Morphological Evolution of Self-Assembled Sodium Dodecyl Sulfate/Dodecyltrimethylammonium Bromide@Epoxy-β-Cyclodextrin Supramolecular Aggregates Induced by Temperature

Bio-based cyclodextrins(CDs)are a common research object in supramolecular chemistry.The special cavity structure of CDs can form supramolecular self-assemblies such as vesicles and microcrystals through weak interaction with guest molecules.The different forms of supramolecular self-assemblies can be transformed into each other under certain conditions.The regulation of supramolecular self-assembly is not only helpful to understand the self-assembly principle,but also beneficial to its application.In the present study,the self-assembly behavior of epoxy-β-cyclodextrin(EP-β-CD)and mixed anionic and cationic surfactant system(sodium dodecyl sulfate/dodecyltrimethylammonium bromide,SDS/DTAB)in aqueous solution was studied.Morphological and particle size characterization found that the SDS/DTAB@EP-β-CD complex,as the basic building unit,self-assembled into worm-like micelles at lower temperatures and vesicles at higher temperatures.Nuclear magnetic resonance(NMR)and Fourier transform infrared spectroscopy(FT-IR)analysis revealed that the driving force for the formation of vesicles and worm-like micelles was the hydrogen bonds between EP-β-CD molecules,while water molecules played an important role in promoting vesicle formation between SDS/DTAB@EP-β-CD units.Herein,the mechanism of the morphologic transformation of SDS/DTAB@EP-β-CD supramolecular aggregates induced by temperature was elucidated by exploring the self-assembly process,which may provide an excellent basis for the development of delivery carriers.

Biodegradable Materials as Nanocarriers for Drugs and Nutrients

Several important drugs and nutritional supplements are limited by their lack of bioavailability.Nanomaterials display unique beneficial properties that might help improve the bioavailability of drugs and nutritional supplements.Unfortunately,nanomaterials produced from synthetic polymers and metals may have similar difficulties with bioavailability and toxicity.Naturally occurring biopolymers are biodegradable and non-toxic and are adaptable to the synthesis of nanoparticles.Drugs and other substances can be encapsulated or embedded in such particles with an increase in bioavailability.The search for biodegradable nanomaterials is an active research field.This review summarizes the research on nanocrystalline cellulose,starch,lignin,and other biological and environment-friendly nanocomposites which are commonly used as nanocarriers for drugs and nutrients.Further,prospects for the use of biodegradable nanomaterials in targeted therapy,including environmentally responsive therapy,are discussed.

Research Advances in Photocatalysis of Inorganic Hollow Spheres

Inorganic hollow spheres have shown their superiority in photocatalytic area due to the large specific surface area, controllable structure and their own special optical, electrical, magnetic properties. According to the classification of inorganic hollow spheres as photocatalysts, recent research progress and application status have been summarized in this paper. At last, the future developments of inorganic hollow spheres in photocatalytic field have been discussed.

纳米香料技术的现状与发展

纳米加香技术可以提高香料在基材内的负载并实现可控释放,从而提高芳香产品质量,增加产品对消费者的吸引力.本文对国内外的纳米加香技术的当前状况和研究进展进行了评述,指出了当前香精加香技术存在的问题,提出了基于基材纳米结构的直接纳米加香技术具有的发展潜力和优势,并讨论了实现该技术在芳香高端产品的大规模应用上仍需解决的关键科学问题.

基于纳米尺寸低聚硅倍半氧烷潜香体的合成、表征及其香料醛分子缓释性能研究

在功能性香精与香料的应用中,香气怡人与留香持久是需要长期挑战的目标.为了达到该目标,通过形成可切断的共价键来实现香料的缓释留香是有效的途径之一.基于此,本文合成了一系列基于纳米尺寸的低聚硅倍半氧烷(POSS)基体、缩醛结构作为键链的纳米潜香体.该类潜香体在温和条件下能够缓慢地释放香料醛分子.模拟仿生的酸性环境条件,研究了pH对潜香体释放香料分子的影响,发现酸性强弱对香料分子的释放有着重要的关系, pH值也与缩醛键链接的化学键的断裂成正相关关系.在弱酸环境中,释放相对较慢,达到释放平衡的时间相对较长,具有优异缓释的效果.此外,利用该类新颖的潜香体对丝绸、纸张进行负载,并研究了仿生环境下的香料醛分子的释放,与单纯香料醛分子对照样进行了对比和讨论.

