U. Chinna Rajesh

Novel 4-aminoquinoline-pyrimidine based hybrids with improved in vitro and in vivo antimalarial activity.

A class of hybrid molecules consisting of 4-aminoquinoline and pyrimidine were synthesized and tested for antimalarial activity against both chloroquine (CQ)-sensitive (D6) and chloroquine (CQ)-resistant (W2) strains of Plasmodium falciparum through an in vitro assay. Eleven hybrids showed better antimalarial activity against both CQ-sensitive and CQ-resistant strains of P. falciparum in comparison to standard drug CQ. Four molecules were more potent (7-8-fold) than CQ in D6 strain, and eight molecules were found to be 5-25-fold more active against resistant strain (W2). Several compounds did not show any cytotoxicity up to a high concentration (60 μM), others exhibited mild toxicities, but the selective index for the antimalarial activity was very high for most of these hybrids. Two compounds selected for in vivo evaluation have shown excellent activity (po) in a mouse model of Plasmodium berghei without any apparent toxicity. The X-ray crystal structure of one of the compounds was also determined.

Ethylenediammonium diformate (EDDF) in PEG600: an efficient ambiphilic novel catalytic system for the one-pot synthesis of 4H-pyrans via Knoevenagel condensation

A novel ethylenediammonium diformate–polyethylene glycol (EDDF-PEG600) system was developed as a catalyst for the Knoevenagel condensation and Knoevenagel initiated three-component one-pot synthesis of 4H-pyrans at room temperature with high yields and in short reaction times. Further, the EDDF-PEG600 catalytic system was recycled six times without any appreciable loss in its activity and hence can be termed as a green, environmentally benign catalytic system. A plausible mechanism depicting the ambiphilic nature of EDDF (catalyst) and PEG (promoting medium) acting in synergy has been proposed.

Proline confined FAU zeolite: heterogeneous hybrid catalyst for the synthesis of spiroheterocycles via a Mannich type reaction

A novel L-proline confined FAU zeolite catalyst system has been developed by confinement of L-proline in faujasite zeolite and its catalytic activity has been tested in the aqueous mediated synthesis of novel 1′,3′-di-(4-methylphenyl)-2′,3′,4′,6′-tetrahydro-1′H-spiro[indoline-3,5′-pyrimidin]-2-one (4a) and 1′,3′-di-(4-methylphenyl)-2′,3′,4′,6′-tetrahydro-1′H-spiro[indene-2,5′-pyrimidin]-1(3H)-one (4d) for the first time via the one-pot three-component condensation of lactams/cyclic ketones, amines and aqueous formaldehyde. The recyclability of the novel catalyst system was studied, which resulted in no loss of catalytic activity up to five cycles.

Functionalized superparamagnetic Fe3O4 as an efficient quasi-homogeneous catalyst for multi-component reactions

Tetrabutylammonium valinate ionic liquid [NBu4][Val] supported on 3-chloropropyltriethoxysilane grafted superparamagnetic Fe3O4 NPs (VSF) was synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The VSF catalyst was used as an efficient “quasi-homogeneous” catalyst for the multi-component synthesis of 1,4-dihydropyridines and 2-amino-4-(indol-3-yl)-4H-chromenes at room temperature. The VSF catalyst was recovered using an external magnet and recycled six times without a significant loss in the catalytic activity. Moreover, VSF as a “quasi-homogeneous” catalyst can bridge the gap between homogeneous and heterogeneous catalyses.

Copper NPs supported on hematite as magnetically recoverable nanocatalysts for a one-pot synthesis of aminoindolizines and pyrrolo[1,2-a]quinolines

Cu NPs such as CuO and Cu2O mixed oxides supported on a hematite surface (Cu@Fe2O3) were achieved using a facile hydrothermal method in a single step. Various techniques such as X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDAX elemental analysis, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS) were used for the characterization of the synthesized Cu@Fe2O3 magnetically recoverable nanoparticles (MNPs). The catalytic potential of the Cu@Fe2O3 NPs was explored for the synthesis of aminoindolizines and pyrrolo[1,2-a]quinolines via an A3 coupling reaction. The present catalytic system offers advantages such as high catalytic activity in a short reaction time, recovery of the catalyst by an external magnetic field and the catalyst being recycled six times without significant loss of its activity.

