Functionalized metal‐organic polyhedra hybrid membranes for aromatic hydrocarbons recovery

Pervaporation membranes are potentially useful in the separation of aromatic/aliphatic mixtures. Wherein, the membrane material plays a key role. Herein, a series of functionalized metal‐organic polyhedra (MOPs)/hyperbranched polymer hybrid membranes are molecularly designed and fabricated for the recovery of aromatic hydrocarbons. The isostructural MOP molecules with different functional groups are uniform in shape/size and soluble in solvents, which enable them to disperse well and be compatible in/with the polymer. Pervaporation results demonstrated significant improvements of these membranes in separation performances. Particularly, the membrane with MOP‐SO₃Na_nH_m showed the separation factor of 8.03 and the permeation flux of 528 g/m²h for the recovery of toluene from its 50 wt % n‐heptane mixture, and those values are 8.4 and 540 g/m²h for benzene/cyclohexane mixture. We propose that the selectivity of these membranes is affected primarily by the polarity of functional groups in MOPs, which were further explained by the adsorption experiments and molecular simulations. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3706–3716, 2016     

Functionalized chitosan with super paramagnetic hybrid nanocarrier for targeted drug delivery of curcumin

Recently, hydrophobically functionalized polymers have been deployed as carriers to improve the encapsulation of hydrophobic drugs. The metal nanocomposites are extensively used to improve the biocompatibility of the formulation and target the drug to the specialized site. In our current study, naphthalene acetate (NAA) was incorporated into the amine group of chitosan to form a hydrophobically functionalized chitosan–NAA drug delivery carrier. The calcium ferrite nanoparticles (CFNP) were embedded in the chitosan–NAA matrix to form a super paramagnetic hybrid nanocarrier for controlled curcumin drug delivery. Various analytical techniques were performed to ensure the functional group modifications, thermal stability, surface nature and morphological behavior of synthesized hybrid carriers. The maximum encapsulation efficiency of 93.6% was obtained under the optimized conditions of drug to chitosan–NAA at 0.1, CFNP to chitosan–NAA at 0.75 and TPP to chitosan–NAA at 1.0 (w/w) ratios, respectively, by adapting Taguchi method. Drug release studies were conducted to determine the effect of pH, drug loading concentrations and magnetic field responses. The drug release data were fitted to various kinetic release models to understand the drug release mechanism. The biocompatibility of the hybrid material was tested using L929 mouse fibroblast cells. The cytotoxicity test against breast cancer cells (MCF-7) was also performed to study the anticancer property of the hybrid paramagnetic material. The prepared curcumin-loaded chitosan–NAA/CFNP was very active against cancer cells in comparison to the normal cells. The results confirmed the applicability of the hybrid nanocarriers in cancer cell-targeted drug delivery.     

Synthesis of polymeric and hybrid nanoparticles for electroplating applications

Monodisperse polymeric particles with diameters in the range of 60-1400 nm were prepared by (emulsifier-free) emulsion polymerization and incorporated into electrolytic zinc coatings aiming to improve the corrosion resistance of electrogalvanized steel. Various types of polymeric nanoparticles were thus synthesized in order to assess the effect of the emulsifier, initiator and comonomer type on the particle morphology, stability and codeposition behavior. The polymerization experiments were carried out in laboratory-scale glass reactors and the most promising recipes were successfully scaled-up in a fully automated pilot-scale reactor. Replicates of some representative experiments, which were run both in lab and pilot-scale reactors, indicated excellent reproducibility of the polymerization process. Uniform, polymer-containing zinc coatings were produced by electrolytic codeposition of the nanoparticles from an acid zinc plating bath using a rotating disk electrode (RDE). Hybrid polystyrene/silica nanoparticles with increased silica content were also prepared via emulsifier-free emulsion polymerization, in the presence of an ultrafine aqueous silica sol, to be used in electrocoating applications. The effect of key process parameters, such as initial monomers molar ratio and pH on the size, morphology and silica content of the produced hybrid nanoparticles was investigated.     

