This work presents a novel and facile method for fabricating paper-based microfluidic devices by means of coupling of hydrophobic silane to paper fibers followed by deep UV-lithography. After filter paper being simply immersed in an octadecyltrichlorosilane (OTS) solution in n-hexane for 5 min, the hydrophilic paper became highly hydrophobic (water contact angle of about 125°) due to the hydrophobic OTS molecules were coupled to paper's cellulose fibers. The hydrophobized paper was then exposed to deep UV-lights through a quartz mask that had the pattern of the to-be-prepared channel network. Thus, the UV-exposed regions turned highly hydrophilic whereas the masked regions remained highly hydrophobic, generating hydrophilic channels, reservoirs and reaction zones that were well-defined by the hydrophobic regions. The resolution for hydrophilic channels was 233 ± 30 μm and that for between-channel hydrophobic barrier was 137 ± 21 μm. Contact angle measurement, X-ray photoelectron spectroscopy (XPS) and attenuated total reflectance Fourier transform-infrared (ATR-FT-IR) spectroscopy were employed to characterize the surface chemistry of the OTS-coated and UV/O(3)-treated paper, and the related mechanism was discussed. Colorimetric assays of nitrite are demonstrated with the developed paper-based microfluidic devices.

With the rapid development of biotechnology and nanomedicine, extensive research has focused on the investigations of delivering large-cargo molecules using nanoparticles through the cell membrane for disease diagnosis and treatment. Various inorganic and polymeric nanoparticles with optimized surface properties have been developed to carry these active cargo molecules such as organic molecules, oligonucleotides and proteins. Phagocytosis and pinocytosis have been suggested as the two major uptake mechanisms for nanoparticles to enter into cellular interior, but such mechanisms are still under debate. In order to enhance the efficiency of cellular uptake of nanoparticles and further understand the physiological process, it is important to investigate detailed interaction mechanisms between nanoparticles and cell membranes. Here, we will review the recent advances of the effect of nanoparticle properties (e.g., nanoparticle shape, size, charge, surface modification, etc.) on cellular uptake mechanisms. These will aid in the future design and development of nanoparticles with improved surface properties for drug and biomolecule delivery. Up to now, novel analytical techniques have been used to examine nanoparticle-cell membrane interactions, but their detailed uptake mechanisms and pathways still need more in-depth research. It is suggested that developing appropriate analytical techniques to study cellular uptake mechanisms of nanoparticles in real time is urgently desired.

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The practical applications of Li-ion batteries (LIBs) are challenged by their safety concerns when using liquid electrolytes (LEs). Solid-state gel polymer electrolytes (GPEs) can address this challenge and have drawn increased attention recently. Normally, GPEs are prepared separately and then assembled into cells, which undoubtedly result in dissatisfactory solid/solid interfacial compatibility and low ionic conductivity. Fortunately, in situ GPEs are proposed to address the above challenges and simplify the preparation process. Typically, LE precursor is injected into the cells and gradually transformed into a quasisolid gel state under the conditions of thermal or chemical initiators. Consequently, the obtained in situ GPEs could fully infiltrate the electrode and better interface contact of gel electrolyte/electrode is thus inherited. In this review, the authors focus on the in situ GPEs used in lithium batteries (LBs), and summarize recent progress of the design, synthesis, and applications of in situ GPEs. Based on the different ways of triggering polymerization, there are mainly three methods: thermochemical gelation, polymerization by additional chemical initiators, and cross-linking initiated by Li O bond. Composite GPEs based on in situ solidification method are introduced as a promising strategy to improve the electrochemical performances. Finally, up-to-date research progresses are discussed, and perspectives are provided on the development and challenges of in situ GPEs to meet the requirements for their practical applications in LBs.

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The interfacial region plays a critical role in determining the electrical properties of dielectric nanocomposites. The current state-of-the-art interfacial modification is predominantly based on utilizing flexible organic molecules, which are random polymer coils and generally collapse on the surface of any modified nanoparticles. This work focused on engineering the interfacial region between Na 2 Ti 3 O 7 nanofibers and polymer matrix and, for the first time, utilized the liquid-crystalline polymer poly{2,5-bis[(4methoxyphenyl)oxycarbonyl]styrene} (PMPCS) to modulate the interface where the rigid polymer was forced to form a straight conformation. Owing to the rigidity and orientation of PMPCS, a series of core−shell structured Na 2 Ti 3 O 7 @PMPCS nanofibers with finely tuned shell thickness were prepared. The prepared Na 2 Ti 3 O 7 @PMPCS/P(VDF-HFP) nanocomposites showed significantly different permittivity from 10.7 to 69.6 at 1 kHz with the gradient thicknesses of PMPCS shell. These results effectively proved that modulating the interfacial layer thickness in the dielectrics nanocomposites is also a method to modulating the dielectric property.

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