CuO@Fe2O3 catalyzed C1-alkynylation of tetrahydroisoquinolines (THIQs) via A3 coupling and its decarboxylative strategies

C1-Alkynylation of tetrahydroisoquinoline (THIQ) was achieved via the A3 coupling strategy from the reaction of THIQ as a secondary amine, aldehydes and alkynes using the CuO@Fe2O3 nanocatalyst under green reaction conditions. The wide scope of the present method was studied using various aliphatic/aromatic aldehydes and alkynes to afford the corresponding C1-alkynylated products in quantitative yields. Moreover, the present catalytic system was found to be versatile for the decarboxylative A3 coupling strategy with improved progress of reactions by replacing the alkynes with phenylpropiolic acid under optimized conditions. The present catalytic system was found to be robust, magnetically recoverable and recyclable 5 times without significant loss in its activity, offering a low E-factor and high atom economy (AE).

CCDC 1421517: Experimental Crystal Structure Determination

Related Article: U. Chinna Rajesh, Upasana Gulati, Diwan S. Rawat|2016|ACS Sustain.Chem.Eng.|4|3409|doi:10.1021/acssuschemeng.6b00470

Designing of nano catalysts for sustainable multi-component synthesis of 3-substituted indoles

Most people have experienced to see yellowish orange precipitation or float in springs, ditches, or streams where groundwater outwells (Fig. 1). We discovered that this unlovely precipitation was a mass of very complicated unique structure produced by Fe/Mn-oxidizing bacteria. A type of aquatic Fe/Mn-oxidizing bacteria, the genus Leptothrix, produces uniquely-shaped microsheaths (ca. 1 m in diameter) ubiquitously in natural hydrosphere at ambient temperature (Figs. 2, 3). The sheath is characterized by an extracellular, microtubular, Feor Mnencrusted structure. Basic sheathconstruction proceeds in two steps under culture conditions: i) release of saccharic and proteinous fibrillar exopolymers from bacterial cells and their initial assemblage and ii ) the chemical interactions between the organic exopolymer fibrils and aqueous-phase inorganic ions (Fig. 4).D the last twenty years, nanofluids have shown desirable thermal properties and negligible increase in viscosity when compared to their base liquids without dispersed nanoparticles. These features have opened the door to a wide range of engineering applications, such as microelectronics cooling and biomedical applications, such as nanodrug delivery for cancer therapy. According to the literature, two approaches are commonly used to study the nanofluid heat and fluid flow; namely, the homogenous (single-phase) approach and the two-phase approach. In most of the two-phase studies, thermal equilibrium conditions (the same temperature) are considered for the phases which is not usually the case.Polymer or copolymer based expanded graphite (EG) reinforced nanocomposites were prepared by in situ polymerization technique without using any emulsifier. Graphite shows excellent electrical, mechanical and thermal properties and possesses high aspect ratio and low density, for which graphite taken as filler for preparation of nanocomposites. EG was prepared by treatment of raw graphite with a mixture of concentrated H 2 SO 4 and HNO 3 (ratio 4:1, v/v) followed by heating at 900°C for one minute in a muffle furnace. The synthesized nanocomposites were characterized by Fourier Transform Infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The morphology of nanocomposites was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrical, mechanical, thermal and gas barrier properties of synthesized nanocomposites were measured and it was found that these properties were enhanced with increasing proportion of EG. Polyacrylonitrile (PAN)/EG nanocomposites were prepared with different proportions of EG. The tensile strength and electrical conductivity of PAN/EG nanocomposites were measured and it was found that both properties found to be increased with increase in EG concentrations. The oxygen permeability of virgin PAN and PAN/EG nanocomposites was measured and it was found that oxygen permeability of PAN/EG was reduced substantially approximately 13 times with increase in EG content. Poly (methyl methacrylate)/Expanded graphite (PMMA/EG) nanocomposites were prepared by the incorporation of EG in various proportions (1, 2, 3, 4 and 5%) with PMMA The thermal stability and electrical conductivity of PMMA/EG nanocomposites were improved by