Review

The scope and limitations of using supramolecular interactions to control and direct energy transfer processes in self-assembled materials are discussed with emphasis on recent developments in the field.

In this review, the significant advances of the new type of graphene fibers (GFs) achieved during the recent few years have been systematically summarized, including the tunable and controllable preparation of GFs with functionalizations and their remarkable applications for unconventional devices such as flexible fiber-type of actuators, robots, motors, photovoltaic cells and supercapacitors.

In this review, we discuss diffusion-driven currents in several types of organic-semiconductor diodes, including light-emitting diodes, solar cells and single-carrier devices. It is demonstrated that the ideality factor of the current and photon emission contains important information about charge transport and recombination in such devices. Most importantly, the effects of charge trapping and trap-assisted recombination can be explored. An analytical model is derived for diffusion-driven currents, which can explain the current–voltage behavior of organic diodes and allows determination of the injection barriers and built-in voltages.

Surfaces that display contact angles >150° along with a low contact angle hysteresis for both low and high surface tension liquids are known as superomniphobic surfaces. Such surfaces have several applications, including self-cleaning, non-fouling, stain-free clothing, drag reduction, corrosion prevention and separation of liquids. In this review, we discuss the design criteria, recent studies, applications, challenges and potential of superomniphobic surfaces.

We developed ‘self-oscillating’ polymer gels that undergo spontaneous cyclic swelling–deswelling changes without any on–off switching of external stimuli like a heart muscle. Here, our recent progress on the self-oscillating polymer gels was summarized.

Oil/water separation, especially emulsified oil/water mixture separation, has become a widespread concern because of the severe fouling problem caused by the easy adsorption of oil droplets onto the surfaces of filtration membranes. Many strategies have been employed to eliminate the fouling problem, but it remains a challenge and impedes the development of membrane technology. In this short review, we discuss the recent development of membrane technology for emulsified oil/water separation. As shown in the image, in addition to polymer- and ceramic-dominated traditional membranes, nanomaterial-based membranes have recently demonstrated their superiority and have achieved high performance.

Mesocrystals are superstructures with a crystallographically ordered alignment of nanoparticles and posses unique characteristics such as a high surface area, pore accessibility, and good electronic conductivity and thermal stability. This review summarizes the recent developments of metal oxide mesocrystals in the fields of energy conversion and storage.

Hydrogel-based scaffolds are promising biomaterials to deliver cells and small biomolecules to regenerate the cardiac muscle. It is anticipated that cell-loaded hydrogels will potentially be able to mend the broken heart.

In this review, we highlight the recent achievements in the DNA-programmed self-assembly of homo- and/or hetero-photonic nanoarchitectures comprising gold nanoparticles, gold nanorods and quantum dots in one, two and three dimensions, and overview their optical properties and potential photonic functionalities.

Periodic mesoporous organosilicas (PMOs) are prominent materials for a wide variety of application including catalysis, drug and gene transfer, sensing and imaging, optics, electronic devices, gas sensing, gas adsorption, biomolecule adsorption and chromatographic phases owing to their outstanding pore wall tuning properties. Since each organic molecule in their framework has different chemical behavior, incorporating different organic functionalities into the PMO framework make the materials with unique properties for specific applications. A wide range of PMOs with various bridged organic functionalities and morphologies have been prepared. However, some aspects remain to be studied. The current results and the forthcoming advances in PMOs will make them the materials of excellent for some high-technology applications. PMOs proved to be very useful in a variety of applications, and many others can be envisaged for the near future.

New methods of integrating aptamers with various types of nanomaterials are summarized, highlighting promising classes of aptamer-conjugated nanoparticles for efficient cancer cell recognition and the targeted delivery of drugs. In addition, emerging technologies for cancer treatment using nanomaterials as therapeutic drugs are discussed. These aptamer-conjugated nanomaterials will benefit cancer treatment through increased specificity and efficacy as well as reduced toxicity.

Cerium oxide nanoparticles (CeONPs) have attracted much attention because they possess multi-enzyme mimetic properties and have been used in bioanalysis, biomedicine, drug delivery, bioscaffold and so on. This review summarizes recent achievements on CeONPs catalytic mechanisms, the multi-enzyme-like activity, and their biomedical applications, such as in treatment of cancer, diabetes and Alzheimer’s disease.

