Microencapsulation of volatile compounds in fabric care products has brought extra value in a variety of laundrytype applications, allowing clothes to release pleasant scents for weeks after their last wash with minimal amounts of fragrance used. Melamine−formaldehyde is the industry standard in this regard, while polyacrylate and polyurea shells are promising candidates for use in commercial laundry-type applications. Harsh storage conditions and demanding release characteristics have limited the number of viable shell wall materials and chemistries for these kinds of applications. This renders nano-and microencapsulation of volatile compounds for laundry-type applications one of the most challenging areas in the encapsulation field. The largest drawback of the current technology is the limited biodegradability of the produced microcapsules, e.g. when leaking via wastewater. This review summarizes the search toward viable, high-performant and sustainable alternatives for the current technology. First, various techniques to encapsulate volatile compounds in this context are overviewed. Recent relevant encapsulation reports using natural and synthetic shell walls are discussed, while controlled release data are included where possible. Finally, a perspective containing insights toward sustainability in the engineering of alternative capsule chemistries is offered.

Bio-based and degradable polymers such as poly(lactic acid) (PLA), have become prominent. In spite of encouraging features, PLA has a low melt strength and melt elasticity, resulting in processing and...

End-group-functionalized hyperbranched polymers were synthesized to act as a carbon nanotube (CNT) surfactant in aqueous solutions. Variation of the percentage of triphenylmethyl (trityl) functionalization and of the molar mass of the hyperbranched polyglycerol (PG) core resulted in the highest measured surfactant efficiency for a 5000 g/ mol PG with 5.6% of the available hydroxyl end-groups replaced by trityl functions, as shown by UV−vis measurements. Semiempirical model calculations suggest an even higher efficiency for PG5000 with 2.5% functionalization and maximal molecule specific efficiency in general at low degrees of functionalization. Addition of trityl groups increases the surfactant−nanotube interactions in comparison to unfunctionalized PG because of π−π stacking interactions. However, at higher functionalization degrees mutual interactions between trityl groups come into play, decreasing the surfactant efficiency, while lack of water solubility becomes an issue at very high functionalization degrees. Low molar mass surfactants are less efficient compared to higher molar mass species most likely because the higher bulkiness of the latter allows for a better CNT separation and stabilization. The most efficient surfactant studied allowed dispersing 2.85 mg of CNT in 20 mL with as little as 1 mg of surfactant. These dispersions, remaining stable for at least 2 months, were mainly composed of individual CNTs as revealed by electron microscopy.

Thiol (SH) containing additives improve the mechanical properties of rigid, glassy gluten materials. However, the underlying molecular mechanism is still unclear. In particular, the importance of the preceding gluten‐additive mixing conditions remains to be investigated. Here, different additives containing either only SH, only disulfide or both SH and disulfide functionalities were synthesized and their impact on the gluten network using different mixing conditions prior to subsequent molding were assessed. All SH containing additives decreased the gluten molecular weight (MW) during mixing to a degree depending on the conditions. Additives with only disulfide functionality did not significantly affect protein size during mixing irrespective of the conditions used. Only when mixing induced sufficient MW reduction did the strength and failure strain of rigid gluten materials increase. This shows that factors other than the degree of cross‐linking affect the strength of rigid gluten materials. These results support our hypothesis that altered molecular conformations and improved molecular entanglements contribute to material strength. The extent to which such conformational changes occur may depend on the additive and the way of mixing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41160.