Single-step assembly of polymer-lipid hybrid nanoparticles for mitomycin C delivery

Mitomycin C is one of the most effective chemotherapeutic agents for a wide spectrum of cancers, but its clinical use is still hindered by the mitomycin C (MMC) delivery systems. In this study, the MMC-loaded polymer-lipid hybrid nanoparticles (NPs) were prepared by a single-step assembly (ACS Nano 2012, 6:4955 to 4965) of MMC-soybean phosphatidyhlcholine (SPC) complex (Mol. Pharmaceutics 2013, 10:90 to 101) and biodegradable polylactic acid (PLA) polymers for intravenous MMC delivery. The advantage of the MMC-SPC complex on the polymer-lipid hybrid NPs was that MMC-SPC was used as a structural element to offer the integrity of the hybrid NPs, served as a drug preparation to increase the effectiveness and safety and control the release of MMC, and acted as an emulsifier to facilitate and stabilize the formation. Compared to the PLA NPs/MMC, the PLA NPs/MMC-SPC showed a significant accumulation of MMC in the nuclei as the action site of MMC. The PLA NPs/MMC-SPC also exhibited a significantly higher anticancer effect compared to the PLA NPs/MMC or free MMC injection in vitro and in vivo. These results suggested that the MMC-loaded polymer-lipid hybrid NPs might be useful and efficient drug delivery systems for widening the therapeutic window of MMC and bringing the clinical use of MMC one step closer to reality.     

Functionalized self-assembled monolayers on mesoporous silica nanoparticles with high surface coverage

ABSTRACT: Mesoporous silica nanoparticles (MSNs) containing vinyl-, propyl-, isobutyl- and phenyl functionalized monolayers were reported. These functionalized MSNs were prepared via molecular self-assembly of organosilanes on the mesoporous supports. The relative surface coverage of the organic monolayers can reach up to 100% (about 5.06 silanes/nm.     

纳米材料用于改性水处理中的有机-无机杂化膜的研究进展

通过将亲水性的纳米粒子加入有机高分子膜的制备中得到的有机-无机杂化膜结合了无机膜和有机膜的优点,成为膜技术领域的研究热点之一。在制膜过程中引入的纳米粒子主要包括ZrO_2、TiO_2、Al2O3、SiO_2、石墨烯等,主要通过3种不同方法:无机纳米颗粒可直接加入铸膜液、复合纳米粒子改性、纳米粒子前驱体改性制备有机-无机杂化膜。从理论与应用两个角度对有机-无机杂化膜在提高物理和化学稳定性、分离性能,膜亲水性以及抗污染性能等方面进行了阐述,归纳了有机-无机杂化膜在水处理领域的应用效果以及最新研究进展,并针对杂化膜研究提出了一些建议。     

纳米材料用于改性水处理中的有机-无机杂化膜的研究进展

通过将亲水性的纳米粒子加入有机高分子膜的制备中得到的有机-无机杂化膜结合了无机膜和有机膜的优点,成为膜技术领域的研究热点之一。在制膜过程中引入的纳米粒子主要包括ZrO_2、TiO_2、Al2O3、SiO_2、石墨烯等,主要通过3种不同方法:无机纳米颗粒可直接加入铸膜液、复合纳米粒子改性、纳米粒子前驱体改性制备有机-无机杂化膜。从理论与应用两个角度对有机-无机杂化膜在提高物理和化学稳定性、分离性能,膜亲水性以及抗污染性能等方面进行了阐述,归纳了有机-无机杂化膜在水处理领域的应用效果以及最新研究进展,并针对杂化膜研究提出了一些建议。     

From ligand-stabilized gold nanoparticles to hybrid organic-inorganic superstructures

Gold nanoparticles (Au NPs) have many potential applications including nanoelectronics, catalysts and sensors. These future devices depend on stable and monodisperse NPs and their directed assembly. Herein we review our efforts to develop oligomeric thioether ligands able to direct the synthesis of Au NPs and their surface functionalization. A screening of different oligomeric thioethers indicates that the NPs become more stable and monodisperse with increasing length of the thioether oligomer. The heptameric benzylic thioether 4 stabilizes monodisperse NPs with a diameter of 1 nm and excellent long-term stability in solution. It is further monofunctionalized with a central protected acetylene. After NP formation in the presence of the ligands we utilize the peripheral functionality to interlink the NPs. A mild oxidative diacetylene coupling protocol is used to covalently bind these 'artificial molecules'. This wet-chemical procedure leads to the formation of hybrid organic-inorganic superstructures.     

Suspended hybrid films assembled from thiol-capped gold nanoparticles

ABSTRACT: In this work, we explored the formation processes of suspended hybrid thin films of thiol-capped Au nanoparticles (AuNPs) inside metal oxide tubular structures. We found that a balance between in-film interactions of the AuNPs and boundary interactions with metal oxides is a key in making these special organic-inorganic thin films. The hybrid films process many processing advantages and flexibilities, such as controllable film thickness, interfacial shape and inter-AuNPs distance, tuning of particle sizes, thiol population, chain lengths, and other new properties by introducing functional groups to thiol chains. Among their many unique features, the assembly-disassembly property may be useful for future on-off or store-release applications.     

