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We report herein a series of tetrablock-mimic azobenzene-containing [60]fullerene dyads that form supramolecular liquid crystals (LCs) from phase-segregated two-dimensional (2D) crystals. The unique double-, triple-, and quadruple-layer packing structure of fullerenes in the 2D crystals leads to different smectic supramolecular LC phases, and novel LC phase transitions were observed upon changes in the fullerene packing layer number in the 2D crystals. Interestingly, by combining the LC properties with 2D crystals, these materials show excellent electron mobility in the order of 10-3 cm2 V-1 s-1 , despite their relatively low fullerene content. Our results provide a novel method to manipulate 2D crystal layer thickness, with promising applications in optoelectronic devices.

In recent decades, extensive studies have been devoted to assembling nanoparticles (NPs) into various ordered structures to achieve novel optical properties. However, it still remains a challenging task to assemble NPs into cyclic one-dimensional (1D) shapes, such as rings and frames. Herein, we report a directed assembly method to precisely assemble NPs into well-defined, free-standing frames using polymer single crystals (PSCs) as the template. Preformed poly(ethylene oxide) (PEO) single crystals were used as the template to direct the crystallization of block copolymer (BCP) poly(ethylene oxide)-b-poly(4-vinylpyridine) (PEO-b-P4VP), which directs the gold NPs (AuNPs) to form AuNP frames. By controlling the PSC growth, we were able to, for the first time, precisely tune both the size and width of the AuNP frame. These novel AuNP frames topologically resemble NP nanorings and cyclic polymer chains, and show unique surface plasmon resonance (SPR) behaviors.

The electron-doping-induced phase transition of a prototypical perovskite SmNiO3 induces a large and non-volatile optical refractive-index change and has great potential for active-photonic-device applications. Strong optical modulation from the visible to the mid-infrared is demonstrated using thin-film SmNiO3 . Modulation of a narrow band of light is demonstrated using plasmonic metasurfaces integrated with SmNiO3 .

Solid polymer electrolytes (SPEs) with tunable network structures are prepared by a facile one-pot reaction of polyhedral oligomeric silsesquioxane (POSS) and poly(ethylene glycol) (PEG). These SPEs with high conductivity and high modulus exhibit superior lithium dendrite growth resistance even at high current densities. Measurements of lithium metal batteries with a LiFe—PO4 cathode show excellent cycling stability and rate capability. Also disclosed are products made by the process of the invention and batteries including such products.

Janus hairy nanoparticles (JHNPs) represent a new class of hybrid materials with a nanoparticle core and a layer of bicompartmentalized polymer brushes. This unique structure combines the complex properties of polymer brushes, the amphiphilic nature of surfactant, and the mechanical, optical, and electronic properties of nanoparticles. Over the past decade, tremendous efforts have been devoted to synthesizing JHNPs and understanding their structure and properties. In this review, we will summarize the recent progresses in the field, including fabrication approaches and the self- and directed assembly behavior of such JHNPs. We will specifically focus on the newly developed polymer single crystal directed nanoparticle assembly approach. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1620–1640

The diffusion of nanoparticles at a water-alkane interface is studied using fluorescence correlation spectroscopy. Hydrophilic and hydrophobic quantum dots of 5, 8, and 11 nm radius are used. A slow-down of nanoparticle diffusion at the liquid-liquid interface is observed. The effect is most evident when the viscosities of both liquid phases are similar, here, at the water-decane interface. In this case, the interfacial diffusion coefficients of the hydrophilic particles are 1.5 times and those of the hydrophobic particles 2 times lower than the corresponding bulk values.

Top-selective surface modification has been widely used for the synthesis of Janus nanoparticles (NPs). Herein we demonstrate that polymer single crystals can serve as generic substrates to immobilize NPs and the resultant NPs are Janus in nature. This technique is generic because various NPs as well as polymer single crystal substrates can be used. Single crystals of poly(ethylene oxide), polycaprolactone, and polyethylene-block-poly(ethylene oxide) have been successfully used to immobilize gold, magnetic, and semiconducting NPs. Subsequent dissolution of the single crystals led to various types of Janus NPs and NP clusters with different polymer brushes.

We report on the synthesis of a thermosensitive polymer brush-supported 4-N,N-dialkylaminopyridine catalyst and the comparison of its catalytic activity with the corresponding linear polymer-supported version in the hydrolysis of p-nitrophenyl acetate (NPA) as well as the effect of lower critical solution temperature (LCST) transition on catalytic activity. The polymer brushes were synthesized from initiator-functionalized silica particles by surface-initiated atom transfer radical polymerization of methoxytri(ethylene glycol) methacrylate and 2-(N-methyl-N-(4-pyridyl)amino)ethyl methacrylate in the presence of a free initiator. Dynamic light scattering studies showed that the onset temperatures of the LCST transition of polymer brushes in pH 7.52 and 7.82 buffers were 42 and 38 °C, respectively. Under the same reaction conditions, the net initial rate of the hydrolysis of NPA catalyzed by hairy particles was 70–80% of that catalyzed by the free copolymer at the temperature below the LCST of polymer brushes. With further increasing the temperature above the LCST, the plot of logarithm of net initial rate versus inverse temperature exhibited a shift for the reactions catalyzed by hairy particles and leveled off or decreased slightly in the case of using the free copolymer as catalyst, presumably because the structures of the aggregates of hairy particles and free copolymer chains were different. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2853–2870, 2009