dispersion of EG with PMMA matrix. Oxygen permeability of PMMA/EG nanocomposites was calculated and it was found that, permeability was reduced by approximately 10 times with rise of EG proportion. Polymethylmethacrylate-co-polyacrylonitrile/Expanded graphite (PMMA-co-PAN/EG) nanocomposites were prepared by the incorporation of EG in various proportions (1, 2, 3 and 4%) into PMMA-co-PAN through in situ emulsifierfree emulsion polymerization method. The conductivity and thermal stability of nanocomposites were measured as function of EG concentration. Oxygen permeability of PMMA-co-PAN/EG was approximately reduced by 8 times with increase of graphite proportion. This is because of the fact that the graphite nanoplatelets act as a physical obstacle regarding the movement of the gas.R redox flow battery has attracted considerable attention as a promising stationary energy storage technology to stabilize the power grid and tackle the intermittency of the renewable energies. The cell architecture of flow battery allows the energy capacity to be determined by the electrolyte volume while the power rating by the stack size, thus separating the power and the energy. This feature gives flow battery excellent scalability and modularity for scale-up, and exceptional design flexibility to meet the power-to-energy ratio requirement in different applications.L temperature hydrothermal synthesis of different ZnO nanostructures with rational control over their morphology and size is important for a wide range of sensing applications. ZnO nanostructures with different dimensionalities have been synthesized through low temperature hydrothermal techniques. One dimensional ZnO NWs have been synthesized with and without the assistance of a seed layer, with a higher degree of control over their structure, morphology, density and dimensions. The large scale production of two dimensional ZnO nanodisks with a high fraction of exposed polar facets have also been produced through using zinc counter ions with preferential capping capabilities on defined facets. Furthermore, using a multistage hydrothermal synthesis, a range of three dimensional hierarchical ZnO nanostructures grown from initial monomorphological ZnO nanostructures/seeds has been reported. The growth parameters, such as the nutrient concentration, quantity of polyethylenimine, growth time, and zinc counter ions have had a substantial impact on the morphological properties of the grown structures. Gas sensors based on ZnO nanostructures with different dimensionalities have been fabricated and analyzed. The effect of the exposed polar facets on sensing properties of ZnO nanostructures has been investigated and found to play a crucial role in the overall performance of the gas sensors. Ultraviolet activation mechanisms for ZnO gas sensors has been presented and discussed as a substitute to conventional thermal activation. Finally, an effective approach to enhance the performance of ZnO nanostructured gas sensors by using hierarchical structures instead of their mono-morphological counterparts has been demonstrated. Hierarchically ZnO structures display an enhancement of gas sensing performance and exhibit significantly improved sensitivity and fast response to gases in comparison to other mono-morphological ZnO, such as nanoparticles, nanowires, or nanodisks. In addition to the high surface-to-volume ratio due to its small size, the nanowire building blocks show the enhanced gas sensing properties mainly ascribed to the increased proportion of exposed active (0001) planes, and the formation of many nanojunctions at the interface between initial ZnO nanostructure and secondary nanowires.M devices employing magnetic nanoparticles can serve as a useful platform for understanding and developing diagnostic and therapeutic instruments and techniques for medical applications. Magnetic particles based sensors have many advantages over the standard laboratory based diagnostic protocols. The focus of this paper is to study the transport of magnetic particles in microfluidic devices by numerical simulations. Numerical simulations of transport of magnetic particles and their interaction with the fluid in the presence of a magnetic field are conducted in microfluidic devices by solving the governing equations of fluid dynamics and electrodynamics. These studies are of relevance in development of bioMEMS for Magnetic Drug Targeting (MDT) applications.I our group the