Fabrication, Tensile Properties, and Photodecomposition of Basalt Fiber-Reinforced Cellulose Acetate Matrix Composites

Cellulose acetate (CA) is widely used as an alternative to conventional plastics because of the minor environmental impact of its decomposition cycle. This study synthesized five-layer environmentally friendly composites from CA bioplastic and basalt fibers (BFs) to produce a high-strength marine-biodegradable polymer. Maleic anhydride-grafted polypropylene (PP-g-MAH) was mixed with CA as a surface-active agent (SAA) to understand the effect of surface treatment on the mechanical properties of the composite. Tensile tests and scanning electron microscopy were conducted to observe the fracture surfaces. The ultimate tensile strength (UTS) of the BF/CA composite increased by approximately a factor of 4 after adding 11 vol.% unidirectional BF. When the SAA was added, the UTS of the composite with 11 vol.% BF was multiplied by a factor of about 7, which indicates that the surface treatment has a significant positive effect on the mechanical properties. However, the improvement is not apparent when the added BFs are in a plain weave with a vertical orientation. A photodecomposition experiment was then conducted by adding TiO2. Observing the UTS changes of the CA and BF/CA composites, the effect of the photocatalyst on the decomposition of the materials was explored.

Development of Nifedipine Amorphous Solid Dispersion Composed of Surface-Active Agents

The amorphous solid dispersions (ASDs) containing amino methacrylate copolymer and surface-active agents were prepared to improve the nifedipine (NDP) dissolution. The different types of surface-active agent i.e., polysorbates 80, sodium lauryl sulfate (SLS) and polyethylene glycol (PEG) 400 were used. In order to evaluate the ASDs formulation,powder X-ray diffractometry and thermal analysis to characterize NDP crystallinity in ASDs and the dissolution study of NDP have been performed to compare the dissolution profiles. The ASDs were kept for 6 months to investigate the stability. In the X-ray diffraction pattern, no peak was observed in all samples of ASDs. No peak was found in sample of all ASDs from the thermograms. These results suggest that the drug may be molecularly dispersed in matrix of amino methacrylate copolymer. The drug dissolution at 120 min, from ASDs without surface-active agent and NDP powder were 58.31% and 17.95%, respectively. The dissolved NDP from ASDs composed of SLS, polysorbate 80 and PEG400 were 96.25%, 88.86% and 75.32%, respectively. These results may occur due to the reduction of surface tension, the addition of the low amount of high efficiency of surface-active agent e.g., SLS (compared with PEG400 and polysorbate 80) provided the higher NDP dissolution. The content analysis of NDP in selected ASDs was studied at the end of 3 and 6 months, the NDP content remained unchanged after storage.

PREPARATION OF GEOTHERMAL SILICA GLASS COATING FILM THROUGH MULTI-FACTOR OPTIMIZATION

Glass coating films have been developed by many researchers in recent years. However, mass commercialization of this technology is still inefficient, and optimal methods are needed to produce affordable products. This paper introduces a film preparation method through, which a coating film is superimposed on silica glass by utilizing geothermal waste, a byproduct of geothermal power plants. Geothermal waste has been used as a silica precursor and modified using several silylation agents such as methyltriethoxysilane (MTMS), hexamethyldisilazane (HMDS), polydimethylsiloxane (PDMS), and surface-active agent (surfactant) cethyltrimethylammoniumbromide (CTAB). Design Expert 8.0.6 is used for optimization to find the desired product at the concentration of specific precursors and silane agents using contact angle responses. A model that consists of statistically significant variables can be generalized to a broad data range. The results of this study indicate that the glass surface coated with modified silica produces hydrophobic glass with contact angles up to 90° using the MTMS silylation agent.

