High Surface Free Energy Research Articles

Modified Nanopolystyrene as a Plugging Agent for Oil-Based Drilling Fluids Applied in Shale Formation

Most nanoplugging agents have high surface free energy and tend to aggregate in oil-based drilling fluids (OBMs), failing to plug the nanopores in the formation. This paper introduces the synthesis and application of a surface-modified nanoscale polystyrene (NS) as a plugging agent for OBMs. With oleic acid acting as the surface modifier, the surface free energy of the NS can be effectively reduced, which is a crucial step in enhancing its dispersion stability in mineral oil. Besides, due to the nanoscale size and low surface free energy, NS adsorbing onto the rock surface could improve the contact angle of the mineral oil on the rock surface, reduce the imbibition amount of oil into the rock, and maintain the mechanical stability of the rock. The structure of NS was characterized by infrared spectroscopy and transmission electron microscopy. Thermal gravimetric analysis demonstrated that NS could resist up to 252 °C. The particle size distribution test showed that NS could maintain the nanoscale dispersion in mineral oil. NS could also increase the contact angle of mineral oil on the rock surface from 12 to 61° and reduce the oil spontaneous imbibition amount by 52.7%. After the addition of 2% NS to the base mud, the permeability plugging apparatus filtration loss was reduced by 67% compared with that of the base mud without NS, and in the pressure transmission test, the downstream pressure was still kept constant with no noticeable change after 60 h, showing an excellent plugging effect. Besides, after the rocks were immersed in the base mud and base mud containing 2% NS, the uniaxial compressive strength of the rock declined by 25.41 and 10.76%, respectively, indicating that NS could effectively alleviate the mechanical stability decrease of the rock.

Ionic Liquid-Mediated Mass Transport Channels for Ultrahigh Rate Lithium-Ion Batteries.

Excellent mass transport capability is indispensable to building a high-power lithium-ion battery (LIB) system. Nanomaterials with enhanced electrochemical properties have been used for next-generation high-performance LIBs. However, due to the high surface free energy, nanomaterials tend to form agglomeration. The resulting insufficient mass transport channels limit the high rate performance of nanomaterials. Here, we increase the electrolyte accessibility of nanomaterials through a facile ionic liquid (IL) mediation method. The fluidity and affinity enable the IL to infiltrate into the interstitials of nanomaterial aggregations under capillary force, enhancing the electrochemically active contact area and ensuring rapid mass transport. As a proof of concept, IL-mediated LiFePO4 electrodes delivered extraordinary rate performance (112 and 95 mAh g-1 at 200 and 300 C, respectively). In terms of simplicity, the IL mediation can be used as a general strategy to achieve an ultrahigh rate for LIBs.

Experimental Investigation of the Wettability of Protective Glove Materials: A Biomimetic Perspective

Abstract The objective of the present work was to evaluate the surface wettability of commercially available polymeric protective gloves, as well as to determine the effects of their surface topography in conjunction with the glove material on the hydrophobic properties of the final products, together with surface free energy (SFE) and work of adhesion. The geometric structures imparted to the surface led to different levels of hydrophobicity and SFE. Most of the studied materials were characterized by good wettability properties. It was shown that a textured surface topography affects wettability. The highest SFE was found for nitrile butadiene rubber materials. All materials except for nitrile butadiene rubber exhibited good hydrophobic properties and relatively low work of adhesion.

Mitigation of fouling during milk processing in polytetrafluoroethylene‐titanium dioxide coated plate heat exchanger