Ultraviolet (UV) polymerizable discotic liquid-crystalline (DLC) molecules (2,3,6,7,10,11-hexakis(4′-acryloy-m-alkyloxybenzoyoxy)triphenylene [HAHBT-m, where m was the number of methylene units, and here m = 6 (HAHBT-6)]) were assembled to form a negative retardation film with an oblique optical axis on a specifically designed rubbing-aligned polyimide layer surface [6FDA-11CBBP (where 11 is the number of methylene units in the side chains)]. The side chains of this polyimide were terminated by cyanobiphenyl groups. Surface-enhanced Raman scattering (SERS) and optical second harmonic generation results showed that rubbing caused a surface structural re-arrangement in the alignment layer resulting in a negative pre-tilt angle (θs) of –8.5° (which was in the direction opposite to the rubbing direction). The molecular topology at the rubbed surface was governed by a stable fold-like bent structure of the cyanobiphenyl side chains, in which the CN groups preferentially pointed down towards the surface. When the DLC molecules were deposited onto the alignment surface and polymerized via UV irradiation to generate a new optical film, an oblique optical axis with an average tilt angle of –18.6° with respect to the film normal was detected using ellipsometric measurements. This tilted optical axis was developed by the DLC molecules being wedged on top of the cyanobiphenyl groups when in the bent conformation. Furthermore, the tilt angle difference between the θs at the alignment surface and at the air interface of the DLC molecules was attributed to a splay deformation of the DLC molecules along the film surface normal. Optical modeling has also confirmed our experimental observations.

The behavior of vulnerable atherosclerotic plaques is believed to be closely related to plaque composition. There is a need for an effective in vivo technique for examining plaque constituent properties. In this study, Fourier transform infrared spectroscopy using attenuated total reflectance (FTIR-ATR) was used to assess and analyze the biochemical properties of human atherosclerotic plaques. FTIR spectra clearly revealed prominent spectral features corresponding to plaque constituents of interest: the 2930 cm−1 and 2850 cm−1 peaks (indicating the presence of lipids), the 1730 cm−1 peak (lipid esters), the 1550 cm−1 and 1650 cm−1 peaks (fibrous tissues), and the 1100–1000 cm−1 broad phosphate peak (calcification). Spectral data examined on a qualitative basis correlated well with both gross tissue anatomy and histologic features. Gross spatial mappings of tissue sections of both lipidic and calcified plaques were performed. Spectra from various regions of the plaques demonstrated the evolution of lipid peaks, fibrous tissue peaks, and the phosphate calcification band within the plaques. Histologic analysis corroborated the spectral findings in this study. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 64A: 197–206, 2003

Solid polymer electrolytes have shown to be a promising solution to suppressing dendrite growth for safer and higher performance lithium batteries. This article reports the fabrication and characterization of a series of nanostructured polymer electrolyte membranes (PEMs) comprised of poly(ethylene glycol)/bis(trifluoromethane)sulfonimide lithium electrolyte and acrylate–thiol-ene crosslinked resin using a holographic polymerization (HP). Nanoscale long-range order is observed and this unique structure imposes intriguing mechanical and ion-conducting properties of the PEMs. The modulus of the holographically polymerized PEMs can be tuned to vary from 150 to 1300 MPa while room temperature conductivities of ≈2 × 10−5 S cm−1 and 90 °C conductivity of ≈5 × 10−4 S cm−1 are achieved. The HP nanostructure is also capable of directing ion transport either parallel or perpendicular to the membrane surface; an unprecedented ionic conductivity anisotropy as high as 3 × 105 is achieved. It is anticipated that these PEMs may be excellent candidates for lithium battery applications.

Solid polymer electrolytes (SPEs) are desirable in lithium metal batteries (LMBs) since they are nonflammable and show excellent lithium dendrite growth resistance. However, fabricating high performance polymer LMBs is still a grand challenge because of the complex battery system. In this work, a series of tailor-designed hybrid SPEs are used to prepare LMBs with a LiFePO4-based cathode. High performance LMBs with both excellent rate capability and long cycle life are obtained at 60 and 90 °C. The well-controlled network structure in this series of hybrid SPEs offers a model system to study the relationship between the SPE properties and the LMB performance. It is shown that the cycle life of the polymer LMBs is closely correlated with the SPE–Li interface ionic conductivity, underscoring the importance of the solid electrolyte interface in LMB operation. LMB performance is further correlated with the molecular network structure. It is anticipated that results from this study will shed light on designing SPEs for high performance LMB applications.

Carbon nanotube (CNT)-seeded controlled polymer crystallization provides a simple yet effective means to periodically modify CNT surfaces in work reported by Li and co-workers on p. 1198. The cover shows CNTs periodically decorated with polyethylene single crystals, with a periodicity of ∼50–70 nm. Both single- and multiwalled CNTs have been successfully decorated with polyethylene and Nylon 6,6, implying that coupling crystalline polymers with functional groups might be a generic method for CNT functionalization in an ordered and controlled manner.