Journal of Colloid and Interface Science

Photochlorination method was used to engineer the structural defects and covalent CCl bonds in graphene. Cl coverage of 18 atom% was successfully confirmed by X-ray photoelectron spectroscopy, and D, G and 2D peaks changes upon irradiation were monitored by Raman. The mobility of chlorinated graphene field-effect transistor decreased to 66.1 cm2 /(V s) in comparison to pristine graphene of 730.4 cm2 /(V s). Raman indicated that the defects and CCl bonds are sensitively associated with the irradiation time, thus the structural defects and composition can be engineered accordingly...

It was experimentally shown that a depinning force of a receding droplet on a micropillared superhydrophobic surface has an apparently linear correlation with the maximal three-phase contact line attainable along an actual droplet boundary. However, the experimental observation has not yet been supported by any theoretical basis or analysis. This study establishes an analytical model that theoretically supports the experimental observation on the basis of the dynamics of a contact line. The depinning force of a receding droplet was experimentally measured in evaporation on micropillared superhydrophobic surfaces with varying structure pitches but a fixed size...

Contact lenses (CL) provide visual correction but their use may also induce several adverse effects causative of discomfort and conditions that lead to stop or discontinue their use. Discomfort is mainly caused by insufficient wetting, impairment of the antioxidant defence system and eye infections. The current work reports on a single step sonochemical coating of CL with ZnO nanoparticles (NPs), chitosan (CS) and gallic acid (GA). GA and CS are expected to improve the comfort of CL by imparting respectively antioxidant properties and enhanced wettability, while their combination with ZnO NPs provides the CL with antimicrobial properties...

HYPOTHESIS: The electrostatic initiation of a jet from the meniscus of a polymeric solution is a key step in near-field electrospinning (NFES), however this process is not sufficiently understood to determine a criterion for the critical emitter voltage triggering the jet, nor to optimize the electrodes. It is expected that the jet initiation in NFES is similar to that in cone-jet electrosprays, and can be described with a first principles model. EXPERIMENTS: The electrostatic jet initiation of an SU-8 polymeric solution is studied with two different electrode geometries to quantify the initiation parameters and illustrate the optimization of the electric field...

While zirconium (Zr)-based metal organic frameworks (MOFs) are promising for conversion of levulinic acid (LA) to γ-valerolactone (GVL) through catalytic transform hydrogenation (CTH), these reported Zr MOFs for LA conversion must be synthesized in toxic dimethylformamide (DMF). From the viewpoint of sustainability, it is preferable to avoid usage of DMF-based solvents to prepare these Zr MOFs. As water is a green solvent, the aim of this study is to develop and investigate Zr MOFs, which are prepared in water, for LA conversion to GVL...

A novel composite of zeolitic imidazolate framework grown on graphene oxide (ZIF-8@GO) was successfully prepared and used for the adsorption of Pb(II) and 1-naphthylamine from aqueous solutions. The effects of contact time, pH, ionic strength and temperature on the adsorption performance of ZIF-8@GO was investigated by batch experiments. Compared to the bare ZIF-8 and GO, the ZIF-8@GO exhibited a significant increase in the adsorption for Pb(II) and 1-naphthylamine. The maximum adsorption capacities of ZIF-8@GO towards Pb(II) and 1-naphthylamine reached 356...

Owing to their unique electronic properties and capability to host diverse functional groups on the surface, carbon dots (CDs) have attracted increasing attention in energy storage field. Herein, ultrathin nitrogen-doped carbon dots (NCDs) decorated nickel hydroxide (Ni(OH)2 ) nanosheets were fabricated by a facile hydrothermal approach, where NCDs play an important role as a structure-directing agent in tuning the size and thickness of the Ni(OH)2 . With the merits of the battery-type faradaic behavior of Ni(OH)2 and high electronic properties of NCDs, the achieved Ni(OH)2 /NCDs ultrathin nanosheets show a specific capacitance of about 1711...

In this study, magnetic graphene oxide modified zeolite (Cu-Z-GO-M) composites with two different ratios of GO to zeolite (named Cu-Z-GO-M 1:2 and Cu-Z-GO-M 1:1) were synthesized by solid-state dispersion (SSD) method. The properties of zeolite-based composites were characterized by SEM, XRD, FTIR, XPS, and magnetization curves. In order to understand the pollutant removal performance of the as-prepared composites, methylene blue (MB) was used as the target pollutant in adsorption experiments. The removal efficiency of MB onto Cu-Z-GO-M composite was enhanced obviously with pH > 9...

Hematite (α-Fe2 O3 ) is the most promising photoanode with a high theoretical photocurrent of 12.6 mA cm-2 . However, the photocurrent of Fe2 O3 achieved now is far below its theoretical value, which is mainly due to its poor electronic conductivity and sluggish water oxidation kinetics. Herein, a co-doping method by sequential in-situ Ti-doping and ex-situ Mg-doping is used to tailor the surface states of Fe2 O3 photoanode for great improvement of the charge transfer at the interface and the followed transport ability by the suppressed charge recombination, resulting in about 11-folds and 6...

Large-sized graphene oxide (LGO) is desirable for many graphene-based applications. Herein, for the first time, we synthesized LGO (83 µm average size) using electrochemically modified graphite as the precursor. With this strategy, we could reduce both the oxidation time (1 h) and oxidant dosage (2 equiv.) while achieving a fast and high-yield (∼90.3 wt%) LGO preparation. LGO papers show much better mechanical properties and nearly four times higher conductivity (after reduction) than their counterparts assembled using small-sized GO...