AbstractAn attempt was made to mitigate fouling during milk processing in plate heat exchanger by modifying SS316 surface with the coating of polytetrafluoroethylene (PTFE) and titanium dioxide (TiO2) nanoparticles. The surface characteristics of PTFE‐TiO2 coated and conventional SS316 plates, and their thermal performance during heating of milk in batches for 8 hr were compared. It was observed that the static contact angles of water on SS316 and PTFE‐TiO2 coated plates were 66.8 ± 6.3° and 112.8 ± 0.8°, while for milk they were 61.0 ± 6.1° and 97.5 ± 1.1°, respectively. The increase in contact angle for coated surface was suggestive of weaker interaction between the fluid and surface, and enhancement in hydrophobicity. Overall heat transfer coefficients for uncoated and coated plates ranged from 354.36 to 952.26 Wm−2 K−1 and 477.11 to 593.73 Wm−2 K−1, whereas the fouling factor was 1.723 × 10−3 and 0.412 × 10−3 m2KW−1, respectively. As deposition of foulants occurred, the overall heat transfer coefficient of SS316 and coated surfaces dropped by 62.15 and 19.40%, respectively, from the initial value, resulting in crossover of the curves at 310 min of heating milk. After 480 min of heating milk, the fouling factor of SS316 plates was at least four times higher than that of PTFE‐TiO2 coated plates. The PTFE‐TiO2 coating mitigated the deposition of milk foulants by 20 times than that of SS316 surface.Practical ApplicationsFouling of plate heat exchangers (PHE) during milk processing is an unsolved problem causing significant loss in heat transfer performance, increased pressure drop in flow between plates, loss of process time due to cleaning and impairment of product quality. The high surface free energy and hydrophilic adhesion of SS316 to milk act as stimulants to fouling. Modification of SS316 plates in PHE with coating of polytetrafluroethylene and titanium dioxide nanoparticles mitigates fouling. Coated plates maintain the heat transfer performance of the plates for extended time and reduce the cleaning requirement. Also, savings in harsh chemicals, water, and pumping costs could be realized.

Cationic waterborne polyurethane–chitosan based on natural rubber as new green antimicrobial coating

This is the first report on developing new methodologies to synthesize hydroxytelechelic natural rubber (HTNR), a bio-polyol based on natural rubber (NR), by mechanical and chemical degradation. The mechanical degradation of NR from shear during mastication leads to a lower molecular weight before oxidative cleavage by periodic acid. The effects of the molar ratio of periodic acid/isoprene unit ([H5IO6]/[isoprene unit]) on properties of HTNR were investigated. The end-functionality was determined by 1H NMR spectroscopy and the molecular weight was determined by SEC. The HTNR polyol with 3000 g/mol molecular weight and H5IO6 at 0.07 ratio were used as precursors to synthesize cationic waterborne polyurethane (cWPU). The cWPU had a well-defined size distribution and was stable for at least 3 months. The chemical structure of cWPU was confirmed by 1H NMR spectroscopy. Moreover, the hydrophilic properties and antimicrobial properties of cWPU improved when mixed with 1% solution of protonated chitosan (PCS). In addition, the effects of PCS content were studied. The investigations showed that increasing PCS gave a more hydrophilic surface with a low contact angle and a high surface free energy for the cWPU-PCS film. Furthermore, PCS at over 3%wt content inhibited E. coli growth. Hence, the new cWPU mixed with chitosan could serve as an alternative antimicrobial coating material.

Effect of Plasma Surface Modification on Print Quality of Biodegradable PLA Films

PLA films, as non-absorbent materials, require modification of the surface before the printing process in order to improve the wettability of the substrate and to obtain proper ink adhesion to the substrate. In this paper, the surfaces of two kinds of PLA films were modified using plasma activation with parameters enabling high surface free energy (SFE) values, and then the films were printed on using different kinds of flexographic inks. Two gases, oxygen and argon, were used for activation, as these make it possible to obtain good hydrophilicity and high SFE values while having different effects on the roughness, or the degree of surface etching. Plasma-activated films were subsequently subjected to the measurements of: contact angle with water, diiodomethane and three printing inks, roughness, weight change, strength properties, color and gloss change, and SFE was determined. Unmodified and activated films were flexographically printed in laboratory conditions and then the quality of obtained prints was analyzed. The results showed a strong effect of activation with both oxygen and argon plasma on the SFE value of the films and the contact angles of water and inks, with the gas used for plasma activation and the type of film significantly influencing the thickness of the fused ink layer and the resultant color. Moreover, plasma activation had a especially favorable and significant effect on the quality of prints made with water-based inks, while it had little effect when printing with solvent-based inks.

Fabrication of Mg Coating on PEEK and Antibacterial Evaluation for Bone Application

Polyetheretherketone (PEEK) is an alternative biomedical polymer material to traditional metal and ceramic biomaterials. However, as a bioinert material, its wide application in the medical field is seriously restricted due to its lack of bioactivity. In this research, pure Mg was successfully deposited on a PEEK substrate by vapor deposition to improve the antibacterial properties of PEEK implants. The morphology and elemental composition of the coating were characterized by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The higher the deposition temperature, the larger the Mg particle size. The Mg coating possesses a hydrophilic surface and a higher surface free energy that create its good biocompatibility. The Mg coating on a PEEK substrate withstands up to 56 days’ immersion. The antibacterial test showed that the antibacterial rate of coated PEEK is 99%. Mg-coated PEEK demonstrates promising antibacterial properties.