molecular charge transfer (CT) complexes including photoreactive species such as Ag+, [Ru(bpy)3], and methyl viologen have been widely examined to elucidate their possibility as new types of photoconductors. It is anticipated that utilizing the photoreactive species as a trigger of CT, the counter species are doped with carriers under irradiation to exhibit unusually large photoconductivity. The π-electron-donor molecules with extended molecular orbitals are suitable for such counter species, because they are redox-active and aggregate in the solid state to form conduction pathways. NMQ[Ni(dmit)2] (NMQ=N-methyl quinolinium, dmit=1, 3-dithiol-4, 5-dithiolate anion) functions as a diamagnetic insulator with an activation energy, Ea(dark), of 0.20 eV. However, at 300 K it exhibits ~40 times higher conductivity under UV irradiation (375+5 nm, 15.7 mWcm-2) (σUV) than it does under dark conditions (σdark). The ratio σUV/σdark rapidly increases with decreasing temperature and reaches ~880 at 200 K. From the temperature dependence of σUV the activation energy under irradiation, Ea (UV), is 0.12 eV. These observations cannot be explained as the result of sample heating during UV irradiation. Rather, X-ray photoelectron spectra of sulfur and nitrogen atoms, the calculated band structure and UV-Vis spectra of the salt all indicate that CT takes place from Ni(dmit)2 to NMQ upon exposure to UV light. Owing to the redox activity of both molecular species, the CT transition is expected to provide a larger number of carriers than are usually associated with HOMO-LUMO interband transitions, thus accounting for the unusually large photoconductivity of NMQ[Ni(dmit)2].P cellulose nitrate (CN) and blends of cellulose nitrate and poly (caprolactone) (PCL) were electrospun to form nonwoven mats. Mixed solvent systems of tetrahydrofuran (THF) and N, N-dimethylformamide were employed. The concentrations were varied to obtain sub-micron and nanoscale fiber mats. These fiber mats were analyzed using scanning electron microscopy (SEM), contact angle analysis, X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA). The fiber morphology, surface chemistry and contact angle data show that these electrospun materials exhibit promising applications in the biomedical field.O of the most fundamental laws of nature is the alternate arrangement of cationic and anionic species in an ionic solid. Thus, it is very hard to imagine that a number of inorganic anions come close to each other unless Coulombic repulsion is eased by the presence of polar molecules. As part of our continuing research on the development of chiral multinuclear and supramolecular coordination systems with thiol-containing amino acids, we designed and synthesized a cationic AuI4CoIII2 hexanuclear complex having both D-penicillamine and 1, 2-bis(diphenylphosphino)ethane. Remarkably, this complex was found to crystallize with appropriate inorganic anions to form ionic crystals, in which sixchiral AuI4CoIII2 complex-cations are aggregated into anoctahedron-shaped supramolecular structure, with the concomitant aggregation of inorganic counteranions into an unprecedented cluster structure. Herein, a series of ionic crystals of this compound, which show the unusual aggregation of inorganic anions, will be presented.P of materials are fundamentally dependent on their electron state, which is largely reflected by the electron work function (EWF). A higher work function corresponds to a more stable electronic state with a higher resistance to any attempt of changing the state or related states of a material, such as crystal structure or microstructure caused by mechanical and electrochemical processes. In this talk, close correlation between EWF and material properties will be demonstrated. With this simple characteristic parameter, many material intrinsic properties and processes could be analyzed without involving complex theoretical treatments. Particular attention will be put on the possibility of using EWF as a fundamental parameter for material design, which provides information or clues in a simple or straightforward way for material modification and development. Using Cu-Ni alloy as an example, the correlation between the electron work function (EWF) and mechanical and tribological properties will be demonstrated. One may see that properties of the alloy vary with the electron work function when composition changes, implying that properties of a material can be