HYPOTHESIS: Although several researches have explored the dynamics of pluronic aqueous solutions under different conditions, little is known about the dynamical properties of pluronic copolymers in presence of nanoparticles. Knowing and understanding the fundamental dynamical behavior of such systems is crucial to optimize the formulation of high performance multifunctional structures. EXPERIMENTS: In the present work, dynamic light scattering (DLS) is used to investigate the temperature dependence of the dynamical properties of Pluronic F127 aqueous solutions in presence of intercalated chitosan/clay nanocomposites; for comparison, the pluronic aqueous solution and the binary systems pluronic/chitosan and pluronic/montmorillonite having the same copolymer concentration were also investigated...

Interfaces play an important and often limiting role in the mechanical, thermal, and electrical performance of composite materials. Here we suggest a novel method to improve the interfacial interaction in polypropylene-alumina composites using single-walled carbon nanotubes (SWNTs) to nucleate lamellar crystals at the interface. Macroscopic alumina substrates are used to determine the ideal crystallization parameters and investigate the kinetics of crystal growth. SWNTs are uniformly adsorbed to the interface via Van der Waals interactions and lamellar crystals are grown on the surface using isothermal solution processing techniques...

Graphene oxide (GO) has gained popularity in scientific research and industry due to its superior properties, which can be controlled by the synthesis method and graphite feedstock. Despite the availability of different graphite sources, most of the reported studies used natural graphite flake (NGF) as a source of oxidation for GO synthesis. The effect of various alternative graphite feedstocks on the GO properties has not been investigated systematically. This study investigated the influence of graphite feedstock (natural and synthetic) on the characteristics and properties of GO via modified Hummer's method...

Nitrogen-doped layered porous carbon has been successfully fabricated from the biomass of porcine bladders via carbonization and KOH activation. The effects of KOH dosage on the structure, composition and capacitive property of carbon were investigated by a variety of means (SEM, HRTEM, XRD, Raman, XPS, BET and electrochemical test). Owing to the unique layered structure and rich heteroatom content of porcine bladders, the sample obtained at a KOH/carbon mass ratio of 2 were endowed with appropriate pore structure, large specific surface area (1881...

Microfluidic reactors represent a new frontier in the rational design and controllable synthesis of functional micro-/nanomaterials. Herein, we develop a continuous and ultrafast flow synthesis method to obtain triangular silver (tAg) nanoplatelet using a short range two-loop spiral-shaped laminar flow microfluidic reactor, with one inlet flow containing AgNO3 , trisodium citrate, and H2 O2 and the other NaBH4 . The effect of the reactant concentration and flow rate on the structural changes of tAg is examined...

HYPOTHESIS: Recently, molybdenum disulfide (MoS2 ) as a new type of catalyst, has been used for hydrogen evolution. In order to overcome the shortcomings of MoS2 , such as poor conductivity and lack of catalytic activity sites, various materials were added to prepare composites, such as graphene with good conductivity. EXPERIMENTS: In this work, we combined MoS2 with graphene through a very simple liquid-phase salt-assisted co-exfoliation method. The obtained MoS2 /graphene nano-composites have been further applied to electrocatalyst of hydrogen evolution reaction...

When subjected to a sustained load, jammed colloidal gels can feature some delayed viscoplastic creep deformations. However, due to the long timescale of creep (up to several years), its modeling and, thereby, prediction has remained challenging. Here, based on mesoscale simulations of calcium-silicate-hydrate gels (CSH, the binding phase of concrete), we present an accelerated simulation method-based on stress perturbations and overaging-to model creep deformations in CSH. Our simulations yield a very good agreement with nanoindentation creep tests, which suggests that concrete creep occurs through the reorganization of CSH grains at the mesoscale...

Wire-shaped micro-supercapacitors attracted extensive attentions in next-generation portable and wearable electronics, due to advantages of miniature size, lightweight and flexibility. Herein, NiMoO4 nanorods supported on Ni film coated Cu wire are successfully fabricated thorough direct deposition of Ni film onto Cu wire as the conductive substrate, followed by growth of the NiMoO4 nanorods on Ni film coated Cu wire substrate by means a hydrothermal annealing process. The prepared 3D, porous electrode demonstrates extremely high areal specific capacitance of 12...

We report a one-pot seedless green method for the synthesis of gold-silver (AuAg) spiky branched nanostars, with gold (90%) being the major component. Here, the zwitterionic surfactant lauryl sulfobetaine (LSB) is employed in the synthesis of bimetallic nanostars. The concentration of LSB plays an important role in determining the shape of nano-objects. A minimum LSB concentration of 50 mM is required for the formation of spiky branched nanostars, the size of which is controlled by increasing the LSB concentration...

Interface modified SnO2 -TiO2 composite nanoparticles were produced in two stages: first SnO2 nanoparticles were prepared by chemical precipitation in the presence of polyvinylpyrrolidone (PVP) and thermally treated at 500 °C then TiO2 was deposited on top of modified SnO2 and followed by a final annealing. As a consequence SnO2 -TiO2 composite nanoparticles get crystallized while PVP is decomposed into monomer units and other attached smaller molecular fragments. TGA coupled with FT-IR spectroscopy confirmed the presence of monomers and other moieties as a result of PVP thermal fragmentation...