This result was surprising since based on the intuitionistic knowledge of their chemical structure and the interaction energy calculation Figure 4 , it is anticipated that limonene should escape more quickly than the latter. Furthermore, it has been reported that the confined nanochannels of zeolites would enhance the intermolecular hydrogen-bond interactions of alcohol compounds, 54 which also contributes to their retention in the matrix.
The observation that limonene was better retained within zeolites than linalool may be rationalized from the match between the size and shape of the FAU framework and the sorbate molecules. From the electrostatic potential ESP distribution of the two fragrant molecules plotted in Figure 6 , limonene shows an overall smaller geometry size relative to linalool, with the kinetic diameters of 9. This suggests that both can access the faujasite supercage through its 7. However, the sodalite cage does not allow a sufficiently large space for linalool molecules because its pore diameter On the contrary, it can be expected from limonene to occupy the sodalite cage through a hexagonal window diameter of 6.
The speculation is supported by the fact that Y-type zeolites were loaded with more limonene and the resulting composite [email protected] had higher thermal stability than their corresponding counterparts [email protected] Figure 2 B—E.
This also means that the limonene molecules confined in sodalite cages would have a longer diffusion path to be passed and therefore release more slowly compared to linalool. Similar size or shape selectivity has also been found in the adsorption and catalytic systems based on MOF and zeolite microporous materials. We utilized the Y-type FAU zeolites to construct fragrance-delivery systems with limonene and linalool as model perfume compounds. Experimental and computational results have demonstrated a specific contribution of the extra-framework cationic species to aroma retention and release kinetics.
The fragrance release mechanism from the NaY matrix is a Fickian diffusion, while for CaY- and LaY-based carriers, the aroma transport obeys zero-order kinetics. Also, limonene was found to be entrapped more efficiently in a given zeolite compared with linalool and the aroma evaporation is significantly slower than the latter. The unusual behavior could be attributed to the exact match between the limonene molecule and the pore structure of the zeolite framework, which allows it to penetrate deeply into the sodalite cages and thereby retain longer in the matrix.
Overall, this work provides new insights into the host—guest interactions in zeolitic matrices while at the same time introducing a convenient platform for the construction of fragrance-controlled release systems. Experimental Section. Tianjin, China. Deionized DI water was used in all of the experiments. Shanghai, China and used as received. Solid samples were mixed with potassium bromide and compressed into a pellet for the measurements, while the neat fragrances were measured by the liquid film method.
Samples were sputtered with platinum and imaged at an accelerating voltage of 3 kV. The particle size was analyzed by Nano Measurer software version 1. An energy dispersive spectroscopy EDS accessory was also used for imaging and quantifying the element distribution of the samples. The specific surface area was calculated by the Brunauer—Emmett—Teller BET equation from the adsorption isotherm branch.
The total pore volume was obtained at a relative pressure of 0. The micropore size distribution was determined by the Horvath—Kawazoe equation from adsorption isotherm data, while the mesopore size distribution was obtained according to desorption isotherm data via the Barrett—Joyner—Halenda BJH equation.
After filtration, this procedure was repeated by mixing the isolated solid with a fresh batch of solution. The impregnation of zeolite in the salt solution for 24 h was considered as an ion-exchange cycle.
Finally, the separated powder was dialyzed against DI water and lyophilized to yield the desired product as a white solid. Encapsulation of fragrances in zeolites was carried out on a Schlenk line.
Then, an excess of fragrance was added, and the resulting mixture was stirred at ambient temperature for 24 h and then rinsed with n -hexane several times in a N 2 flow to remove residual fragrance on the solid surface. The as-prepared composites denoted as [email protected] ; Z shows the type of cation in the zeolite were put into a vial and stored in a desiccator.
The loading content of fragrance in the composites was calculated by the following equation based on thermogravimetric analyses. The fragrance release experiments were carried out at room temperature according to the previously reported procedure. Four mathematical models were applied to fit the release profiles of [email protected] composites, including a first-order equation eq 2 , a Higuchi equation eq 3 , a Weibull equation eq 4 , and a zero-order equation eq 5. The lattice constants are optimized from the Birch—Murnaghan fit to the total energies as a function of the unit cell volume.
The planewave cutoff energy was set to eV. The structural relaxations have been performed until all forces were smaller than 0. The van der Waals interactions were considered using dispersion corrections.
The molecular van der Waals surfaces, defined as 0. Supporting Information. Author Information. The authors declare no competing financial interest. Controlled release of volatiles under mild reaction conditions: from nature to everyday products. A review. Volatile org. The quite limited longevity of olfactive perception has led to the development of pro-perfumes or pro-fragrances-ideally nonvolatile and odorless fragrance precursors which release the active volatiles by bond cleavage.
Only a limited amt. This Review describes the controlled chem. As the same systems can be applied in different area of research, the scope of this Review covers fragrance delivery as well as the controlled release of volatiles in general. Sustainable chemistry considerations for the encapsulation of volatile compounds in laundry-type applications. ACS Sustainable Chem.
