Determination of nanoparticles concentration in solution based on Pickering emulsion destabilization analyses

The dynamic development of nanotechnology research has contributed to the fact that various types of nanoparticles are increasingly used on a large scale both for medical and biological purposes, but above all in many industrial fields. Such a wide application of nanoparticles is often connected with the need to estimate their characteristic parameters, such as size, size distribution or concentration. Existing instruments are usually quite expensive and not always available. Therefore, other cheaper and simpler methods based on analytical techniques are sought. In this paper, we have proposed a method to estimate the concentration of nanoparticles in solutions based on destabilization analyses of Pickering emulsions produced with their use. The fact of mutual relationship between emulsion concentration, nanoparticle concentration and emulsion stability was used here. The study was carried out using silica nanoparticles. It was presented how to apply the method and what are its limitations. Moreover, an example of its application for the determination of nanoparticle concentration in an unknown sample, obtained after analysis of the permeability of membranes in diffusion chambers, has been presented. The method can become a useful alternative for the determination of nanoparticle concentration in solution in places where no specialized equipment is available.

Tribological Properties of ZrO2 Coating on the Ball Joint of an Axial Piston Pump in High Water-Based Emulsion Medium

This paper studies the tribological properties of the ZrO2-coated spherical joint pair of the axial piston pump in a high water-based emulsion medium. Firstly, atmospheric plasma spraying was used to prepare the ZrO2 coating on the surface of the spherical joint pair. Secondly, the tribological characteristics of the steel-steel pair and ceramic-ceramic pair were analyzed by the friction and wear testing machine under the conditions of a high water-based emulsion concentration, load size, and load frequency. White light interference three-dimensional surface profiler and scanning electron microscope were used to analyze the original and worn surfaces of the samples, and then the friction and wear of the different material pairs were discussed. The results show that the friction reduction and wear resistance of the ceramic ball joint are superior to those of the steel ball joint. When the load is 100 N, the frequency is 1 Hz, and the emulsion concentration is 5%, and the friction coefficient and wear loss of the ceramic-ceramic ball joint pair are the lowest. The emulsion concentration and load have great influence on the friction coefficient and wear amount, while the frequency has little influence on them. With increasing concentration of the emulsion, the friction coefficient decreases and tends to be stable, but with increasing of load, the friction coefficient and wear increase. The friction coefficient and wear loss of the ceramic-ceramic ball joint in pure water are 0.25 times higher than those of the steel ball joint under the same working conditions. Therefore, when the concentration of the high water-based emulsion is 5%, 100 N load, 1 Hz frequency, the ceramic-ceramic ball joints display the best friction and wear resistance of the two. The research results provide a theoretical basis for the design, manufacture, and application of the ceramic coating hydraulic components in a high water-based emulsion medium.

Improved Hydrophobicity and Dimensional Stability of Wood Treated with Paraffin/Acrylate Compound Emulsion through Response Surface Methodology Optimization

Wood treatment was conducted by paraffin/acrylate compound emulsion. Response surface methodology (RSM) was applied for modeling and to determine the relationship between hydrophobicity and influencing factors. The results showed that the paraffin emulsion concentration and acrylate emulsion percentage had significant influences on water absorption (WA) and mass percentage gain (MG). The WA decreased obviously with increasing acrylate emulsion percentage. The correlation models for WA and MG showed a good prediction due to the straight-line distribution in the normal probability plot of residuals. The optimal conditions (5.57% paraffin emulsion concentration, 20% acrylate emulsion percentage, and 10 min treatment time) provided by RSM were acceptable for predicting the MG and WA. Compared to untreated (66°) and paraffin emulsion treated wood (94°), the wood treated by compound emulsion showed the highest water contact angle (133°) and better dimensional stability. This could be ascribed to a synergistic effect (bulking effect and filling effect) provided by paraffin and acrylate, which could form a completely hydrophobic film in wood.

