No abstract

Pickering emulsions stabilized by polysaccharide–polysaccharide complexes are attractive in many applications. However, how interface films formed by soft particles affect the stability of Pickering emulsions has not been well explored. Herein, we designed aggregation-induced emission (AIE)-active modified alginate (Alg-AIE)/chitosan (CS) polyelectrolyte complex (Alg-AIE/CS complex) colloidal particles that are used to stabilize Pickering emulsions. To explore the relationship between the interface film structure and emulsification properties, the microstructure of emulsions was directly visualized by a combination of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The wetting properties of Alg-AIE/CS complexes were regulated by changing the amount of CS, which further regulated the aggregation behavior of the interface. The interfacial adsorption behavior of the particles and the physical stability of the emulsions were determined by combining stability analysis and employing a quartz crystal microbalance with dissipation monitoring (QCM-D). The results showed that the addition of CS resulted in more Alg-AIE/CS complexes that could be adsorbed at the oil–water interface, forming thicker and stronger viscoelastic interface films, which improved the stability of the emulsion. Most importantly, in situ visualization technology provided a new way to understand the interfacial properties of Pickering emulsions.

The development of an eco-friendly nanopesticide formulation can alleviate the problems of low pesticide utilization and environmental pollution. However, the development of green nanopesticide carriers with ideal physical properties and specific bioavailability is still a challenging task at present. In this study, we propose a novel binary additive pesticide carrier system that is a functional polysaccharide-based polymer/surfactant (Alg-DA/APG) to improve the deposition and retention of pesticide droplets. The self-assembled micelle morphology of Alg-DA/APG and its effect on the apparent viscosity were investigated by transmission electron microscopy (TEM) and a Discovery HR-2 rotational rheometer. Surface tension was carried out to investigate the surface activity and critical micelle concentration (CMC) of Alg-DA/APG. The drop impacting experiments exhibited superior antisplash performance of Alg-DA/APG. Furthermore, a binary additive was used as the carrier material and loaded acetamiprid to prepare

A new method for the analysis of cycloserine (4-amino-3-isoxazolidinone, CYC) in rat microdialysis samples has been developed. This method consists of derivatizing the CYC with benzoyl chloride, which transforms primary amines into highly stable derivatives. An attractive feature of this method was that the derivatization reaction is straightforward and can be completed within 10 min. The formed derivative, in contrast to the non-derivatized analyte, exhibited increased chromatographic retention and decreased matrix effects resulting from the co-elution of other components using reversed-phase liquid chromatography and on-line switching. Detection on a quadrupole-linear ion trap mass spectrometer (AB3200 Q-Trap) was performed using electrospray tandem mass spectrometry in multiple reaction monitoring mode. Various derivatization parameters were optimized in order to improve chromatographic separation and minimize ion suppression. In particular, the benzoylation reaction was improved to enhance the reproducibility and sensitivity of the chromatographic method. The transition m/z 207.1 → 105.1 was acquired to monitor the CYC derivatization products. The method was fully validated for its sensitivity, selectivity, matrix effect and stability. A good linearity over the selected range (r > 0.99, range = 22-2200 mg/L), as well as accuracy and precision within ±7% of the target values, was obtained. The assay described herein was successfully applied to quantitatively measure CYC in the lung and blood of anesthetized rats.