高分子纳米香精制备的研究进展

香精是种类和功能多样的精细化学品,已经广泛应用于人们生活中.但因香精的主要成分为沸点低、易挥发的物质,所以存在留香时间短、对环境敏感的缺点,限制了其被广泛的应用.如何控制和减缓香料的挥发,稳定香精的性质是提高香精应用效率的难点和重点.目前,利用高分子材料将易挥发的香精纳米化,构建缓控释体系,可以有效解决上述问题.本文对高分子纳米香精的制备方法及其研究进展进行了综述.

蚕丝织品、牛皮革和壁纸原纸的纤维孔隙结构及吸附性能

香料的纳米化封装及相关的芳香整理技术已经成为有效实现香气物质缓慢释放的重要手段.因此,了解纳米载体与基材之间的相互作用机制对于香料纳米技术的应用和改进至关重要.本文以蚕丝织品、牛皮革和壁纸原纸为对象,综合运用多种表征技术分析,研究了3种基材的纤维形貌、孔隙结构及孔径分布的基本特征,并以4种不同直径的纳米二氧化硅(SiO2)作为模型载体考察其在上述基材上的吸附行为.结果表明, 3种基材缝隙宽度小于1μm的孔隙百分比有显著差异,丝巾、皮革、原纸分别为0.3%、23.8%和4%,与其比表面积呈正相关的关系.纳米载体在基材上的附着强度及其分布状态不仅依赖于载体自身的尺寸,而且与纤维的物质属性及孔隙结构密切相关.小粒径SiO_2粒子(20 nm)可牢固附着于单根纤维表面,随粒径增大则倾向于嵌入到纤维缝隙或黏附在缝隙边缘.本研究对于纳米香料递送体系的设计具有一定的理论指导意义.

环境响应控制潜香分子制备及其释放研究进展

潜香体是通过化学键合手段,将香料分子与特定基团链接而形成的香料控释体系,在特定条件下控制化学键断裂而释放香料.潜香体能避免因香料本身的高挥发性而引起的留香时间短等问题,从而满足众多加香产品持久留香的要求;该需求反过来又极大促进了潜香体的研究.大多数加香产品是日常生活中的必需品,故基于环境控制潜香体的香料释放备受关注.本文着重介绍了在温和环境条件下潜香分子制备与释放性能的研究进展,特别是对不同pH响应及光响应的潜香体进行了详细的综述.另外也简单介绍了不常见的氧气响应型潜香体,并对潜香体进一步的设计与研究进行了展望.

光敏纳米香料应用于壁纸及香气缓控释的研究

利用简单的溶胶-凝胶法制备了介孔二氧化硅纳米棒,并偶联小分子光敏剂ICPES-AZO.通过介孔二氧化硅吸附能力,对檀香803进行载香,制备出光敏性纳米香料.随后,将纳米香料附着在壁纸上,形成芳香壁纸.最后,对芳香壁纸上檀香803的释放进行了检测.研究表明,光照条件下香料可以持续释放,黑暗条件下缓慢释放,具有显著的缓控释效果.

Reactive mesoporous silica nanoparticles loaded with limonene for improving physical and mental health of mice at simulated microgravity condition

Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can improve the physical and mental health of astronauts in a way that moisturizes them softly and silently.However,the strong volatility of fragrances and inconvenience of aroma treatment greatly limit their application in the field of spaceflight.In this study,reactive mesoporous silica nanoparticles were prepared to encapsulate and slowly release limonene.The limonene loaded nanoparticles were named limonene@mesoporous silica nanoparticles-cyanuric chloride(LE@MSNs-CYC).LE@MSNs-CYC were then applied to wallpaper to improve the convenience of aromatherapy.LE@MSNs-CYC could chemically react with the wallpaper,thus firmly adsorbed on the wallpaper.In the following,the mice were treated with hindlimb unloading(HU)to simulate a microgravity environment.The results showed that 28-day HU led to an increase in the level of anxiety and declines in learning,memory,and physical health in mice.LE@MSNs-CYC showed significant relief effects on anxiety,learning,memory,and physical health of HU treated mice.Subsequently,the molecular mechanisms were explored by hypothalamic-pituitary-adrenal axis related hormones,immune-related cytokines,learning,and memory-related neurotransmitters and proteins.