Functionalized gold nanoparticles: a detailed in vivo multimodal microscopic brain distribution study

In the present study, the in vivo distribution of polyelectrolyte multilayer coated gold nanoparticles is shown, starting from the living animal down to cellular level. The coating was designed with functional moieties to serve as a potential nano drug for prion disease. With near infrared time-domain imaging we followed the biodistribution in mice up to 7 days after intravenous injection of the nanoparticles. The peak concentration in the head of mice was detected between 19 and 24 h. The precise particle distribution in the brain was studied ex vivo by X-ray microtomography, confocal laser and fluorescence microscopy. We found that the particles mainly accumulate in the hippocampus, thalamus, hypothalamus, and the cerebral cortex.     

Architecture of colloidal crystals constructed by silica hybrid nanoparticles

Silica (SiO₂)‐crosslinked polystyrene (PS) particles possessing photofunctional N,N‐diethyldithiocarbamate (DC) groups on their surface were prepared by the free‐radical emulsion copolymerization of a mixture of SiO₂ (diameter D_n = 192 nm), styrene, divinyl benzene, 4‐vinylbenzyl N,N‐diethyldithiocarbamate (VBDC), and 2‐hydroxyethyl methacrylate with a radical initiator under UV irradiation. In this copolymerization, the inimer VBDC had the formation of a hyperbranched structure by a living radical mechanism. These particles had DC groups on their surface. Subsequently, poly(methyl methacrylate) brushes encapsulated SiO₂ particles were synthesized by the grafting from a photoinduced atom transfer radical polymerization (ATRP) approach of methyl methacrylate initiated by SiO₂‐crosslinked PS particles as a macroinitiator. We constructed the colloidal crystals using these photofunctional particles. Moreover, the SiO₂ particle array of colloidal crystals was locked by radical photopolymerization with vinyl monomer as a matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Palladium metal nanoparticles on organically modified thin hybrid films

Hybrid thin films containing palladium nanoparticles in different concentrations (0.5% and 1%) with and without nanoparticle stabiliser agent [mercaptopropyl trimethoxysilane, MPTMS] were prepared using a sol–gel process. Pd nanoparticles were found to be highly dispersed on the thin films with particles ranging from 7 to 10 nm. The catalytic properties of the thin films supported Pd nanoparticles were investigated in the Heck reaction of iodobenzene and methyl acrylate. Films containing Pd MNP (with and without MPTMS) gave quantitative conversion and complete selectivity to the targeted product (methyl cinnamate) in a short time of reaction (<15 min) under microwave irradiation. While Pd containing films without MPTMS were highly active and reusable after 3 runs, MPTMS containing films were found to be inactive after the first use. Such phenomenon was correlated to the steric hindrance round the Pd MNP due to the adsorption of species on the surface that render the catalysts inactive.     

Development of the inorganic nanoparticles reinforced alginate-based hybrid fiber for wound care and healing

It is necessary for wound dressing constructed from fibers capable of overcoming external stretching and protecting injured skin. The limited mechanical performance of existing alginate fiber limits its biomaterial application. Herein, this issue can be addressed via incorporation of uniformly dispersed hydroxyapatite (HAP) and silica (SiO₂) nanoparticles (NPs) in alginate (Alg) by microfluidic spinning technique. These NPs serve as a reinforcing phase to help the alginate-based composite to develop outstanding mechanics. Both HAP-Alg and SiO₂-Alg hybrid fibers exhibited excellent breaking elongation, 67.56 ± 6.85% and 52.08 ± 5.20% respectively, while that of breaking strength were 7.04 ± 0.58 MPa and 4.96 ± 0.59 MPa. Furthermore, in vitro cytotoxicity was explored by studying on the proliferation and migration of keratinocytes and fibroblasts, which illustrated no obvious cytotoxicity of the resulting alginate fibers loaded with HAP and SiO₂ NPs. The artificial scratch assay demonstrated that the resulting alginate-based composite fiber can assist the injured skin regeneration. This work provides a significant progress in the conception of developing NPs reinforced alginate-based hybrid fiber which can withstand the large strain behavior and facilitate wound healing, making it an ideal candidate as wound dressings and fibrous scaffolds.     