American Chemical Society. Microencapsulation of volatile compds. Melamine-formaldehyde is the industry std. Harsh storage conditions and demanding release characteristics have limited the no. This renders nano- and microencapsulation of volatile compds. The largest drawback of the current technol. This review summarizes the search toward viable, high-performant and sustainable alternatives for the current technol.
First, various techniques to encapsulate volatile compds. Recent relevant encapsulation reports using natural and synthetic shell walls are discussed, while controlled release data are included where possible. Finally, a perspective contg. Accumulation of microplastic on shorelines woldwide: sources and sinks.
Ingestion of microplastic provides a potential pathway for the transfer of pollutants, monomers, and plastic-additives to organisms with uncertain consequences for their health. We show that microplastic contaminates the shorelines at 18 sites worldwide representing 6 continents from the poles to the equator, with more material in densely populated areas, but no clear relation between the abundance of microplastics and the mean size-distribution of natural particulates.
An important source of microplastic appears to be through sewage contaminated by fibers from washing clothes. Forensic evaluation of microplastic from sediments showed that the proportions of polyester and acrylic fibers used in clothing resembled those found in habitats that receive sewage-discharges and sewage-effluent itself.
This suggests that a large proportion of microplastic fibers found in the marine environment may be derived from sewage as a consequence of washing of clothes. As the human population grows and people use more synthetic textiles, contamination of habitats and animals by microplastic is likely to increase. Sol-gel microencapsulation of odorants and flavors: opening the route to sustainable fragrances and aromas.
Royal Society of Chemistry. The sol-gel approach to encapsulate fragrance and aroma chems. Amorphous sol-gel SiO2 is non-toxic and safe, whereas the sol-gel entrapment of delicate chems. Reviewing progress in the fabrication of diverse odorant and flavored sol-gels, we show how different synthetic strategies afford advanced materials suitable for practical application with important health and environmental benefits. Prolonged-release performance of perfume encapsulated by tailoring mesoporous silica spheres.
Flavour Fragrance J. Mesoporous silica MS spheres with size-controllable pore channels and regular spherical shape were used as supports for the encapsulation of hydrophilic perfume. The MS spheres were tailored by expanding pore size in order to have high loading content.
The perfume-encapsulating MS spheres so obtained were followed by assembling 10 layers of polyelectrolyte shell on the microspheres' surfaces for the purpose of good prolonged-release performance. The morphologies and prolonged-release performance of perfume-encapsulating MS spheres with layer polyelectrolyte shells were characterized by transmission electron microscopy, pore size anal.
The results showed that with MS spheres constructed in this way, effective prolonged-release performance can be achieved. We also demonstrated that these MS spheres can indeed be used for the prolonged release of perfume. Effects of fragrance-loaded mesoporous silica nanocolumns on the central nervous system. American Scientific Publishers. Fragrances have rapid effect on our central nervous system, such as making the spirit of relaxation, relieving tensions and refreshing ourselves.
However, the release of fragrances is not stable. Here, we added photo-driven mesoporous silica nanocolumns loaded with sandela [email protected] into wallpaper to obtain fragrant wallpaper [email protected]. We then analyzed the effects of [email protected] and pure sandela treated wallpaper [email protected] on the CNS of mice and explored the internal mechanism of these effects.
Besides, we evaluated the short-term 7 days and long-term 30 days effects of the fragrance treated wallpaper. In behavioristics level, we detected the anxiolytic effects via elevated plus maze and open field test. In tissue level, we analyzed the neural activity in hippocampus, hypothalamus and olfactory bulb regions via measuring the electrophysiol. In cell level, we tested the nerve regeneration in hippocampus, substantia nigra and corpus striatum via immunofluorescence staining with the anti-BrdU antibody.
In mol. Finally, we find that [email protected] had anxiolytic effects on the CNS of mice, and the effects were more significant as time progresses. A novel photothermo-responsive nanocarrier for the controlled release of low-volatile fragrances. RSC Adv. We herein present a facile approach to create polydopamine PDA modified silica-based nanocarriers for use in the encapsulation and photothermally responsive release of the synthetic sandalwood odorant Sandalore SA as a low-volatile model fragrance.
The method involves impregnating mesoporous silica nanoparticles with an ethanol soln. The aroma release was significantly accelerated upon illumination due to the photothermal heating effect of the PDA shell, which is proportional to the coating content and the irradn. Encapsulated recyclable porous materials: an effective moisture-triggered fragrance release system. A moisture-triggered release system was developed using porous metal-org. Release of both hydrophilic Et butyrate and hydrophobic d-limonene fragrance compds.
These materials exhibit exceptional fragrance compatibility and controlled release compared to the current leading encapsulation technol. The moisture-triggered controlled release of a natural food preservative from a microporous metal-organic framework.
In this work we demonstrate that allyl isothiocyanate AITC , a common food flavoring agent and food preservative, can be effectively captured by and released in a controlled manner from a microporous metal-org. Controlled release expts. Further anal. This study represents the first example of making use of MOF porosity in food preservation. Encapsulation and controlled release of fragrances from functionalized porous Metal—Organic Frameworks. AIChE J. In the fragrance and perfume industry, the encapsulation and controlled release of fragrance is important to appeal to consumers and promote the quality of products.
