming reagent, but also as a dispersant reagent that facilitated uniform growth of the nanospheres, resulting in a narrow particle size distribution. Moreover, F108 could also act as a stability-driving agent, that is, the phloroglucinol/formaldehyde polymer was tightly “locked” by the long hydrophilic segments of F108 via strong hydrogen bonding. Consequently, intact carbon nanospheres with large mesopores were obtained after carbonization, and finally a three-dimensional periodic arrangement of the UM-MCNs was formed. In addition, ethanol could be used as a co-surfactant or co-solvent during self-assembly. The present strategy may not only supply a novel avenue to synthesize UM-MCNs, but also shed light on insights into the profound impact of F108 with long hydrophilic chains and ethanol on the morphology and pore size of carbon spheres.
Jianfeng Zhan,Feng He,Shuxian Chen,Abishek Jung Poudel,Ying Yang,Lin Xiao,Fu Xiang,Shiming Li
Essential oils (EOs) have been used in cosmetics and food due to their antimicrobial and antiviral effects. However, the applications of EOs are compromised because of their poor aqueous solubility and high volatility. Qiai (Artemisia argyiLevl. et Van. var.argyicv. Qiai) is a traditional Chinese herb and possesses strong antibacterial activity. Herein, we report an innovative formulation of EO as nanohydrogels, which were prepared through co-assembly of Qiai EO (QEO) and Pluronic F108 (PEG-b-PPG-b-PEG, or PF108) in aqueous solution. QEO was efficiently loaded in the PF108 micelles and formed nanohydrogels by heating the QEO/PF108 mixture solution to 37 °C, by the innate thermo-responsive property of PF108. The encapsulation efficiency and loading capacity of QEO reached 80.2% and 6.8%, respectively. QEO nanohydrogels were more stable than the free QEO with respect to volatilization. Sustained QEO release was achieved at body temperature using the QEO nanohydrogels, with the cumulative release rate reaching 95% in 35 h. In vitro antibacterial test indicated that the QEO nanohydrogels showed stronger antimicrobial activity againstS. aureusandE. colithan the free QEO due to the enhanced stability and sustained-release characteristics. It has been attested that thermo-responsive QEO nanohydrogels have good potential as antibacterial cosmetics.Keywords:essential oil;qiai;nanohydrogel;thermo-responsive property;antibacterial activity
Bo Zhang,Hui Wang,Yiwei Lu,Yang Song,Yanlin Li,Yuanyuan Tian
Fabrication of electrochromic films with micro/nanostructures is one of the most feasible ways to improve their properties for high-performance electrochromic devices (ECDs). In this work, mesoporous TiO 2 and NiO electrochromic films are prepared by sol-gel technique with an auxiliary solvent of F108 (PEO 1 3 2 PPO 5 0 PEO 1 3 2 ). By adjusting the content of F108 and heat treatment temperature, the transparent and uniform mesoporous films are successfully prepared. The TiO 2 and NiO films are composed of inter-connected nanoparticles with a size of about 20 nm. The thicknesses of the films are about 300 nm and the mesoporous sizes are about 13 nm. The films have a short response time during the electrochromic process. When supplied with positive/negative voltages for 50 s, the coloring/bleaching times of TiO 2 and NiO mesoporous films are 15/13 and 17/12 s, respectively. The ECD fabricated with TiO 2 and NiO mesoporous films shows good electrochromic properties: short response time (14/19 s, for bleaching/coloring time), wide transmittance modulation range ( ∼ 37.21% at 540 nm), high coloration efficiency (CE) (100.6 cm 2 /C at 540 nm) and outstanding cycle stability (800 cycles). These are attributed to the mesoporous channels of films, which can increase reaction activity site, shorten ions transport path, and thus improve electrochromic reaction.
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