Impact of Surface Topography, Chemistry and Properties on the Adhesion of Sodium Alginate Coatings Electrophoretically Deposited on Titanium Biomaterials

In this paper, we report on the electrophoretic deposition and characterisation of pure sodium alginate coatings on titanium biomaterials, the commercially pure titanium CP-Ti1 and Ti–13Nb–13Zr titanium alloy. Various solutions differing in the distilled water to ethanol volume ratio and sodium alginate concentration were used for coating deposition. Uniform, dense and continuous coatings with a thickness up to 1 µm were deposited. The effect of surface topography and morphology, wettability and surface free energy as well as surface chemistry on the coating adhesion to the titanium biomaterials were investigated. The coatings exhibited very good adhesion to the polished and then chemically treated alloy. The adhesion mechanisms were identified. The chemical bonding and interfacial adhesion mechanisms are plausible. The coatings exhibited low surface development, dependent on the applied substrate roughness. Sodium alginate coatings on both substrates showed moderate hydrophilicity and relatively high surface free energy, on average 30 pct higher in comparison with that of the substrate materials. The obtained results will be useful for the further development of composite sodium alginate coatings for enhancing the biological performance of titanium biomaterials.

Direct measurement of surface adhesion between thin films of nanocellulose and urea–formaldehyde resin adhesives

When applying an adhesive to wood, the chemical heterogeneity of the wood cell walls makes it difficult to understand the contribution they make to the interfacial adhesion between the adhesive and the wood as the adhesion is a very complex physical and chemical phenomenon. This study, for the first time, directly measured the surface adhesion between cellulose, a major component of wood, and urea–formaldehyde (UF) resin adhesives. The adhesion between thin, smooth nanocellulose films, such as cellulose nanofibrils (CNFs), carboxymethylated nanofibrils (CM)–CNFs, and carboxylated cellulose nanocrystals (C–CNCs), and UF resins with two formaldehyde to urea (F/U) molar ratios of 1.0 and 1.6 was measured using two approaches: (1) direct measurement of the adhesion force between nanocellulose films and liquid droplets of the UF resins, and (2) calculation of the work of adhesion between films of the nanocelluloses and UF resins using the contact angle and the van Oss–Chaudhury–Good method. The results show that the total surface free energies, either between the different nanocelluloses or between the two UF resins are somewhat similar, indicating the similarity in their surface properties. However, the adhesion force and work of adhesion of 1.6 UF resins with different types of nanocellulose are higher than those of 1.0 UF resins, which shows that van der Waals forces are dominant in their molecular interactions. These results suggest that the adhesion between 1.6 UF resins and nanocellulose is stronger than that when 1.0 UF resins are used because the 1.6 UF resins have a more branched structure, smoother surface, and higher surface free energy.

In Situ Confining Pt Clusters in Ultrathin MnO2 Nanosheets for Highly Efficient Hydrogen Evolution Reaction

Rational synthesis of highly dispersed electrocatalyst with excellent electrocatalytic performance is critical for energy and environment applications. However, metal cluster with high surface free energy remains a challenge for the synthesis of stable and highly active catalysts. Herein, a highly dispersed platinum cluster anchored on the Mn vacancy of MnO2 nanosheets (PtAC‐MnO2) via in situ electrochemical methods is reported. The strongly binding energy between Pt clusters and supports can effectively suppress the migration of active Pt atoms and optimize their electronic structure for excellent electrocatalytic properties. Impressively, the PtAC‐MnO2 demonstrates a considerably low overpotential (η100) of 47 mV at 100 mA cm−2 and can be catalyzed continuously at 10 mA cm−2 for 80 h, showing better catalytic stability than the state‐of‐the‐art commercial Pt/C catalysts. A cationic vacancy defect strategy for the design and preparation of metal cluster catalysts is provided.