Functionalized DNA Nanostructures for Nanomedicine

DNA nanotechnology utilizes synthetic DNA strands as the building material to construct nanoscale devices, and the field has developed rapidly over the past decade. Recently, the use of DNA nanostructures for various applications, particularly biomedical ones, has drawn great interest. This review focuses on the most recent research directed at utilizing functionalized DNA devices for nanomedical applications and presents representative research progress in disease diagnosis, treatment and prevention. In addition, the safety and future clinical applications of DNA nanostructures are discussed.     

Facile synthesis and optical properties of polymer-laced ZnO-Au hybrid nanoparticles

Bi-phase dispersible ZnO-Au hybrid nanoparticles were synthesized via one-pot non-aqueous nanoemulsion using the triblock copolymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) as the surfactant. The characterization shows that the polymer-laced ZnO-Au nanoparticles are monosized and of high crystallinity and demonstrate excellent dispersibility and optical performance in both organic and aqueous medium, revealing the effects of quantum confinement and medium. The findings show two well-behaved absorption bands locating at approximately 360 nm from ZnO and between 520 and 550 nm from the surface plasmon resonance of the nanosized Au and multiple visible fingerprint photoluminescent emissions. Consequently, the wide optical absorbance and fluorescent activity in different solvents could be promising for biosensing, photocatalysis, photodegradation, and optoelectronic devices.     

Enhancing the fraction of grafted polystyrene on silica hybrid nanoparticles

Polymer-grafted inorganic nanoparticles are being developed for a diverse array of applications, ranging from drug delivery to multifunctional composites. In many instances, performance of these core-shell hybrids is limited by relatively broad distributions of size and composition, as well as the presence of impurities, such as unattached polymer chains. Herein, further synthetic improvements, and associated characterization techniques, to enhance the fraction of the grafted polystyrene shell on silica hybrid nanoparticles are discussed. We found that during surface-initiated atom transfer radical polymerization (SI-ATRP) from the silica nanoparticles, thermal self-initiation of styrene produces unattached polymer chains. Size exclusion chromatography afforded a facile approach to quantify the mass of the unattached polymer, and provide a substantial refinement to estimates of chain graft density beyond traditionally-used approaches, such as thermogravimetry. This fraction of unattached polymer is still present even after post-polymerization work-up via precipitation and re-dissolution. Removal necessitates additional procedures, such as high speed centrifugation. Selection of a lower polymerization temperature, in concert with a more reactive Cu complex, significantly reduces the amount of unattached polystyrene impurity. The improved polymerization conditions and post-polymerization purification provide more refined polystyrene-grafted silica nanoparticles to clarify structure-property relationships of these core-shell hybrids.     

有机-无机杂化核壳型乳胶粒的制备及其粒径控制

以苯乙烯乳液聚合合成种子,再在种子外生成苯乙烯与甲基丙烯酸-3-三甲氧基硅丙酯（MPS）的共聚物,利用MPS中硅氧烷基的水解-缩合反应,形成交联的壳,得到有机-无机杂化型核壳乳胶粒.然后用溶剂将聚苯乙烯模板溶解,可得到空心微胶囊.通过透射电镜（TEM）和动态光散射粒径仪（DLS）观测乳胶粒及微胶囊的形态.并研究了乳化剂种类、介质pH值、MPS用量和加入方式对粒径、粒子数和体系稳定性的影响.发现非离子型乳化剂、酸性或碱性介质、MPS用量过多均促进乳胶粒子数减少,减弱了乳液稳定性.而采取连续滴加MPS的方法则可提高乳液的稳定性,且粒径可控.     

Functionalized organic nanoparticles from core-crosslinked poly(4-vinylbenzocyclobutene-b-butadiene) diblock copolymer micelles

Surface-functionalized polymeric nanoparticles were prepared by: a) self-assembly of poly(4-vinylbenzocyclobutene-b-butadiene) diblock copolymer (PVBCB-b-PB) to form spherical micelles (diameter: 15-48 nm) in decane, a selective solvent for PB, b) crosslinking of the PVBCB core through thermal dimerization at 200-240 °C, and c) cleavage of the PB corona via ozonolysis and addition of dimethyl sulfide to afford aldehyde-functionalized nanoparticles (diameter: ∼16-20 nm), along with agglomerated nanoparticles ranging from ∼30 to ∼100 nm in diameter. The characterization of the diblock copolymer precursors, the intermediate micelles and the final surface-functionalized crosslinked nanoparticles was carried out by a combination of size exclusion chromatography, static and dynamic light scattering, viscometry, thermogravimetric analysis, ¹H NMR and FTIR spectroscopy and transmission electron microscopy.