Synthesis and characterization of novel biocompatible nanocapsules encapsulated lily fragrance

Fragranced products are wildly used in our daily life. However, their storage, application and quality are severely influenced by their strong volatility. In order to overcome these natural defects of fragrances,fragrance encapsulation approaches have been developed recently. In this study, a mild, simple and lowcost method of fragrance encapsulation was invented. Liposomes composed of soya lecithin/DSPEPEG2000/PLGA were prepared to encapsulate lily fragrance(LF). And these nanosized fragrance products was named LF-NPs. The hydrodynamic diameters of LF-NPs were approximately 100 nm and their encapsulation efficiency was up to 21.9%. Besides, LF-NPs could also prolong the release time of lily fragrance. Finally, the cytotoxicity tests indicated that LF-NPs offered biocompatibility. Therefore, LF-NPs were expected to have application prospects.

Mesoporous silica nanospheres with the ability of photo-driven releasing sandela 803 for the application to wallpaper

Fragrances are widely used in our daily life and have made great contributions to creating a clean and fresh healthy air environment. However, the rapid volatilization severely influences their storage,application and quality. Therefore, it is necessary and urgent to develop approaches to controllably release the odorants as demanded. In this study, photo-driven mesoporous silica nanospheres loaded with sandela 803 was designed, prepared and named as S803@MS-S. S803@MS-S possessed ordered mesoporous, large specific surface area and pore volume. After adsorption of sandela 803, the S803@MSS was added into wallpaper to prepare fragrant wallpaper S803@MS-S-W. And this wallpaper exhibited excellent sustained and controlled release performances stimulated by light.

Controllable Fragrance Release Mediated by Spontaneous Hydrogen Bonding with POSS–Thiourea Derivatives

The purpose of achieving the long-lasting fragrance perception leads to nanocarrier-based profragrances in perfume applications.Herein,we report a family of novel profragrance systems based on polyhedral oligomeric silsesquioxane(POSS)derivatized thioureas(POSS thioureas)that enable linkage of volatile carbonyl fragrances with the spontaneous formation of fragile hydrogen bonds.This profragrance platform addresses the dilemma of the volatile nature of aroma-materials on the one hand,and the desired long-lasting effects on the other.Their releasing performance as profragrances is investigated by headspace solid-phase microextraction(SPME)in combination with gas chromatography(GC)analysis under water as the external humidity stimulus,indicating that the fragrance concentration released from the POSS–thiourea-based profragrance is up to four times higher than the neat reference of the corresponding perfume aldehydes.Furthermore,deposition of the novel profragrance system onto wallpaper results in excellent retentive capacity for volatile aldehydes.Given the low essential toxicity,the POSS–thiourea system has been demonstrated as a suitable profragrance for practical application to perfume delivery.

Engineering photo-controllable fragrance release with flash nanoprecipitation

Controllable profragrance nanoparticles are in great demand for long-lasting scent in flavor and fragrance industries.However,the practical applications of controllable fragrance release are limited by the non-tunable size,structural heterogeneity and poor reproducibility.Herein,a coumarin-derived phototrigger(CM-OH)is covalently conjugated with alcohol fragrances to obtain the corresponding profragrances(CM-R)which enable to release fragrances under the light controlling conditions.Furthermore,we introduce a new engineering strategy to construct fine tunable and highly uniform profragrance nanoparticles with flash nanoprecipitation(FNP)technology,which features commercial available amphiphilic pluronic F127 polymers by encapsulation of photoactivatable profragrances CM-R in hydrophobic cores to enhance the long-lasting photo-controllable fragrance release.With the assistance of FNP technology,amphiphilic pluronic polymer and profragrances CM-R in organic solution are instantaneously mixed and subsequently precipitated in the multi-inlet vortex mixer(MIVM),thus obtaining the pluronic F127-encapsulated profragrance nanoparticles with good homogeneity.Compared to the traditional thermodynamic encapsulation method,the novel kinetic FNP technology can not only tune the size of profragrance nanoparticles with narrow distribution,but also distinctly improve the batch-to-batch reproducibility,which affords an alternative method for scale-up preparation of amphiphilic profragrance nanoparticles in precisely controllable fragrance delivery system.