modified using elements with appropriate work functions. This should also be applicable for tailoring inter-phase boundaries or interfaces.B is a typical nanocomposite mainly composed of carbonate containing non-stoichiometric hydroxyapatite nanocrystals and type-I collagen molecules. They aligned along each other in the primary structure of bone and realize strong but biologically resorbable nature. Our group hypothesized that artificial bone with similar chemical composition and nanostructure would be excellent materials for bone regeneration as the same as natural bone. Simultaneous titration of Ca(OH)2 and collagenH3PO4 solutions under controlled reaction pH and temperature allows to synthesize bone-like nanostructured hydroxyapatite/ collagen nanocomposite (HAp/Col) very easily. The HAp/Col can be formed into dense and porous bodies, membrane and self-setting paste. The HAp/Col is incorporated into bone remodeling paste when it is implanted into bone defect. The porous body of the HAp/Col (HAp/Col sponge) showed sponge-like viscoelasticity in wet condition and fit to any shape of bone defect very easily. The HAp/Col sponge showed higher efficacy for regenerating small to large bone defect in comparison to bioderadable β-tricalcium phosphate porous body in human clinical trial, by its excellent bioactivity and fitting ability to bone defects. The HAp/Col sponge is already sold in Japan as Refit®. Recently, we found that the HAp/Col coating on Ti metal accelerate by 3 times to form direct bonding between host bone and Ti implant. In addition, paste for minimum invasive surgery as well as 3D printing and gene transfer substrate using the HAp/Col were investigated. Including these, possibility of the HAp/Col nanocomposite will be presented in the symposium.T novel poly(e-caprolactone)/poly(lactic acid), (PCL/PLA) composites were prepared with palm press fibers by melt extrusion. The test specimens were fabricated by injection molding. The rate of biodegradation of the composites was studied using normal soil burial method. Field emission scanning electron microscopy (FESEM) was employed to study the surface morphology of the biodegraded composites. Compatibilization and fiber reinforcement accelerated the rate of biodegradation of the composites. This was confirmed by the surface morphology and residual weights of the biodegraded composites. The rate of biodegradation increased as fiber load increased from 10 wt. % to 25 wt. % in the composites.A crystal of dithiolene complex with supramoelcular cation, (m-fluoroanilinium+) (dibenzo[18]crown-6)[Ni(dmit)2] exhibiting ferroelectric transition at 346 K originating from dipole inversion due to flip-flop motion of the aryl moiety in the supramolecular cation have been reported. The supramolecular cations are advantageous for the development of the multifunctional materials based on ferroelectrics by combining with various functional anions. In this study, (3-fluoro-4-methoxyanilinium+)([18]crown-6) [MnCr(oxalate)3] -, (anilinium)(benzo[18]crown)[MnCr(oxalate)3] -, and (m-fluoroanilinium+)(dicyclohexano[18]crown-6) [MnIICrIII(oxalate)3]were synthesized in order to develop multiferroic materials coexisting a ferromagnetism and a ferroelectricity. The crystal 1 had a structure (monoclinic, Cc) with the two-dimensional honeycomb structure of [MnCr(oxalate)3] -. Supramolecular cation was formed between 3-fluoro-4-methoxyanilinium+ and [18] crown-6 through hydrogen bonds. Alternate stackings of the cationic and anionic layers were found along the c axis. Similar packing motives were observed in the crystals 2 and 3 with the space groups of monoclinic, P21 and orthorhombic P212121, respectively. The [Mn Cr(oxalate)3] had the two-dimensional honeycomb structures and the supramolecular cations, (anilinium+)(B[18]crown) and (m-fluoroanilinium+)(DCH[18]crown-6) were also formed in the chiral structures. All crystals exhibited ferromagnetic orders between S=5/2 on MnII and S=3/2 CrIII ions. AC magnetic susceptibility measurements revealed the ferromagnetic transition temperature of 5.5 K for all crystals.T alkaline-earth iron perovskites AFeO3 (A=Ca, Sr, Ba), containing iron in a high valence state of Fe4+ (3d4), have been prepared using high-pressure apparatases to generate strongly oxidizing atmosphere. Recently, however, Hayashi et al. obtained BaFeO3 by heating easily prepared BaFeO2.5 at 200oC in flowing oxygen containing ~10 % of ozone at ambient