We have developed new inorganic-based drug delivery systems through the hybridization of indole-3-acetic acid (IAA) and layered metal hydroxide such as zinc basic hydroxide salt (ZBS) and zinc aluminum layered double hydroxide (ZALDH). A coprecipitation method as well as an ion-exchange route is found to be commonly effective in synthesizing both IAA-ZBS and IAA-ZALDH nanohybrids, in which the tilted bilayers of IAA are stabilized in the interlayer space of layered metal hydroxide lattice. According to the FT-IR spectroscopic analyses, IAA molecules interact more strongly with the ZBS lattice than the ZALDH one, which is due to the formation of coordination bonds between carboxyl groups of the guest species and coordinatively unsaturated Zn(OH) 3 units of the host ZBS lattice. Such an interaction gives rise to a slower release of the IAA molecules from the ZBS-based nanohybrid than from the ZALDHbased one. The present results underscore that the layered hydroxydouble salt like ZBS makes it possible to design and develop new efficient drug-delivery systems with the suspended release of guest molecules. IntroductionRecently, intense research interests have paid on layered inorganic solids because of their ability to encapsulate and immobilize various bio-and organic molecules in the interlayer space. 1-5 In particular, layered double hydroxide (LDH) with brucite-type lattice can act as a gene reservoir and/or a drug-delivery system (DDS). 3,4,6-11 The positive surface charge of LDH layer caused by the partial substitution of divalent cations with trivalent ones makes it possible to intercalate negatively charged drug-or biomolecules like DNA. For the practical use of LDH as a drug delivery vector, it is very important to control the release rate of drug molecules, 11 because it determines the retention time of drug molecules in vivo. Such a regulation of the disintercalation kinetics of intercalated organic molecules can be achieved by tuning the chemical interaction between host and guest. It has been well-known that metal vacancy in the brucitelike layer leads to the phase transformation into hydroxydouble salt (HDS) such as Zn 5 OH 8 (NO 3 ) 2 ‚2H 2 O, in which coordinatively unsaturated Zn(OH) 3 units are formed up and down side of vacant octahedral sites of brucite-like layers, and exposed to the interlayer space of the HDS lattice. Like the LDH phase, there are exchangeable interlayer anionic species in the HDS lattice to neutralize the positive charge of host layer and hence this material has an ability to form the intercalation complexes with negatively charged organic molecules. [12][13][14][15] The presence of the coordinatively unsaturated Zn(OH) 3 units directed to interlayer space allows the HDS phase to strongly interact with guest molecules. In this regard, it is highly feasible that the intercalation of drug molecules into the HDS phase would produce new inorganicbased DDS with slow release kinetics of guest drug molecules. Moreover, the HDS phase has an additional advantage over the LDH phase such ...

Nanoporous carbon materials have been widely utilized for myriad applications owing to their intriguing physicochemical properties. Development of green and clean synthetic techniques/procedures to generate nanoporous carbon materials especially derived from inexpensive waste precursors/resources has rejuvenated the chemistry of carbon materials owing to the abundant nature and low cost of these sources and their ability to generate unique surface/porous structures. These nanoporous carbon materials have been heavily explored in multiple sectors such as soil/water remediation, adsorption and separation, catalysis, energy storage/conversion, capture and conversion of carbon dioxide. In this topical review, the recent state‐of‐the‐art research progress achieved in the design and development of waste‐derived advanced functionalized porous carbon materials are summarized. The various lab‐specific approaches and methodologies involved in synthesizing these materials are discussed in detail. In addition, the potential applications of waste‐derived functionalized porous carbons in the fields of environment, energy storage, and conversion applications are highlighted. Finally, a discussion on a few suggestions for future research is concluded. It is believed that this review provide inspiration for many new research activities over a wide range of disciplines.

Encapsulation of L-ascorbic acid (vitamin C) within a bio-compatible layered inorganic material was achieved by coprecipitation reaction, in which the layered inorganic lattice and its intercalate of vitamin C are simultaneously formed. The nano-meter sized powders of vitamin C intercalate thus prepared was again encapsulated with silica nano-sol to form a nanoporous shell structure. This ternary nanohybrid of vitamin Clayered inorganic core-SiO2 shell exhibited an enhanced storage stability and a sustained releasing of vitamin C. Furthermore, the nano-encapsulation of vitamin C with inorganic mineral was very helpful in delivering vitamin C molecules into skin through stratum corneum, facilitating transdermal penetration of vitamin C in topical application.