Emulsifying composition for increase of oil recovery efficiency of high viscous oils

Nowadays, one of the more perspective technologies for oil recovery increase in the fields with heavy oils is formation of intrastratal emulsion. The paper presents the research on the increase of oil recovery in the fields with heavy oil via injection of combined composition based on the viscosity minimizer and surface active agent. Obtained composition allows significantly increase the stability of intrastratal emulsion, dramatically reducing the values of surface tension in the border of oil/water. The analysis of synergetic efficiency for suggested composition on the emulsion stability, surface tension and rheological properties has been carried out. More efficient concentrations of composition components have been specified. Obtained results have been justified with experiments on the replacement of high viscous oil from Galmaz field on the sand packed tubes of reservoir.

Mathematical Approach for Estimation of Alginate-Iron Salt Solutions Viscosity at Various Solid Concentrations and Temperatures

Alginate has been widely used in the pharmaceutical industries as tablet binder and disintegrant, release agent and controlled release drug delivery system. Whereas in the food industries, alginate is generally employed as thickener, emulsifier, stabilizer, texturizer, formulation aid, firming agent, flavor adjuvant, and surface-active agent. As one of the important raw materials in the functional food preparation, iron is hard to manage due to its vulnerability to oxidization, degradation and possesses a strong unique aroma. Considering its superior coating and release properties, alginate gel can be the best choice to preserve iron from various undesirable effects. Unfortunately, there has been lack information in the published literature to estimate the effect of temperature, concentration, and stirring time on the mechanical properties of alginate. Although many mathematical models have been developed based on these factors to predict the viscosity of the alginate-Fe solutions used as feed in spray drying application, no clear information have been reported for their accuracy. This study aims to examine four physical models for their suitability in estimating alginate-Fe solution viscosity, namely the Walther, Mark Houwink, Vogel – Tamman – Fulcher (VTF), and Intrinsic models. Prior to model validation, alginate-Fe solutions containing alginate: Fe (2:1) mass ratio were prepared. They were heated to desirable temperatures (30°, 45°, 60°, and 75°C), stirred for various stirring times (0 to 60 minutes), and subjected to viscosity measurement. The results exhibited that the viscosity of alginate-Fe solution with 5% alginate concentration stirred for 15 minutes at 30°C reached 320 cP. Whereas the viscosity of Alginate-Fe solution with 1% (m/m) concentration at the same temperature and stirring time was only 250 cP. This observation suggested that a higher alginate solution concentration leads to a higher the viscosity. As expected, a higher temperature and longer stirring time resulted in the decline of the Alginate-Fe solution viscosity. Although the proposed models demonstrated the similar trend, it can be concluded that the Walther model was proven to be the most accurate model used for the prediction of the Alginate-Fe solution viscosity compared to the other models as shown by its highest R2 value, which was 0.987.

Testing a Benchtop Wet-Milling Method for Preparing Nanoparticles and Suspensions as Hospital Formulations

In clinical practice, for elderly or pediatric patients who have difficulty swallowing, solid dosage forms such as tablets or capsules are crushed or unsealed, prepared as powder forms, and often administered as suspensions. However, because their dispersibility is poor, aggregation or precipitation occurs readily. Once precipitation and deposition happen, redispersion is difficult, which can limit patient and caretaker drug adherence. In this study, we attempted to prepare nanoparticles as a hospital formulation by a benchtop wet-milling method to obtain a suspension with high dispersibility. This is the first study to apply the wet-milling method to prepare the hospital formulation. We chose cefditoren pivoxil (CDTR-PI) as an experimental active pharmaceutical ingredient. CDTR-PI crystals were physically mixed with various water-soluble polymers such as polyvinylpyrrolidone, polyethylene oxide, hydroxypropyl cellulose, or hypromellose and wet-milled with a surface-active agent (sodium lauryl sulfate) under different conditions. The mean particle diameter of most of the samples was less than 200 nm. In FTIR spectra of ground samples, peak shifts suggesting inter- or intramolecular interactions between CDTR-PI and the other additive agents were not observed. Besides, the nanoparticle suspension had favorable dispersibility, as determined using a dispersion stability analyzer. Providing a suspension with high dispersibility makes dispense with the resuspension, the patient’s medication adherence would improve. These results show that suspended liquid formulations of active pharmaceutical ingredients could be obtained by the simple wet-milling method as hospital formulations.

