Volatility is an inherent fragrance attribute and typically implies a reduced perception over time. One possibility to elongate odor perception is utilizing controlled fragrance-delivery systems. Herein, the Y type of faujasite with different extra-framework cations (abbreviated as ZY, where Z represents Na⁺, Ca²⁺, or La³⁺) was examined as potential carriers for fragrance entrapment and delivery. d-Limonene (Lim) and linalool (Lol) as model fragrances were loaded in the pore space of Y zeolites, yielding composites [email protected] (FG = Lim, Lol). It was found that the fragrance release profiles correlate highly with the cationic species located in the nonframework. The retention of fragrances in matrices increases in the order NaY < CaY < LaY for either limonene or linalool. Interestingly, the release rate of limonene was significantly slower than that of linalool when encapsulated in the same zeolite, although neat limonene has a much higher saturated vapor pressure than linalool. For instance, the total fraction of aroma released from [email protected] over 30 days was about 10%, while the value was ∼20% for [email protected] Based on the density functional theory calculations, the above results could be well rationalized by the electrostatic attraction and shape selectivity of microporous matrices to the dopant molecules.

A new kind of hydrophilic copolymer poly(HEMA-co-VNP) was designed and synthesized by the radical copolymerization of 2-hydroxyethylmethacrylate (HEMA) and 2-{[2-(4-vinylbenzyloxy)naphthalen-1-yl]methyleneamino}-(S)-2-phenylethanol (VNP). The desired copolymer showed a highly selective red-shifted emission and a unique chiroptical response upon HSO₄ ⁻ binding in organic solution. UV-vis and ¹H NMR spectroscopic studies revealed that the hydrogen bonding between the imine moiety in the VNP repeating units and HSO₄ ⁻ is crucial for the high selectivity of the receptor to this anion. As expected, the incorporation of HEMA into the polymer matrix endowed the copolymer excellent hydrophilicity, flexibility and good film-forming properties. Thus, high-quality film sensors could be easily fabricated on quartz plates through spin-casting techniques. The resultant polymeric films can recognize HSO₄ ⁻ ions among a series of common anions in aqueous solution with high selectivity and sensitivity. The promising new film probe for HSO₄ ⁻ has distinct characteristics such as a rapid response, enough stability in an aqueous media and practicality.

The cationic ring-opening polymerization (CROP) of substituted 2-oxazolines using rare-earth metal triflates (RE(OTf)₃) as initiator was investigated for the first time. In this work, we examined the polymerization characteristics of 2-ethyl-2-oxazoline (EtOx) initiated by Sc(OTf)₃ under conventional thermal heating and microwave irradiation, and compared the respective outcomes with those obtained with the most frequently used initiator methyl tosylate (MeOTs). The results indicated that Sc(OTf)₃ exhibits a higher catalytic efficiency to the EtOx polymerization than MeOTs under identical conditions. The controlled/living nature of the Sc(OTf)₃-catalyzed CROP was confirmed by its linear first-order kinetics and the narrow molecular weight distribution of the resultant polymers as well as the block copolymerization of EtOx and 2-phenyl-2-oxazoline (PhOx). Based on in situ NMR spectroscopic studies and SEC analysis of PEtOx samples obtained from the control termination experiments, a possible initiating/propagating mechanism has been proposed for the living cationic ring-opening polymerization. Morever, this rare-earth catalytic system can also be applied to the ring-opening polymerization of some sterically hindered or aryl-substituted 2-oxazolines.