Here, we demonstrate that porous metal-org. The incorporation of functional groups into MOFs can improve the adsorption and release behavior of fragrant mols. The release profiles show that UiO OH 2 can prolong the release of polar fragrances compared with nonpolar fragrances. Both the exptl. The releasing kinetics indicates that pore diffusion is the rate-limiting step of fragrance release from MOFs.
Biocompatible cyclodextrin-based metal-organic frameworks for long-term sustained release of fragrances. The encapsulation of volatile fragrances within porous materials is capable of increasing their stability for long-term controlled release; however, the introduction of low biocompatible carrier materials also increases safety concerns, thus limiting their applications. Two ester- and two terpene-type fragrances were used as model fragrances for encapsulation.
The host-guest hydrophobic and hydrogen-bonding interactions between the fragrant mols. We find that the release profiles of the two ester-type fragrances are linear and can be fitted well by the zero order model, whereas those for terpene-type fragrances show an initial burst release with better fitting using the Weibull model.
KGaA : Weinheim, Germany , Small-Pore Zeolites: Synthesis and Catalysis. In the past decade or so, small-pore zeolites have received greater attention than large- and medium-pore mol. This is primarily due to the commercialization of two major catalytic processes, NOx exhaust removal and methanol conversion to light olefins, that take advantage of the properties of these materials with smaller apertures.
These eight-member ring pores 8MR provide small mols. In total, there are forty-four structurally different small-pore zeolites. Forty-one of these zeolites can be synthesized, and the first synthetic zeolite KFI, was in fact a small-pore material. Although the field of 8MR zeolite chem. This review first focuses on the relevant synthesis details of all 8MR zeolites and provides some generalized findings and related insights.
Next, catalytic applications where 8MR zeolites either have been commercialized or have dominated investigations are presented, with the aim of providing structure-activity relationships. The review ends with a summary that discusses i both synthetic and catalytic progress, ii a list of opportunities in the 8MR zeolite field, and iii a brief future outlook. Zeolites in drug delivery: progress, challenges and opportunities.
Elsevier Ltd. A review : There are continuing attempts to achieve appropriate controlled-release therapeutic systems by designing innovative functional drug delivery systems DDS. Although various types of delivery system have been developed, strategies that have successfully made it to the clinic are rare. Given their diverse structures, zeolites have attracted significant research attention for controlled and targeted drug delivery purposes. The structure of zeolites can be microporous, mesoporous or macroporous, which can be exploited to deliver a variety of therapeutic agents to the target site in a controlled manner.
In this review, we introduce the different types of zeolite, and discuss the challenges and opportunities assocd. Faujasites incorporated tissue engineering scaffolds for wound healing: in vitro and in vivo analysis.
ACS Appl. Interfaces , 5 , — , DOI: Exploring the possibility of using inorg. Micro computed tomog. The summative effect was ideal for growth of dermal fibroblasts and cellular attachment. XRD anal. Coupling with effective reinforcement of faujasites, GH 2.
It exhibited controlled swelling and degrdn. The latter is further supported by capability of faujasites to provide efficient oxygen supply to fibroblast cells. This burdens the consumer with a huge responsibility in choosing the best for themselves as well as the environment. Products emitting the least amount of VOCs are a need of the hour. Its effect could be severally reduced by using indoor and outdoor plants. We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless.
You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together. Please use a genuine email ID and provide your name. Environment Smell good, breathe bad: How scented products add to air pollution Use of hair sprays, hand sanitisers etc emit the same amount of chemical vapours as petroleum from vehicles, even though 15 times more petroleum is burned as fuel By Anuj Behal, Dimple Behal Published: Thursday 03 December But where does the perfume go once it is sprayed on the body?
Who is the end consumer of it? A history Early perfume was made using natural materials such as bark, wood, roots, leaves, flowers and seeds. Changing chemistry The use of scented goods including things such as perfumes, hair sprays, air fresheners, and paints emit the same amount of chemical vapours as petroleum from vehicles, even though 15 times more petroleum is burned as fuel, according to a report in the journal Science by the National Oceanic and Atmospheric Administration NOAA.
What are volatile organic compounds? Download options Please wait Supplementary information PDF K. Article type Paper. Submitted 24 Jul Accepted 09 Oct First published 09 Oct Download Citation. Request permissions. Storage and controlled release of fragrances maintaining a constant ratio of volatile compounds Y. To many people, the word "fragrance" means something that smells nice, such as perfume.
We don't often stop to think that scents are chemicals. Fragrance chemicals are organic compounds that volatilize, or vaporize into the air, which is why we can smell them. They are added to products to give them a scent or to mask the odor of other ingredients. The volatile organic chemicals VOCs emitted by fragrance products can contribute to poor indoor air quality IAQ and are associated with a variety of adverse health effects.
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