pressure. This oxide shows ferromagnetism at Tc=111K with a large moment of 3.5 μB/Fe in the presence of an external field of 3 kOe; the magnetic structure at lower fields is a helical structure of the A-type. Our recent study proposed that the material is an interesting candidate for refrigeration based on the magnetocaloric effect (MCE). The ferromagnetism leads to a change of magnetic entropy of 5.8 J kg-1 K-1 and a refrigerant capacity of 170 J kg-1 under an external field of 50 kOe, both being comparable to those of perovskite manganites. The reversibility in both the thermal and magnetic cycles is beneficial to efficient refrigeration. This property arises from the absence of an orbital moment in Fe4+, which is actually in a Fe3+L state (L: ligand hole). In this presentation, the magnetism and MCE of BaFeO3 will be discussed. Also, the author will show Fe-sitesubstitution effects, carried out for the purpose of chemical control of MCE.F bulk (multilayer) two-dimensional (2D) zero-gap state with massless Dirac particles was realized in an organic conductor α-(BEDT-TTF)2I3 under pressure. We have succeeded in detecting the zero-mode Landau level and its spin-split levels in this system probed by inter-layer magneto resistance. The Shubnikov-de Haas oscillations (SdHO) or the quantum Hall effect (QHE), however, have not been observed yet because Fermi level always locates at the Dirac point. Moreover, the multilayered structure makes control of Fermi level by the field-effect-transistor method much more difficult than in the case of graphene.C nanotubes (CNTs) and graphene are considered as prime materials for nanometer-scale science and technology due to their unique and superior combination of electrical, thermal, optical and mechanical properties. This has inspired a widespread effort to develop CNTs and graphene based applications for next generation nanoelectronics. The practical realization of CNT and graphene technology depends critically on whether CNTs can be formed in a controlled manner and if graphene can be produced, modified and patterned into various predesigned architectures in planar (2D) or three dimensional layouts.Dimension Controlled SeH-Assembly of Perylene Based Molecules by Arshad S. Sayyad II Recent advances in the self-assembly of highly organized structures of organic semiconducting molecules by controlled non-covalent interactions has opened avenues for creating materials with unique optical and electrical properties. The main focus of this thesis lies in the synthesis and self-assembly of n-type perylene based organic semiconducting molecules into highly organized materials. Perylene based molecules used in this study are perylene diimide (PTCDI, two side-chains), perylene mono imide (m-PTCI, one side-chain), perylene tetracarboxylic acid (PTCA, no side-chain) and tetraalkali metal salts of PTCA (M4-PTCA, no side-chain), which are synthesized from the parent perylene tetracarboxylic dianhydride (PTCDA). The self-assembly of these molecules have been performed using solution processing methods (dispersion, phasetransfer, and phase-transfer at high temperature) by taking advantage of the changes in solubility of the molecules, wherein the molecular interactions are maximized to favorably allow for the formation of highly organized structures. Dimension control (lD, 2D and 3D structures) of self-assembly has been obtained for different perylene based molecules by appropriate design of the molecule followed by controlling the conditions of assembly. In case of PTCDI, a new solution processing method phase-transfer at high temperature (2L-HT) allowed for the controlled formation of extremely long and fluorescent lD structure. For the m-PTCI molecules theC π-conjugated molecules with three-dimensional (3D) structures have been the subject of intensive research because of not only for their structural beauty but also their many potential applications in molecular electronics. This presentation will cover our recent reports in the synthesis of 3D π-conjugated molecules and the elucidation of their properties. In particular, cycloparaphenylenes (CPPs), which consist benzene rings connected at the para positions, and a ball-like 3D molecule were synthesized based on the platinum-mediated assembly of π-units and subsequent reductive elimination of platinum. Despite extremely high strain of the target molecule, reductive elimination of platinum successfully took place with