Saliva and Serum Protein Adsorption on Chemically Modified Silica Surfaces

Biomaterials, once inserted in the oral cavity, become immediately covered by a layer of adsorbed proteins that consists mostly of salivary proteins but also of plasma proteins if the biomaterial is placed close to the gingival margin or if it becomes implanted into tissue and bone. It is often this protein layer, rather than the pristine biomaterial surface, that is subsequently encountered by colonizing bacteria or attaching tissue cells. Thus, to study this important initial protein adsorption from human saliva and serum and how it might be influenced through chemical modification of the biomaterial surface, we have measured the amount of protein adsorbed and analyzed the composition of the adsorbed protein layer using gel electrophoresis and western blotting. Here, we have developed an in vitro model system based on silica surfaces, chemically modified with 7 silane-based self-assembled monolayers that span a broad range of physicochemical properties, from hydrophilic to hydrophobic surfaces (water contact angles from 15° to 115°), low to high surface free energy (12 to 57 mN/m), and negative to positive surface charge (zeta potentials from –120 to +40 mV at physiologic pH). We found that the chemical surface functionalities exerted a substantial effect on the total amounts of proteins adsorbed; however, no linear correlation of the adsorbed amounts with the physicochemical surface parameters was observed. Only the adsorption behavior of a few singular protein components, from which physicochemical data are available, seems to follow physicochemical expectations. Examples are albumin in serum and lysozyme in saliva; in both, adsorption was favored on countercharged surfaces. We conclude from these findings that in complex biofluids such as saliva and serum, adsorption behavior is dominated by the overall protein-binding capacity of the surface rather than by specific physicochemical interactions of single protein entities with the surface.

Properties of CaP coatings produced by reactive RF-magnetron sputtering in a mixture of nitrogen and noble gases

Calcium phosphate coatings are widely used to increase the biocompatibility of metal implants. Nowadays various dopants in the structure of calcium phosphate coatings are actively studied. Nitric oxygen is known as an essential mediator of blood flow. Its presence in the structure of calcium phosphate coating can stimulate angiogenesis and promote osseointegration of the implant. This article is dedicated to the study of morphology and physico-chemical properties of the calcium phosphate coatings formed via reactive RF-$$$magnetron sputtering of hydroxyapatite in the mixture of noble gases (Ne, Ar and Xe) and nitrogen with the same volume concentrations. There is a decrease in grain size and an increase in roughness with the growth of the atomic mass of noble gas in the mixture with nitrogen. The Ca/P ratio also decreases with the increase in the atomic mass of noble gas. Coatings formed in Ne + N2 and Xe + N2 gas mixtures are characterized by higher surface free energy in comparison with the ones formed in Ar + N2. It allows us to suggest that the coatings formed in Ne + N2 and Xe + N2 are more biocompatible than ones formed in Ar + N2, however, additional studies are needed to prove it.

Revealing Active Sites in Atomically Dispersed Metal Catalysts on N-Doped Carbon for Electrocatalytic CO2 Reduction By Operando XAS

Single-atom catalysts (SACs) represent a promising class of low-cost materials with high catalytic activity and 100% atom-utilization efficiency, widely applied in energy conversion fields.[1-2] Benefit from tunable coordination environment, the uniformly dispersed SACs on diverse supports exhibit satisfied catalytic ability. More importantly, different from the multiple crystal facets of nanomaterials can serve as active sites. There is only one active site consisting of the single metal atom and coordinated atoms in SACs, thereby improving the selectivity of products some catalytic reactions. Moreover, atomically dispersed metal catalysts exist in cations, which exhibit better stability than traditional nanoparticulated counterparts.[3] However, SACs are susceptible to undergo restructuring during the reactions because of high surface free energy. Therefore, exploring the active sites of SACs through in-situ characterization techniques plays a critical role in studying the reaction mechanism and guiding the design of optimum SACs.As a synchrotron-based element-specific technique, X-ray absorption spectroscopy (XAS) is influential in studying the probed element's structural information. X-ray absorption near edge structure (XANES) spectra reflect the electronic structure, while extended X-ray absorption fine structure (EXAFS) spectra provide local atomic structural information such as coordination number, bond length, and structural disorder. Thus, in-situ XAS is promising and widely used for monitoring electronic structure and atomic configuration changes of SACs during real-time working conditions. We have prepared Ni, Cu single atoms on nitrogen-doped carbon (NiCu@NC-900), which exhibit improved catalytic ability compared with Ni SACs and Cu SACs. Nuclear magnetic resonance results show only ethanol as a liquid product during CO2 reduction reaction (CO2RR). To explore the origin of improved catalytic performance of SACs toward CO2RR, we are going to monitor changes of SACs under open-circuit voltage (OCV) and working conditions by Operando XAS.[1] Li, Z., Ji, S., Liu, Y., Cao, X., Tian, S., Chen, Y., Niu, Z., Li, Y. Chem. Rev. 120, 2 (2020).[2] Ji, S., Chen, Y., Wang, X., Zhang, Z., Wang, D., Li, Y. Chem. Rev. 120, 21 (2020).[3] Speck, F. D., Paul, M. T. Y., Ruiz-Zepeda, F., Gatalo, M., Kim, H., Kwon, H. C., Mayrhofer, K. J. J., Choi, M., Choi, C. H., Hodnik, N., Cherevko, S. J. Am. Chem. Soc. 142, 36 (2020).