Cationic and temperature-sensitive liposomes loaded with eugenol for the application to silk

Silk has been widely used in the clothing industry due to their soft and smooth features,good biocompatibility,good heat dissipation,warmth and ultraviolet resistance.The application of fragrance to silk can significantly improve the performance of silk.However,there are two key scientific problems that need to be solved:slowing down the release rate of fragrances and increasing the scent lasting time of silk.In this study,cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol.These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner.The liposomes adhered to the silk through electrostatic adsorption interaction.The positive charge on the fragranceloaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.

Reactive nano-essential oils for sustained release of essential oils and application to wallpaper

Essential oils are a volatile and aromatic substance with a variety of active biological activities.However,the excessive volatility and inconvenience of the use of essential oils limit their applications.In this study,we developed a reactive mesoporous silica nanoparticle(rMSNs)based on cyanuric chloride modification for essential oil encapsulation and commodity adhesion.The large pore volume and specific surface area of rMSNs facilitate the nanoparticles adhering to a large amount of essential oil and achieve the sustained release of essential oil,thus prolonging the fragrance retention time of essential oils.The reactive nanoessential oils can form covalent bonds with the wallpaper,thereby remarkably improving the adhesion of the reactive nano-essential oils on the wallpaper and preventing the reactive nano-essential oil from deadhering from the wallpaper.The active nano essential oil simultaneously overcomes the intense volatility of the essential oil and inconvenience in use,has a simple preparation process and low cost,and has great application potential.

Zwitterionic comb-like lipid polymers encapsulating linalool for increasing the fragrance retention time

Fragrances are widely used in cosmetics,apparel and detergents.However,the rapid evaporation of the aro ma shortens the useful life of the aromatic product.Therefore,improving the fragrance retention time of aromatic products and prolonging the service life of aromatic products are the key scientific problems that need to be solved in current aromatic products.In this study,zwitterionic comb-like lipid polymers were synthesized to encapsulate the fragrance molecule linalool.The results showed that the zwitterionic comb lipid molecules were capable of encapsulating more linalool than linear lipid molecules.At the same time,the zwitterionic comb-like lipid molecules also limited the slow release rate of the aroma,thereby increasing the fragrance retention time of the nano-fragrance.

Preparation of hollow mesoporous silica nanorods for encapsulating and slowly releasing eugenol

Fragrances are widely used in many aspects of our lives.They cannot only make people happy,but also treat many diseases.However,excessively fast evaporation rate is one of the main obstacles to the use of spices.In this study,mesoporous silica nanorods(MSNRs)and hollow mesoporous silica nanorods(HMSNRs)were prepared to encapsulate eugenol.These two nano-fragrances were named eugenol@MSNRs and eugenol@HMSNRs,respectively.The morphologies,size,interior structures and pore performances of MSNRs and HMSNRs.Besides,the performances of encapsulation and fragrance release of eugenol@MSNRs and eugenol@HMSNRs were compared and analyzed.The results showed that eugenol@HMSNRs encapsulated more fragrance and were faster to encapsulate compared with eugenol@MSNRs.Both the release rates of eugenol from eugenol@MSNRs and eugenol@HMSNRs were slow.But the eugenol was released from eugenol@MSNRs more slowly.

Preparation of mesoporous silica nanoparticle with tunable pore diameters for encapsulating and slowly releasing eugenol

Fragrances are frequently added to a variety of products,including food,cosmetics and health products.However,the high volatility and instability of essence limit its application in some fields.In this study,mesoporous silica nanoparticles(MSNs) were prepared to encapsulate eugenol,which could reduce the volatilization of the fragrance molecules.A facile approach was presented to synthesize MSNs with three different pore diameters for encapsulating eugenol.In addition,the properties of MSNs including mean particle size,morphology,encapsulating efficiency and release tendency were charac terized.Results showed that the larger the pore diameters of MSNs,the more aromatic molecules were adsorbed.Furthermore,the release mechanism was described as the smaller the pore diameters of MSNs,the slower the release of eugenol.