Consolidation of volcanic tuffs with TEOS and TMOS: a systematic study

In this study, nine volcanic tuffs from Armenia, Germany and Mexico were treated with two commercially available consolidants on base of silicic acid ester, as well as different pretreatments with an anti-swelling agent and/or primer components. Prior to the treatment, the tuffs were analyzed regarding their petrography and mineralogy, with a greater focus on their clay mineral content. The effect of the consolidation was evaluated by comparative analyses of petrophysical properties and weathering behavior before and after the treatments. The main goals of this study were to identify a general suitability of different consolidating treatments for different types of tuff, evaluating tartaric acid as a primer component for tuff consolidation and to pursue the approach of finding a molecular answer for apparent tuff consolidation problematics, by testing a consolidation agent with smaller molecule sizes than current products on the market: tetramethoxysilane (TMOS).

Low-Temperature Mechano-Chemical Rubber Reclamation Using Terpinene as a Swelling Agent to Enhance Bond-Breaking Selectivity

Common swelling agents used in the mechano-chemical rubber devulcanization process usually require high temperatures to achieve satisfactory swelling effects, which results in severe production of pollutants and reduces the selectivity of bond scissions. This work presents an environmentally friendly swelling agent, terpinene, which can swell the rubber crosslink structures at low temperatures. Both a rubber swelling experiment and a rubber reclaiming experiment with a mechano-chemical devulcanization method are conducted to explore the swelling effects of terpinene. After soaking in terpinene at 60 °C for 90 min, the length elongation of the rubber sample reaches 1.55, which is much higher than that in naphthenic oil and is comparable to that in toluene. When adding 3 phr of terpinene for every 100 phr of waste rubber during the reclaiming process, the bond scissions exhibit high selectivity. After revulcanization, the reclaimed rubbers have a tensile strength of 17 MPa and a breaking elongation of 400%. Consequently, the application of terpinene as the swelling agent in the LTMD method can greatly improve the properties of reclaimed rubbers, thereby enhancing the dual value for the economy and environment.

Key Parameters to Tailor Hollow Silica Nanospheres for a Type I Porous Liquid Synthesis: Optimized Structure and Accessibility

Based on silica hollow nanospheres grafted with an ionic shell, silica-based type I porous liquids remain poorly exploited, despite their huge versatility. We propose here to explore the main synthesis step of these promising materials with a thorough characterization approach to evaluate their structural and porous properties. Modifying the main synthesis parameter, the mechanism of the spheres’ formation is clarified and shows that the calcination temperature, the surfactant concentration as well as the micelle swelling agent concentration allow tuning not only the size of the nanospheres and internal cavities, but also the silica shell microporosity and, therefore, the accessibility of the internal cavities. This study highlights the key parameters of hollow silica nanospheres, which are at the basis of type I porous liquids synthesis with optimized structural and porous properties.

Influence of TiO2 pigment particles on chromate ion transport in epoxy films

Transport of active species (i.e., ions) leaching from pigment particles incorporated in a polymer matrix is the main mechanism behind the anticorrosive performance of protective coatings. Understanding this mechanism is necessary for the effective design of the systems utilizing pigments less toxic than the most efficient chromate salts. It was demonstrated that anticorrosive pigment particles can themselves facilitate the transport of active species via the pathways formed after pigment leaching from a coating. It was also suggested that other paint components, e.g., certain additives, pigments, and fillers can be involved in the formation of transport pathways. Investigation of the possible influence of inert pigment (TiO2) on creating the pathways for chromate ion transport in polymer coatings was the primary objective of this work. In an experiment mimicking the transport of pigment species (i.e., chromate ions), a model epoxy coating containing particles of a single pigment (TiO2) was exposed to a chromate solution (aqueous, or with the addition of acetone as a polymer swelling agent). It was shown that the chromate ions can be transported in the epoxy film preferentially via the TiO2 particles/polymer matrix interface.

Solvent assisted dyeing of silk fabric using glycerine based eutectic solvent as a swelling agent

Purpose Dyeing of silk fabric was studied to increase dye uptake using eco-friendly glycerine based eutectic solvent (GES), which acts as a swelling agent. Design/methodology/approach The swelling behaviour of silk fabric in GES was analyzed using three-dimensional laser scanning microscope. Dyeing parameters such as time, temperature and GES concentration were optimized using design of experiments. Findings In total, 5.34 F-value and 0.0014 p-value of ANOVA represent that the model is significant. An optimized GES assisted dyeing was carried out with two different classes of dyes such as Acid Blue 281 and Acid Red 151 and further compared with that of conventional aqueous dyeing method. Originality/value At 70°C, silk fabric achieves desired colour strength after 35 min of dyeing (10 min lesser than conventional) using GES assisted dyeing method. % Dye exhaustion of GES assisted dye bath was carried out and found to be very good. Fastness properties such as washing, light and rubbing fastness of conventional and GES assisted dyed silk fabric showed comparable results.

Effect of the factors affecting high-performance p-aramid fibre dyeing and their optimization

Purpose This study aims to evaluate the dyeing of the p-aramid fibre with cationic dyes and investigate the effect of dyeing in the protection of the fibre from ultraviolet (UV) light. Design/methodology/approach P-aramid fabric has been dyed with cationic dyes using benzyl alcohol as swelling agent to promote the penetration of dye molecules into the fibre. The fabrics were evaluated against colour strength (K/S) value and colour fastness properties after dyed with cationic dyes using full factorial design. This design was used to study the effect of factors that affect the response variables as well as to study the interactions among the factors on response variable. The bursting strength, scanning electron microscopy analysis and X-ray diffraction analysis of undyed and dyed p-aramid fabric were performed before and after exposure to UV light to investigate the changes in mechanical behaviour. Findings The results show that the p-aramid fabric dyed with cationic dyes has good K/S values and good fastness properties. The exposure of undyed p-aramid fabric to UV light causes serious loss in strength over short duration i.e. 40 h. Dyeing of p-aramid fabric enhances the resistance to UV light which reduces the loss in strength. Originality/value Most of the work is patented and no one has done the process optimization for the industry, so this study offers promising outcomes concerning the dyeing of p-aramid fabric with enhanced shade depth and good colour fastness characteristics.

Fabrication of LDPE/PS interpolymer resin particles through a swelling suspension polymerization approach

A facile method to prepare low-density polyethylene (LDPE)/polystyrene (PS) interpolymer resin particles by swelling suspension polymerization without addition of extra swelling agent was developed. The polymerization temperature, polymerization time, and initiator concentration were investigated. Fourier transform infrared spectroscopy analysis confirmed that the LDPE/PS interpolymer resin particles were successfully prepared and a small amount of PS-g-LDPE existed in the resin. Scanning electron microscopy revealed that PS was uniformly distributed in the LDPE matrix, indicating excellent compatibility between PS and LDPE. The mechanical properties of LDPE/PS interpolymer resin were intermediate between PS and LDPE polymers.

Formulation and Evaluation of Pulsatile Drug Delivery System of Zafirlukast

In the current scenario of pharmaceutical research much attention has been focused on patients health in terms of therapeutic efficacy and economical standards (price factor).The formulation design consist of core tablets designed by direct compression method. Core tablets were coated with an naturally occurring swelling agent (carbopol & Karaya gum). Evaluation studies were performed for prepared pulsatile tablets hardness. In in vitro release profile of 6 hours study in first 5 hours it shows minimum drug release and at the end of six hours rapid and transient release was observed. Stability studies proved that coating of tablets seems to decrease the effect of temperature and moisture on degradation of Zafirlukast. The pulsatile release has been achieved from tablet over a 7-8 hour period.