Water-soluble electrospun strip based on the PVP/PVA/ mint extract modified with chitosan-glucosamine for the improvement of water quality

Water-soluble nanocomposite strip samples were prepared based on the polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), and chitosan or chitosan-glucosamine (C-G) via electrospinning process. Degree of deacetylation (DD), water solubility, and x-ray diffraction (XRD) analyses confirmed that C-G with DD of 52.11% had the best solubility in water at room temperature. Electrospun strip samples that contained C-G as an additive in their structure (S4-S6) had shown excellent water solubility. XRD and differential scanning calorimetry (DSC) results in accordance with water-solubility study of strip samples confirmed that S4-S6 had a low crystalline portion rather than others. Thermo-gravimetric analysis (TGA) verified the validity of chitosan modification. Water contact angle (WCA) verified that the strip sample with 8wt% PVP-K90 had the lowest contact angle and the highest surface free energy. Scanning electron micrographs (SEM) revealed a uniform and bead-less structure of obtained nanofibers. Also, In-vitro cytotoxicity assay confirmed that strip samples had more than 85% cell viability which demonstrated the biocompatibility of them. Based on the achieved results, S5 was the best sample and selected for antioxidant activity analysis. Hydroxyl scavenging, superoxide anion scavenging, and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging were performed for evaluating antioxidant properties of samples and the results exhibited that S5-3 and S5-4 samples which contained the highest amount of mint extract had the highest antioxidant properties.

Structural design of metal catalysts based on ZIFs: From nanoscale to atomic level

AbstractUltrasmall metal nanoparticles (MNPs) and atomically dispersed metal sites (ADMSs) exhibit excellent catalytic activity and selectivity. However, they tend to aggregate into large particles during synthesis and catalysis due to high surface free energy. Aiming to break out of this dilemma, zeolite imidazolate frameworks (ZIFs) have proved to be ideal substrates for stabilizing the ultrafine metal nanostructures. The stabilizing mode includes confining MNPs inside their pore structures and converting intrinsic metal nodes into coordinately unsaturated metal sites (i.e., ZIF‐confined metal catalysts). Furthermore, various MNPs and ADMSs can also be immobilized into ZIF‐derived porous carbon through high‐temperature pyrolysis (i.e., ZIF‐derived carbon‐supported metal catalysts). In brief, ZIFs and their derivatives have gradually emerged as good platforms for designing metal catalysts at nanoscale and even atomic level. In this review, recent progress in the structural analysis and synthetic strategies of metal catalysts supported by ZIFs and their derivatives is presented. Besides, current challenges and future directions of atomically dispersed metal catalysts are discussed. This article will provide valuable insights into rational design of metal catalysts with exquisite nanostructure and high catalytic performance to meet further material requirements in the catalytic field.

Development of membrane distillation by dosing SiO2-PNIPAM with thermal cleaning properties via surface energy actuation

This study evaluates the performance and cleaning efficiency of Direct Contact Membrane Distillation (DCMD) by changing its surface energy via thermal actuation. Thermoresponsive SiO2-PNIPAM particles were dosed into the DCMD with different surface energy and its thermal cleaning efficiency was evaluated against the model organic foulants namely Bovine Serum Albumin (BSA) and Sodium Alginate (SA). The impact of SiO2-PNIPAM dosing on the performance of membrane distillation as well as its defouling efficiency were evaluated under thermal actuation effect. Results showed that composite membrane has higher flux recovery (93%–95%) compared to pristine membrane (55%–90%). The composite membranes were analysed for their Surface Free Energy (SFE) to understand their fouling and cleaning behaviour. Based on SFE analysis, it was found that both low and high SFE composite membranes surface that fouled by BSA and SA foulants were able to restore their hydrophobicity after thermal actuation. The stability of the embedded hydrogel could be maintained after thermal actuation which indicated sufficient interactions between the SiO2-PNIPAM with the PVDF membrane matrix.