high efficiency. Several size-dependent properties of CPPs, namely the photophysical and redox properties were also clarified. Theoretical and electrochemical studies suggest that small CPPs and their derivatives should be excellent lead compounds for molecular electronics.This study reports polyhedral oligomeric silsesquioxane (POSS)-based hybrid fibers of architectural hierarchy and compositional heterogeneity. The kinetic arrest of substantial POSS content in the fibers was attributed to rapid solvent evaporation that retarded the phase separation of liquid jet. It provides new insight into the design of novel heterogeneous materials. Polymeric materials of structural hierarchy and compositional heterogeneity have attracted wide interest for their potential applications as biomaterials, photoelectronics, energy storage devices, and surface coatings. Strategies employed to prepare such materials focus mainly on either controlling intermolecular interactions and therefore the nano/microscale assemblies or engineering materials through three-dimensional patterning. Electrospinning, a simple yet versatile technique, has great potential for developing hierarchical materials by manipulating parameters that can control the electrospinning process under non-equilibrium conditions. Strategies that have been employed to introduce structural hierarchy and compositional heterogeneity into electrospun fibers include co-axial electrospinning to produce coresheath or hollow fibers and manipulating the non-equilibrium phase behavior of polymer-based blends or mixtures. In this study, poly(-caprolactone)(PCL)/polyhedral oligomeric silsesquioxane (1-propylmethacrylate)-heptaisobutyl substituted (miBuPOSS, Fig. S1) hybrid fibers with interesting nanopapilla and wrinkled surface features were successfully electrospun from 10:0 to 5:5 by mass PCL/m-iBuPOSS solutions with a fixed PCL concentration of 10 wt% (See Materials and Methods in Supporting Information). Here, PCL, one of the FDA-approved biodegradable and biocompatible polyesters, was used as the matrix polymer. The reactive m-iBuPOSS can be potentially used for incorporating multifunctionality into composite fibers for biomedical applications. It is worth mentioning that uniform POSS-filled fibers have been previously reported for only low loadings of POSS as traditional nanofillers. In contrast, this study reports hybrid fibers with substantial POSS loadings up to 50 wt% (i.e., 5:5 by mass PCL/miBuPOSS blend). Here, the low-surface-energy m-iBuPOSS was used as an essential modulator for the phase separation of the liquid jet along the radial direction. The m-iBuPOSS surface segregation was coupled with rapid solvent evaporation that “froze” PCL chains in the outmost layer prior to drying of the inner phase, which eventually gave rise to a unique fiber architecture composed of a POSS-rich composite crust and a PCL-rich inner phase. When the POSS-rich crust was removed with hexane, the fiber architecture was clearly revealed through a combination of X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD). In comparison to previously reported composite fibers, in which nanostructures were usually used as low-loading nanofillers to achieve compositional uniformity, the PCL/POSS hybrid fibers with substantially high POSS contents reported here exhibit morphological uniformity, structural integrity, architectural hierarchy, and compositional heterogeneity. This study further demonstrates the multifaceted applications of the electrospinning technique for building heterogeneous, hierarchical materials. More importantly, it provides new insight into the effect of rapid solvent evaporation coupled with surface-directed phase separation in the liquid jet and its implications on designing novel heterogeneous materials. Fig. 1 SEM images of hybrid fibers electrospun from solutions with PCL/m-iBuPOSS mass ratios of (A) 10:0, (B) 8:2, (C) 7:3, and (D) 5:5, along with the histograms of fiber-size distributions. Scale bars in SEM images are 4 m (top row) and 1 m (second row). 0 1 2 0 10 20 30 P e rc e n ta g e ( % ) Fiber Diameter (m) 0 1 2 0 10 20 30 P e rc e n ta g e ( % ) Fiber Diameter (m) 0 1 2 0 10 20 30 P e rc e n ta g e ( % ) Fiber Diameter (m) 0 1 2 0 10 20 30 P e rc e n ta g e ( % ) Fiber Diameter (m) D C B A 1 m 4 m Page 1 of 4 RSC Advances R S C A dv an ce s A cc ep te d M an us cr ip t COMMUNICATION Journal Name 2 | J. Name., 2012, 00, 1-3 This journal is