Stress Corrosion Cracking of Pressure Vessel Steel and Countermeasures by Titanium-Based & Cerium-Based Inhibitors in Subcritical Aqueous Environment

An overview of a severe kind of environmentally-assisted cracking-stress corrosion cracking (SCC) of pressure vessel steel (PVS),such as stainless steel 304, alloy 600,690 and other nickel-based alloys in subcritical (～300 ℃) aqueous environment was given. The mechanisms of SCC of metals under this inclement surrounding were briefly generalized. Herein,some pragmatic solutions to mitigate the SCC susceptibility and retard its propagation were presented. The titanium and cerium-based inhibitors addition countermeasure was highlighted.

Effects of Linear Alkylbenzene Sulfonate on Aggregation Behaviors of Titanium Dioxide Nanoparticles in Aqueous Environment

In aqueous environment,organic matters may exert impacts on the aggregation behaviors of titanium dioxide nanoparticles( TiO2-NPs). Owing to the deficiency of studies on the aggregation of TiO2-NPs in the presence of synthetic organic compound,this study used linear alkylbenzene sulfonate( LAS) as a representative to evaluate the effects of TiO2-NPs concentration( 1-10 mg / L),LAS concentration( 0- 1 mg / L),pH( 4- 8)and ionic strength( NaCl,CaCl2; 5- 20 mM) during aggregation of TiO2-NPs suspensions based on the detection of hydrodynamic diameters and electrophoretic mobilities and the calculation of interaction energies.The results showed that the TiO2-NPs in the presence of LAS are more stable than that in the absence of LAS.With the increase of ionic strength,the hydrodynamic diameter of NPs decreases,and the existence of LAS changes the point of zero charge from 5. 4 to a lower value and thus alteres the aggregation behaviors of TiO2-NPs. The present study suggests that the LAS has a significant impact to the transportation and transformation of nanoparticles in aqueous environment.

Experimental observation of Fano-like resonance in a whispering-gallery-mode microresonator in aqueous environment

We report on the transmission spectra of a sausage-like microresonator(SLM)in aqueous environment,where a fiber taper is used as a light coupler.The transmission spectra show an interesting dependence on the coupling position between the SLM and the fiber taper.When the SLM is moved along the fiber taper,the line shape can evolve periodically among symmetric dips,asymmetric Fano-like resonance line shapes,and symmetric peaks.A coupled-mode theory with feedback is developed to explain the observation.The observation of Fano-like resonance in aqueous environment holds great potential in biochemical sensing.

Antenna Enhanced Infrared Photoinduced Force Imaging in Aqueous Environment with Super-Resolution and Hypersensitivity

Tip-enhanced infrared(IR)spectra and imaging have been widely used in cutting-edge studies for the in-depth understanding of the composition,structure,and function of interfaces at the nanoscale.However,molecular monolayer sensitivity has only been demonstrated at solid/gas interfaces.In an aqueous environment,reduced sensitivity limits the practical applications of tip-enhanced IR nanospectroscopy.Here,we present an approach to hypersensitive nanoscale IR spectra and imaging in an aqueous environment with a combination of photoinduced force(PiF)microscopy and resonant antennas.

Determination of gold nanoparticles in natural water using single particle-ICP-MS

A reliable method for detecting nanoparticles is necessary for the wide application of nanomaterials. Single particle-inductively coupled plasma mass spectrometry(SP-ICP-MS) was investigated to detect the size of gold nanoparticles(Au NPs) in this work. Discrimination of particle signal and iterative algorithm were used to calculate the baseline of particle signal. Influence of dwell time was discussed and 3 ms was selected as dwell time for size detection. Different Au NPs standards(30, 60, 80 and 100 nm) and mixed samples(60 and 100 nm) were determined by SP-ICP-MS and the accuracy was confirmed with reference values. The particle size detection limit was 19 nm in ultrapure water(UP water) and 31 nm in 0.1 μg/L Au^(3+) solution. Stability of Au NPs in ultrapure water and natural water samples was investigated by detecting size variation of AuN Ps. The result shows that Au NPs are stable in aqueous environment for 6 d but degraded after 30 d.

Polymeric ultralong organic phosphorescence with excellent humidity and temperature resistance via hydrophobic effect

Polymeric ultralong organic phosphorescence(UOP)with persistent emission is of great importance in practical applications.However,achieving good water-resistance for long-term environmental stability is a formidable challenge.In this contribution,through tailoring the alkyl-chain length of the hardeners and emitters,polymeric UOPs with varying crosslinking density and hydrophobic effect were obtained.Notably,all the polymers show no obvious decrease in UOP emission after high temperature-humidity test(85◦C/85%relative humidity for 7 days).Detailed investigations demonstrate that the rigid covalent crosslinking networks suppress the quenching of triplet excitons while the hydrophobic microenvironment affords good water/moisture-resistance ability.Moreover,the polymers with superior processability are successfully applied as optical coatings,prepreg,and afterglow displays.With this work,we provide a new strategy to promote the long-term stability of polymeric UOP materials in high-temperature-humidity conditions.

Sensitization of europium(Ⅲ) luminescence in water with β-diketone-poly(ethylene glycol) macroligand

Poly（ethylene glycol）-modified 13-diketone macroligand is developed to sensitize europium（III） ions in water. High lumines cence intensity characteristic of Eu3 was achieved due to spontaneous formation of micelle-like structure in which the hydro phobic core prevents luminescence-quenching by water molecules. The pH is found to induce a quantitative ratio change in two fluorescence bands from both ligand and Eu3.

H_6P_2W_(18)O_(62)á18H_2O: A green and reusable catalyst for one-pot synthesis of pyrano[4,3-b]pyrans in water

A convenient,effcient and environmentally benign procedure has been developed for the synthesis of pyrano[4,3-b]pyran derivatives via a one-pot,three-component reaction of 4-hydroxy-6-methylpyran-2-one,aldehydes and malononitrile in water using H6P2W18O62á18H2O as catalyst.Reusability of the catalyst and reaction media,short reaction times and easy isolation of products are some added advantages of the present methodology.