"Glass" - what is it, definition of the term
«Glass» is a hard, brittle, optically transparent amorphous solid composed chiefly of silicon dioxide; it forms when molten silica mixtures are cooled rapidly enough to prevent crystallization, yielding a disordered atomic network that confers low electrical conductivity, chemical resistance, and the ability to be shaped by heating and annealing.
Detailed information
The transparent silica‑based material consists of a non‑crystalline network of silicon dioxide, often modified with sodium, calcium, or aluminum oxides to adjust viscosity and durability. Production begins with raw sand fused at temperatures above 1500 °C; additives melt into the molten mass, yielding a homogeneous liquid that can be shaped by blowing, pressing, or casting. Rapid cooling prevents crystal formation, preserving the amorphous structure that imparts optical clarity and brittleness.
Physical characteristics include a high refractive index (≈1.5), low thermal conductivity, and a coefficient of thermal expansion that varies with composition. Chemical resistance is notable against most acids, while alkaline solutions can etch the surface. Mechanical strength improves through tempering, which introduces compressive stresses on the exterior layer.
Key applications relevant to arthropod research:
- Microscope slides and cover slips provide flat, inert surfaces for mounting specimens of ticks, true bugs, lice, and fleas, allowing high‑resolution observation without chemical interference.
- Observation chambers constructed from clear vitreous compounds enable live monitoring of insect behavior, facilitating studies of locomotion, feeding, and mating under controlled illumination.
- Traps employing transparent containers reduce visual cues that might deter small ectoparasites, increasing capture efficiency in field surveys.
- Storage vials made from this material preserve collected specimens, maintaining humidity and preventing contamination while allowing visual inspection.
Manufacturing tolerances ensure dimensions within ±0.01 mm, essential for fitting standardized microscope accessories. Surface treatments such as anti‑reflective coatings reduce glare, enhancing image contrast during photomicrography of minute anatomical features.