Synchronous fluorescence spectra of water contaminated by dispersed crude oil

The development of petroleum extraction and transport technology does not ensure complete isolation of these substances from the natural environment. This problem is exacerbated by the location of mining equipment on the sea shelf and the fact that numerous submarine pipelines, tankers and handling terminals can also emit oil pollution. Therefore, the possibility of detecting oil dispersed in the water is particularly important. This paper reports the efforts to identify methods of characterization of the water containing the crude oil emulsion in a very low concentration (a few to several tens of ppm). Due to this, the effect of emulsion concentration on the possibility of its objective characterization using synchronous fluorescence spectra was studied. The similarity of spectra at various oil concentrations was analysed. It has been shown that the stabilization of the shape of synchronous fluorescence spectra occurs at relatively low oil concentrations.

Synthesis of Novel Cationic Waterborne Polyurethane from Natural Rubber and its Properties Testing

The novel natural rubber based cationic waterborne polyurethanes (cWPUs) with having quaternary amine as an emulsifier were successfully synthesized by additional polymerization. These polyurethanes were synthesized by the reaction of hydroxyl the method of telechelic natural rubber. Molecular weight approximately of hydroxyl telechelic natural rubber (HTNR) for 3000 g.mole-1, toluene-2,4-diisocyanate (TDI), and N-methyl diethanol amine (NMDEA) (used as an emulsifier) were prepared for cWPU. The concentrations of NMDEA were examined in range of 0 – 2.0 moles. From the results under the isocyanate index of 100, the study revealed that cWPU with well-distributing had to consist of emulsion concentration more than 1.50 moles. Zetasizer nanorange was used to identify the prepared cWPU particle size distribution. The results showed that the particle size of cWPU was decreased from 86.6 to 78 nm with increasing of NMDEA concentration. The smallest particle size was 2 moles with non-acetic acid odor, and very soft film. In addition, cWPU would be well-dispersed more than 4 months. The 1H NMR spectroscopy and FT-IR confirmed that the cWPU has been successfully synthesized from natural rubber.

Study on waxing of cut foliage post harvest life of few ornamental species

Enhancing the vase life of cut foliages is one of the prime goals of floriculturist and it is very interesting and important aspect of floriculture.The efforts were made to find out best waxing treatment for enhancing the vase life along with excellent quality maintenance for few cut foliage species .The objective was to evaluate optimum percent wax solution for improving post harvest life and quality of ornamental plants. Different wax emulsion treatments (0.25, 0.50, 0.75 and 1.00 %) showed significant results in both quantitative and qualitative attributes of ornamental species. In Asparagus densiflorus ‘Sprengeri’ and Eucalyptus teritecornis,0.75% wax emulsion concentration recorded minimum foliage weight (5.62, 20.49 g) and minimum water uptake (5.60, 32.73 ml) respectively on 3rd day, while maximum foliage weight (0.90, 6.84 g) and maximum water uptake (1.13, 13.77 ml) was recorded on senescence day. In Caryota urens (Fishtail palm) 0.50% wax emulsion concentration recorded minimum foliage weight (9.71 g), minimum water uptake (6.53 ml) on 3rdday, while maximum foliage weight(1.83 g) and maximum water uptake (1.20 ml) on senescence day. In Heliconia psittachroum cv. Golden Torch, 1.00 % wax emulsion concentration recorded minimum foliage weight (28.85 g), minimum water uptake (20.35 ml) on 3rdday, whereas maximum foliage weight (15.83 g)and maximum water uptake (5.75 ml) on senescence day. There was improvement and increament in post harvest quality and vase life of studied ornamental cut foliages.

Emulsion Breaking of Used Cutting Fluid by Electrocoagulation Method to Decrease Water Pollution

Cutting fluids are liquids having different compositions that are used in metal possessing operations. After being used, the fluids became less effective and need to be changed. In this research the treatment of petroleum oil emulsion type cutting fluid has been carried out using electrocoagulation technology to decrease its environmental impact on water resources. Cutting oil type 7201 produced in (Al-daura) refinery has been treated at different concentrations (1, 2, 3 and 4%) by weight to study the effect of the cutting fluid concentration on the time needed for emulsion breaking. The effect of other parameters such as electrical voltage (by using 40, 50 and 60 volt), aluminum metal electrodes' surface area (by using 4 and 6 cm²) and the effect of added NaCl salt concentrations (by using 0.2, 0.27 and 0.33% by weight) on the emulsion breaking time has been studied. It has been found that there is an optimum voltage for each emulsion concentration and the emulsion breaking time increase with the increase of the cutting fluid concentration and it decrease with the increase of the electrode surface area and the salt concentration.