Various spherical nanocarbon materials, including fullerenes, carbon nanohorn aggregates, nanodiamonds etc., have shown potential anti-cancer effects. Fullerenes and metallofullerenes possess outstanding ROS-scavenging capability, as well as other biological effects like immunity enhancement etc., affording promising tumor suppression potential. Carbon nanohorn aggregates and nanodiamond particles have demonstrated effective drug delivery ability for cancer therapy. Moreover, it is noteworthy that these spherical nanocarbon materials show positive toxicological evaluation results, encouraging possible practical usage for biomedical applications.

The hierarchical self-organization of appropriately functionalized disc-shaped molecules leads to the formation of discotic liquid crystals (DLCs). Columnar phases formed by these intriguing materials are emerging as one-dimensional organic semiconducting materials. Recently, their hybridization with various metallic and semiconducting nanoparticles has been realized to alter and improve their properties. This article provides an overview on the development in the field of newly immersed discotic nanoscience, a sub-field of liquid crystal (LC) nanoscience.

The chiral liquid crystalline self-organization of cellulose nanocrystals into helical arrangements, giving the resulting materials photonic crystal properties and enhanced mechanical behavior, are comprehensively summarized and compared with other rod-like nanoparticles, for example, carbon nanotubes and fd virus. The consequences of the sensitive balance between liquid crystal formation and glass/gel formation are discussed in detail, in particular regarding the development toward control of helix pitch and orientation. Important topics for future studies are identified and suggestions for novel applications are made.

Upconversion nanophosphors have unique ability to generate anti-Stokes luminescence. The rapid developments of nanotechnology in recent years have demonstrated the successful synthesis and optimization of such upconversion nanophosphors. This review summarizes the recent advances using upconversion nanophosphors as bioprobe for in vivo applications.

Seven years ago, Wilma Eerenstein, Neil Mathur and Jim Scott published a Venn diagram (above) showing the overlap of piezoelectricity, ferroelectricity (green circle), ferromagnetism (black circle), and magnetoelectricity (blue hatched center circle); and soon thereafter Manuel Bibes put into each sector the crystals which were thought to belong. The overlap region between green and black are multiferroic ferromagnetic-ferroelectrics. Not all were correct; BiMnO₃ is NOT ferroelectric. Of these materials, only Cr₂O₃ and BiFeO₃ function at room temperature (or are magnetoelectric, and the former is neither a ferromagnet nor ferroelectric). Today’s review is an update on the new multiferroic and/or magnetoelectric materials that function at or near ambient temperatures and pressures: Cupric oxide (not actually magnetoelectric), iron magnesium hexaferrites, and perovskite oxides based upon PbTiO₃.

Metal chalcogenide quantum dots (QDs) and lead halide perovskites are two types of prospective light harvesters for mesoscopic solar cells. The two most promising QD sensitizers are PbS and Sb₂S₃, for which the PCEs of their corresponding QDSCs have attained ∼7% in 2012. In 2013, the performance of a TiO₂ solar cell sensitized with lead-iodide perovskite (CH₃NH₃PbI₃) was optimized to attain an overall power conversion efficiency of 15%, which is a new milestone for solar cells of this type, with a device structure similar to that of a dye-sensitized solar cell.

Plasmonic photoelectric conversion from visible to near-infrared wavelengths has been successfully demonstrated using electrodes in which gold nanorods are elaborately arrayed on a titanium dioxide (TiO₂) single crystal. Importantly, water molecules serve as the electron donor in the plasmonic photoelectric conversion system. Therefore, the stoichiometric evolution of oxygen and hydrogen peroxide as a result of the four- or two-electron oxidation of water molecules was accomplished even at near-infrared wavelengths, enabling the application of this plasmonic photoelectric system in artificial photosynthesis processes responding to a wide range of solar wavelengths.

Over the last decade, metal oxides have proven to be important materials for organic electronics. Oxides are often used as charge-injection and charge-selective interlayers to engineer the electrical resistance at electrode/organic interfaces in organic devices. An oxide’s behavior as an interlayer depends strongly on the oxide’s electronic properties—such as its band structure and work function. The numerous degrees of freedom in an oxide’s electronic properties allow these characteristics to be easily modified. The present review outlines the use of metal oxides in organic electronics, and discusses the factors that affect the oxide’s properties that are relevant to oxide/organic interfaces.