# Materials Science — Sub-Hub Materials science is the study of how the internal structure of matter — its atoms, bonds, crystals, grains, and phases — determines what a material can do: how strong it is, how it conducts or insulates, how it corrodes, how it fails, and how it behaves in a human body or an ecosystem. It sits at the intersection of Physics and Chemistry and feeds directly into engineering. The discipline's organizing idea is the *structure–property–processing–performance* relationship: change the structure (alloy a metal, cross-link a polymer, dope a semiconductor) and you change the properties, and you can engineer the structure by controlling how the material is processed. That sounds like a purely technical field, and at its core it is. But materials are where abstract science becomes the physical substrate of everyday life — the pipes that carry drinking water, the insulation in a wall, the chips in a phone, the steel in a bridge, the battery in a car, the armor on a soldier. That is exactly why materials science is so heavily entangled with **law, business, health, safety, and national security**, and why it gets its own sub-hub in this vault. The KB's interest here is less in crystallography for its own sake than in the places where a material's properties collide with public policy: the toxics that became the longest mass torts in American history, the minerals that drive trade wars and supply-chain coercion, the failure modes that kill people when regulation is captured, and the materials that underwrite the [[Defense Tech Ecosystem]]. This sub-hub sits under the [[Science]] discipline hub alongside Chemistry, Physics, and the others. It deliberately **links out rather than duplicates**: the deep chemistry of plastics lives in Polymers; semiconductor device physics and supply chains live in [[Semiconductor]], [[Semiconductor Fabrication]], and [[Rare Earth Elements]]; battery cells live in [[Lithium-Ion Battery]]; and forever-chemicals live in [[PFAS and Forever Chemicals]]. This folder holds the materials-science framing and the applied law/business/health/safety angle that ties them together. ## Foundations — How Materials Work The thin technical backbone the rest of the folder rests on. - Classes of Materials — metals, ceramics, polymers, composites, semiconductors, biomaterials; the structure–property–processing–performance idea - Materials Failure and Safety — fatigue, fracture, creep, brittle failure; the engineering-disaster lineage and what happens when safety margins meet captured regulators - Corrosion — the slow, costly degradation that links the Flint pipes to collapsing bridges and the trillion-dollar maintenance bill nobody wants to pay ## Toxic Materials, Health, and the Law The materials that became public-health crises and the legal machinery that grew up around them. - Asbestos — the "magic mineral" that became the longest-running mass tort in U.S. history; the bankruptcy-trust workaround - [[Lead]] — paint, pipes, and gasoline; a century of industry denial from the Kehoe era to Flint - Silica and Silicosis — the engineered-stone epidemic killing young countertop workers; a regulation racing a material - [[Vinyl Chloride and PVC]] — fifty years of concealed carcinogenicity, and the East Palestine derailment - Mercury (element) — the coal-plant neurotoxin, the thimerosal myth, and the 2026 rollback of the mercury rule - Flame Retardants — a fake "safety" movement built by tobacco and chemical interests - Hexavalent Chromium — the Erin Brockovich/PG&E toxin and the missing drinking-water standard - Nanomaterials — engineered matter at the nanometer scale, racing ahead of a regulatory framework built for bulk chemicals - [[Toxic Substances Control Act]] — the 1976 law that grandfathered in 60,000 untested chemicals and the regulatory capture that keeps it weak - Product Liability and Toxic Torts — the legal doctrines (design defect, failure to warn, strict liability) through which materials harms reach the courts See also [[Endocrine Disruptors]] (in Concepts) — the hormone-disrupting chemicals (BPA, phthalates, flame retardants, PFAS) where environmentalist and right-wing "they're poisoning us" concern converge. ## Strategic Materials, Business, and National Security The materials that drive industrial policy, trade conflict, and supply-chain coercion. - [[Conflict Minerals]] — tin, tungsten, tantalum, and gold; Dodd-Frank Section 1502 and the limits of disclosure-based regulation - Steel and Aluminum — [[Section 232]] tariffs, deindustrialization, and the politics of "strategic" metals - Lithium and Battery Materials — the mineral supply chain behind the energy transition, and the mining politics it ignites - Advanced Composites and Defense Materials — carbon fiber, Kevlar, titanium, and superalloys; the materials underwriting the [[Defense Tech Ecosystem]] - [[Permanent Magnets and the Rare-Earth Supply Chain]] — the NdFeB magnets that became the central chokepoint of the 2025 US–China trade war - Gallium, Germanium, and Compound Semiconductors — the radar/infrared materials China banned to the US in 2024 - Titanium and the Aerospace Supply Chain — the jet-and-missile metal the West still buys from Russia's VSMPO - [[Uranium]] — enrichment, the 2024 Russian-uranium ban, and the HALEU bottleneck - Strategic and Critical Materials Stockpile — the National Defense Stockpile and the cheap insurance the US sold off See also [[Critical Minerals]] and [[Rare Earth Elements]] for the broader minerals-supply and China-dependence picture, which this folder cross-links rather than restates. ## Infrastructure and the Built Environment - Concrete and Cement — the most-used material on Earth after water; an ~8% slice of global CO2 and a hidden infrastructure liability - Glass and Optical Materials — from the windowpane to the optical fiber that carries the internet; broadband and undersea-cable security ## Manufacturing, Recycling, and Frontier Materials How materials are made, re-made, and hyped — and the politics each process triggers. - [[3D Printing and Additive Manufacturing]] — manufacturing-as-information; the ghost-gun problem and the limits of regulating a file - Recycling and the Circular Economy — why metals recycle and plastics downcycle; extended producer responsibility vs. voluntary programs - Graphene and 2D Materials — the wonder-material hype cycle as a lens on science funding and national R&D competition - Solid-State Batteries — the next-generation battery racing toward ~2027 mass production; hype, leapfrog hopes, and shifted dependencies - Superconductors — zero-resistance materials, fusion magnets, and the LK-99 episode as a hype/verification case study ## Boundary Notes — Link, Don't Duplicate - **Plastics chemistry** → Polymers (in Chemistry): monomers, polymerization, microplastics, the recycling myth, PFAS-as-polymer. - **Semiconductors as devices** → [[Semiconductor]], [[Semiconductor Fabrication]] (in Terminology): chips, fabs, the chip war. This folder treats silicon, gallium, and rare earths as *materials*; the device and supply-chain story lives there. - **Forever chemicals** → [[PFAS and Forever Chemicals]] (in [[Earth Sciences]]): the canonical PFAS page; Nanomaterials and [[Toxic Substances Control Act]] cross-link it. - **Consumer-hardware angle** → [[Right to Repair]], [[Planned Obsolescence]] (in Terminology): the design/business face of materials choices. ## Elements and extraction Folded in from the former Chemistry folder on 2026-09-30; this folder is now Materials and Resources. - [[Cobalt]] — the battery metal and the Congo supply chain - [[Gold]] — the monetary metal and gold-bug politics ## See Also - [[Science]] — parent discipline hub - Chemistry — sibling sub-hub; the molecular layer beneath materials - Physics — sibling sub-hub; the bonding and mechanics beneath materials - [[Defense Tech Ecosystem]] — the largest single consumer of advanced materials in the KB - [[EPA]] — the regulator at the center of most materials-health stories - [[Merchants of Doubt]] — the industry doubt-manufacturing playbook that recurs across asbestos, lead, and PFAS