Nanoencapsulation of curcumin in polyurethane and polyurea shells by an emulsion diffusion method

Preparation and characteristics of nanocapsules containing essential oil for textile application

“…As seen in the Figure 3c, the multiple absorption peaks at 2930-2859 cm -1 were assigned to an aliphatic C-H stretching vibration, the absorption peaks at 1728 and 1115 cm -1 were associated with -C=O stretching and -C-O stretching of the MMA, respectively. [36] The absorption peaks at 1600, 1581 and 1492 cm -1 were associated with benzene ring C=C stretching vibration, and the absorption peaks at 751 and 700 cm -1 were associated with benzene ring deformation vibration of St. [37] All the above characteristic peaks of P(St-co-MMA) could be observed in the FT-IR spectrum of the aromatic nanocapsules (Figure 3a). Furthermore, the obvious absorption peaks at 3450 cm -1 and 1678 cm -1…”

Preparation and Characterization of Polyurethane Nanocapsules Containing Cassia alata Linn. Extract

“…Encapsulation yield, which obtained from dilution time of the 6 hour experiment, was less than other experiments. It might be due to CO 2 that generated from the hydrolysis of isocyanate at a long dilution time may be higher than CO 2 that generated from short dilution time, contribute to a less compact structure formation and increase the porosity of the capsules [10]- [13]. …”

“…The reaction between isocyanate and BDO is lower than isocyanate and emulsifier. The consumption of emulsifier during shell formation results in the drop instability, therefore they tend to merge to larger size [10]. Moreover, it can be related to the agglomeration of small size nanocapsules which resulted in larger size of nanocapsule.…”

“…Nanocapsules were prepared using an emulsion diffusion method [10]. This method can be categorized into four steps, i.e.…”

“…1. For dilution step, the large quantity of distilled water was added during this step to allow diffusion of ethyl acetate from the internal phase to external phase, and then leads to the formation of nanocapsules [10]- [13]. Fig.…”