Reactor material is a three-way decision: what light must pass, what chemistry must be survived, and what pressure must be contained. The common options, glass, quartz and stainless steel, each win on different legs of that triangle.
The default: excellent transmission through the visible and into the near-UV (roughly 350 nm cutoff), strong resistance to aqueous acids and moderate bases, adequate for ambient-pressure work and modest pressure in proper designs. Weaknesses: hydrofluoric acid and hot concentrated alkali attack it, and its pressure ceiling is structurally limited by design rather than material.
The optical upgrade: transmission deep into the UV, mandatory for UV-driven photochemistry below the glass cutoff. Chemically it resembles glass's strengths, and it costs more and ships more brittle, treat quartz windows as precision components, with the handling that implies.
The pressure-and-solvent champion: high-pressure capability, tolerance of organic solvents that craze or extract from polymers, and structural toughness. Weaknesses: it is opaque, so windows (glass or quartz) become the pressure-limiting elements; chloride chemistry pits it; and strong acids need the right alloy class, standard grades are not universal.
Check the full solvent and catalyst system, not just the main reagent, the sacrificial agent often does the corroding. Verify seals and O-rings against the same list, elastomers fail chemically long before metal does. And document material choices in the methods section: reactors are chemistry too.
Perfectlight offers glass, quartz-windowed and steel photoreactors; see the reactor line and solutions.