Modification of PLA Scaffold Surface for Medical Applications

Materials used for medical applications (e.g., the cellular scaffold) should have not only the specific chemical composition, but the surface layer properties as well. For this reason, a method which enables an increase in the number of pores, wettability of the surface, and improvement the conditions of nutrient transportation into the membrane is being studied. The plasma of a dielectric barrier discharge was applied for the surface modification of polylactide obtained by dry or wet phase inversion. The plasma-modified surface was analyzed by contact angle measurements with water and diiodomethane. The surface free energy (SFE) was calculated by the Owens–Wendt method. The highest SFE and its polar component (67.6 mJ/m2 and 39.5 mJ/m2, respectively) were received when the process was conducted in an Ar + CO2 gas mixture with a discharge power of 20 W. The purpose of this research was to increase the wettability and porosity of the membrane’s surface. It can be concluded that the dielectric barrier discharge can effectively change the surface of the polylactide membranes, and that the structure of the modified membranes was not damaged during modification. The process of modification was easier for the membranes made by dry phase inversion. These materials had higher SFE values after the modification.

Structure induced wide range wettability: Controlled surface of micro-nano/nano structured copper films for enhanced interface

The wettability of materials used in the production of devices employed in various technological domains have attracted significant attentions. Therefore, it is important to design the surfaces of these materials such that they can provide the required surface free energy and simplify the interfacial structure. Herein, various Cu films with a highly controllable surface wettability and a wide range of contact angles ranging from 6° to 152° were fabricated, and the corresponding mechanism was discussed. A wide range of wettability was realized by controlling the surface structure of the Cu film. The nanogap structure of the vertical nanowire-array film led to a high surface free energy. Similarly, the oblique nanowire-array film increased the surface free energy; however, the surface free energy was dependent on the size of the nanowires rather than on the nanogaps owing to the crystallinity of the film. Additionally, cluster-nanowire-array films were designed to realize a wettability transition from hydrophilicity to hydrophobicity with a constant surface free energy. The Cu foam possessed a superhydrophilic surface owing to its high porosity, whereas the cluster-nanoparticle structure possessed a superhydrophobic surface. In addition, we noted that the structure-induced wettability played an important role in tuning the semiconductor and metal interfacial stress and simplifying the interfacial structure. Furthermore, the outstanding electrical conductivity of the Cu films indicates its promising potential as an electrode. The structure-induced wettability proposed in this study can be applied for a wide range of materials, particularly for films used for advanced applications.

Interactions between peracetic acid and TiO2 nanoparticle in wastewater disinfection: Mechanisms and implications

While peracetic acid (PAA) are known to be susceptible to decomposition by metals for radical generation, herein we report a novel decomposition process of PAA with TiO2 nanoparticle (nTiO2) for the first time. nTiO2 in anatase (A_nTiO2) could significantly enhance the decomposition of PAA, whereas, nTiO2 in rutile phase had no impact on the stability of PAA. Electron paramagnetic resonance (EPR) technique and a radical quenching study indicated lack of involvement of reactive radicals. In-depth investigation revealed that the {001} facets of A_nTiO2 with high surface free energy were especially reactive for the catalytic decomposition of PAA. Theoretical calculations proved the adsorption of PAA onto A_nTiO2 {001} surface was much more favorable than the predominated {101} facets. The unsaturated five coordinated Ti (Ti5c), typical Lewis acid sites on A_nTiO2 {001} surface, were further confirmed as the dominant active sites for catalyzing PAA decomposition. This novel decomposition process could enhance the stability and migration of A_nTiO2, increasing the potential environmental risk. Meanwhile, the disinfection of PAA was inhibited by introducing A_nTiO2. The new findings of this study broaden the knowledge on PAA decomposition process, and have an important implication for PAA disinfection and environmental behavior of TiO2 nanoparticle.

The stabilization of supported Au nanoparticles in a highly sintering environment using high surface free energy Pt and Ru cores

To stabilize carbon supported gold nanoparticles which sinter rapidly in a corrosive environment, bimetallic Ru@Au and Pt@Au core–shell supported nanoparticles were prepared by anchoring shells of Au onto higher surface free energy cores of Pt and Ru.