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Published in Michael L. Madigan, HAZMAT Guide for First Responders, 2017
Laboratory glassware refers to a variety of equipment, traditionally made of glass, used for scientific experiments and other work in science, especially in chemistry and biology laboratories. Especially borosilicate glass, pioneered by Otto Schott, or soda lime glass is the preferred glass type for scientific experiments and other work in science, especially in chemistry and biology laboratories.
Surface Properties of Glass Fibers
Published in M. J. Schick, Surface Characteristics of Fibers and Textiles, 2017
Glass, in the most general sense, consists of solid, noncrystalline materials. Since these materials lack a well defined melting point, they are sometimes considered liquids which are supercooled at room temperature [1]. The term, however, is most commonly used to refer specifically to the silicate class of glasses. These are inorganic, room-temperature glasses consisting of a three dimensional network of silicon and oxygen of empirical formula SiO2, with various inorganic additives which help determine their physical properties. For the case of the most common glasses, called “soft glass, “ or “soda-lime glass,” the additives are alkali metal silicates. They disrupt the continuity of the silica network sufficiently to lower the softening point to a convenient region of approximately 400°C, at which the glass can be worked into a variety of desired shapes. Borosilicate glasses, known widely by the brand name “Pyrex, “ can consist, for example, of approximately 80% SiO2, 13% B2O3, 4% Na2O, 2% A12O3, and 1% Li2O and K2O. Their chief characteristic is high resistance to thermal shock, which makes them uniquely suitable for a variety of applications, including laboratory glassware and kitchen cooking ware. The most common glass composition for drawing fibers for use in textiles or structural materials is a borosilicate known as “E glass” [2]. A typical E-glass composition would be, for example, 54% SiO2, 17% CaO, 15% A12O3, 8% B2O3, and 5% MgO. A recent innovation has involved drawing fibers from a melt of glass with the composition 65% SiO2, 25% A12O3, and 10% MgO, which yields a product with especially high tensile strength known as “S glass” [3]. These find use in glass-fiber-reinforced plastics for high performance materials. The actual surface concentrations of the components of fibers will vary from the bulk composition according to the ability of each to lower the surface free energy by diffusing to the surface while the fiber is still in the molten state (surface segregation). Regardless of the actual composition of this fiber surface, however, it has been found that realistic approximations of the surface properties of boro-silicates relevant to most uses are obtained by assuming that they are determined by the siliceous portion of the surface.
Effects of temperature on viscosity, stability, and microstructure of water-in-biodiesel microemulsions
Published in Journal of Dispersion Science and Technology, 2023
Alexander Ashikhmin, Mikhail Andropov, Maxim Piskunov, Pavel Strizhak, Vyacheslav Yanovsky
The samples of fuel microemulsions were prepared using the Daihan Scientific MSH-20D magnetic stirrer (rotation rate was from 80 to 1500 rpm, the minimal step of rate changing was 5 rpm) and glass laboratory glassware. Each of the components was sequentially placed in a sealed glassware using the mechanical dispensers, then stirring was carried out using the magnetic stirrer until the homogeneous composition (visually transparent liquid) was obtained. When preparing the fuel microemulsions, a strict sequence of mixing the components was observed. First, the components of the first category (D or the mixture of D and RO) were mixed with the pre-prepared emulsifier (Smix) at a rate of ∼300 rpm, then distilled water was added; the stirring rate was increased up to 1250 rpm. The stirring time of the sample at the rate of 1250 rpm was 5 min. The samples of microemulsions were prepared at room temperature. The component composition of the fuel microemulsions is presented in Supplementary materials (see Section Tables).
Preparation and characterization of graphene oxide/O-carboxymethyl chitosan (GO/CMC) composite and its unsymmetrical dimethylhydrazine (UDMH) adsorption performance from wastewater
Published in Environmental Technology, 2023
Jun Su, Ying Jia, Ruomeng Hou, Yuanzheng Huang, Keke Shen, Zhaowen Hao
The chemicals used in the experiments were all analytically pure. UDMH [(CH3)2NNH2, ≥98 wt.%] was purchased from Qinghai Liming Chemical Factory. Concentrated sulfuric acid (H2SO4, 98 wt.%) and hydrochloric acid (HCl, 37 wt.%) were purchased from Xi’an Doumen Chemical Plant. Graphite powder was purchased from Tianjin Dingshengxin Chemical Co., Ltd. Potassium permanganate (KMnO4) was purchased from Harbin City Xinchun Chemical Plant. Hydrogen peroxide (H2O2, 30 wt.%), sodium nitrate (NaNO3), CS, and monochloroacetic acid were purchased from Sinopharm Chemical Reagent Co., Ltd. Sodium hydroxide (NaOH) and isopropanol ((CH3)2CHOH) were purchased from Shanghai Titan Technology Co., Ltd. Deionized (DI) water was used to clean laboratory glassware and prepare test solution.
Crystallization of struvite in the presence of calcium ions: Change in reaction rate, morphology and chemical composition
Published in Cogent Engineering, 2022
D. S. Perwitasari, S. Muryanto, J. Jamari, A. P. Bayuseno
The struvite crystallization experiments were carried out using an agitated laboratory glass beaker of 200 ml volume. Anhydrous magnesium chloride (MgCl2) and ammonium dihydrogen phosphate (NH4H2PO4) crystals (Merck, AR grades) were used for the struvite crystallization providing ions: Mg2+, NH4+, and PO43− necessary for the reaction. Moreover, a stock solution concentration of 0.17 M each was prepared from those chloride and phosphate powder crystals, which were analytically weighed (WANT Balance, FA-N Series, 0.0001 g) and then diluted separately with distilled water. The dissolution was carried out using standard laboratory glassware (graduated cylinders, volumetric flasks, and other glass apparatus of various sizes). In view of the pH solution being affected by absorbing CO2 from the air into the solution due to long-standing distilled water, boiling the distilled water was necessary and left to cool in a closed container prior to the dissolution. Next, a pH of 9.00 in the mixed solution was set up by drop-wise addition of 0.2 N KOH (Bhuiyan et al., 2007; Bhuiyan, Mavinic, Koch et al., 2008b; Doyle & Parsons, 2002). The pH adjustment was required for struvite crystallization that occurs only in basic conditions. In the experiment, the chemical compositions of crystal-forming solutions are presented in Table 1.