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Abstract Ionic liquids (ILs) containing imidazolium cations have a number of useful properties, such as high permeability to cells, high antimicrobial activity, and good biocompatibility. With the aid of ILs, transdermal delivery, solubilization of poorly soluble drugs were developed and therapeutic effects were improved. In this work, 1‑butyl‑3‑methylimidazolium hexafluorophosphate-incorporated, chitosan-modified, submicron-sized poly(dl ‑lactide‑co‑glycolide) (PLGA) nanoparticles (NPs) were prepared using the emulsion solvent diffusion method for the treatment of biofilm infections. Prepared IL-incorporated PLGA NPs using surfactants such as Tween-80 and poloxamer-188 showed a high antibacterial activity to the bacterial cells under the biofilm. Additionally, antibacterial mechanism of IL-incorporated PLGA NPs was revealed by annular dark field scanning transmission electron microscopy combined a simple sample pretreatment method. We established a drug delivery system using IL-incorporated PLGA NPs to enhance the potential of polymeric nanocarriers for treating biofilm infections. Graphical abstract Unlabelled Image Highlights • Ionic liquid-incorporated polymeric particles for treating biofilm infections was optimized. • Particles presented strong antibacterial activity in biofilms by using surfactant. • Particles exerted antibacterial activity while maintaining liquid phase. • Therapeutic polymeric particles could be effective for biofilm infections by new routes. [ABSTRACT FROM AUTHOR]

The influence of water molecules on ionic liquid (IL; 1-butyl-3-methylimidazolium tetrafluoroborate) intercalated montmorillonite (M IL ) and the selectivity of IL have been studied. The intercalation behavior of IL into an IL-intercalation compound containing various amounts of water (M ILW ) was investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and a selected area electron diffraction pattern (SAED). The structural change of M IL influenced by the water was also confirmed by a TEM study. Based on the amount of interlayer exchangeable cations as measured by inductively coupled plasma (ICP), the extent of the intercalation and arrangement of cations in the interlayers of M IL treated by different amounts of water was studied. In addition, the Raman spectroscopy results showed that the water molecules do not interact with both the IL and the montmorillonite. These results suggest that the IL-intercalation compound can maintain its property in water due to its high water resistance. Moreover, this technique would be useful for the adsorption reaction and fabrication of montmorillonite composite materials using non-polar organic molecules. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, we investigated the direct intercalation of three kinds of ionic liquids (ILs) of different salts (imidazolium and ammonium) and cation sizes into montmorillonite (M) clay, and successfully fabricated the IL intercalated montmorillonite (MIL ) compounds. The peak shifts of the MIL intercalated compounds in comparison with dried montmorillonite powder as observed by XRD results showed that crystal swelling was significantly influenced by the cation sizes of the ILs. The intercalation behaviors of the MIL compounds were also compared by TEM and the results are in good agreement with the XRD. The TEM–EDS results further confirmed the intercalation of three types of ILs into the montmorillonite. Based on the cation exchange capacity as measured by ICP and mathematical calculations, the extent of the intercalation and arrangement of cations in the interlayers of the montmorillonite are proposed. The TG-DTA results showed an improved thermal stability of all three kinds of MIL intercalated compounds, and the XRD indicated that the remaining IL initiates a carbonization process with the montmorillonite at 1000°C. Furthermore, the AC impedance results of the MIL compounds showed an ionic conductivity. These results suggest the possible application of the MIL intercalated compounds in electrical conductive films, solar cells, fuel cells, etc. [Copyright &y& Elsevier]

Abstract: The purpose of this study is to develop a simple method to observe the surface morphology of non-conductive material in its hydrated condition. Here porous hydroxyapatite (HAp) green body prepared by gelcasting process was considered as a case study, and, the resultant body was subsequently treated with hydrophilic ionic liquid (IL). The surface morphology and the pore structure of the IL-treated porous HAp green body were successfully observed even in hydrated condition without any charging using field emission scanning electron microscope (FE-SEM). Results showed that the pore diameter from 300 to 600μm in as-prepared green body was reduced to 100–300μm in the sample sintered at 1000°C. Raman results showed that the IL forms weak hydrogen bond with water molecules within the sample and, that prevents from drying in vacuum condition. In addition, the IL acts as a conducting media for HAp ceramics to be observed under FE-SEM. [Copyright &y& Elsevier]

Abstract: In this study, a simple and convenient method for observing the surface morphology of hydrated porous ceramic green bodies is proposed. The porous hyrdoxyapatite (HAp) green body was prepared by a gelcasting process and was dried in a humid chamber from 90 to 50% relative humidity at 25°C before subsequent treatment with a hydrophilic ionic liquid (IL). The surface morphology of the IL-treated porous HAp green body was observed using FE-SEM. The results showed that the pore morphology and microstructure of the HAp green body was readily observable without evidence of charging. The as-prepared sample showed pores approximately 300–600μm in diameter, which gradually contracted to approximately 200–400μm upon drying in the humid chamber. Following sintering at 1000°C, the pores had further contracted to approximately 100–300μm. The IL binds with the surrounding water to prevent the sample from drying in vacuum and acts as a conductive media, allowing the HAp ceramics to be observed in the electron microscope. In comparison to the micro-focused X-ray CT analysis, the fine pore structure (less than 100μm) could only be observed using FE-SEM when the porous body had also been subjected to the IL treatment. [Copyright &y& Elsevier]