Characterization of Lipopeptides Biosurfactants Produced by a Newly Isolated Strain Bacillus Subtilis ZNI5: Potential Environmental Application

Strain ZNI5, isolated from a hydrocarbon contaminated soil and identified as Bacillus subtilis after 16s rDNA sequence, grew and produced lipopeptides biosurfactants when cultured on glucose based media. After purification by anionic exchange chromatography and identification Reverse Phase High Performance Liquid Chromatography-Mass Spectrometry, the biosurfactant produced by ZNI5 were determined to be cyclic lipopeptides homologues. Four families of lipopeptides were identified by HPLC-MS analysis. They belongs to surfactin isoforms with molecular weights of 979, 993, 1007, 1021 and 1035 Da; iturin isoforms with molecular weights of 1028, 1042 and 1056 Da; Licheniformin with molecular weight of 1410 and newly identified isoforms named Inesfactin with molecular weights of 973 and 987 Da. Functional properties of the ZNI5 biosurfactant were studied. It was characterized as a powerful surface-active agent that decreases the surface tension of water from 72 mN/m to about 32 mN/m with a CMC value of 350 mg/L more efficient than chemical surfactants (Triton X100; CTAB and SDS). It has the capacity to disperse oil to about 80 mm at a concentration of 800 mg/L showing close efficiencies to the listed chemical surfactants. In addition, by studying the surface tension decrease capacity and the oil displacement activity, ZNI5 lipopeptide biosurfactant showed great thermal, pH and salts activity and stability enabling its use in the bioremediation fields and for diverse industrial applications.

Synergistic Effect of F–T Synthetic Wax and Surface-Active Agent Content on the Properties and Foaming Characteristics of Bitumen 50/70

The level of the properties of bituminous mixtures produced with water foamed bitumen relies on the optimum characteristics of the bitumen. One way to achieve the desired characteristics is to modify the bitumen with chemical additives before it is foamed. Bitumen 50/70 treated with a surface-active agent (SAA) at 0.2%, 0.4% and 0.6% and Fischer–Tropsch (F–T) synthetic wax at 1.5%, 2.0%, 2.5% and 3.0% was used in the tests. The effect of the modifiers was investigated by assessing bitumen properties (penetration, softening point, Fraass breaking point and dynamic viscosity at 60 °C, 90 °C and 135 °C) and foam parameters (maximum expansion—ER, half-life—HL). For statistical evaluation of the test results, models of the properties of bitumen 50/70 were developed as a function of the contents of F–T synthetic wax and SAA. It was found that 2.0% F–T wax and 0.6% SAA were optimum contents for achieving the desired standard properties and foam characteristics of the tested binder. The developed models allow determining the composition of the modified binder depending on the required foam characteristics for specific applications in road construction. The recommended composition of the chemical additives used to modify the binder was also established to ensure its optimum properties.

Ir-Ni based mono and bimetallic nanocrystals: synthesis, characterization and effect of cationic, anionic, and non-ionic stabilizers

Nickel based bimetallic nanocrystals, iridium-nickel play an imperative role in catalysis, electrocatalysis, and magnetic applications. In the present work Ir-Ni bimetallic nanoalloys were synthesized by modified polyol reduction method with different cationic, anionic, and non-ionic surface active agents like CTAB, SDS, TSC, and PVP. The non-ionic surface active agent PVP produced a better effect on nanoparticle size than cationic and anionic surfactants. The synthesized bimetallic nanocrystals were characterized by UV-Vis, XRD, FTIR, FESEM, and HRTEM techniques. XRD and FTIR verify the nature of synthesized bimetallic nanocrystals and the interaction between stabilizers and nanoparticles. HRTEM studies reveal that the PVP stabilized Ir-Ni (3:1) and Ir-Ni (1:1) bimetallic nanocrystals are small in size and less dispersed. Particle size range of these nanoparticles is from (1.77-2.36) nm. FESEM images show that nanoparticles are in quasi spherical shape. EDX analysis indicates that the resultant particles are core shell structure with Ni core and Ir shell.