[ Evidence and evaluation · not a laboratory ]
Nanotechnology
Small things behave differently, and that fact is used to sell a great deal. These pages explain the mechanisms that are real, show what a measurement of a nanomaterial actually measures, and give you the questions that separate a result from a claim about it.
Maha Strategies makes no materials, runs no synthesis or characterisation, and certifies nothing. What we publish is explanation, method and the sources we read, each with the passage we read it at.
Start here
- What “nanoscale” means, and why the 1–100 nm range is a convention
The nanoscale is conventionally about 1 to 100 nanometres. That range is an agreed boundary for programmes and regulation, not a physical threshold where new behaviour switches on.
- Why the same material behaves differently when it is small
As a particle shrinks, the fraction of its atoms sitting at the surface rises steeply. Surface atoms are where dissolution, catalysis, adsorption and aggregation happen, so the same chemistry can behave differently at a smaller size.
- Reading a nanomaterial datasheet or demonstration claim
Read a vendor claim for what was measured, on which batch, by which method, against which control. A performance number without those four is a description, not evidence.
All 17 explanations
- What “nanoscale” means, and why the 1–100 nm range is a convention
The nanoscale is conventionally about 1 to 100 nanometres. That range is an agreed boundary for programmes and regulation, not a physical threshold where new behaviour switches on.
- Why the same material behaves differently when it is small
As a particle shrinks, the fraction of its atoms sitting at the surface rises steeply. Surface atoms are where dissolution, catalysis, adsorption and aggregation happen, so the same chemistry can behave differently at a smaller size.
- Nanomaterial classes describe shape, not behaviour
Grouping materials as particles, tubes, sheets or dots organises a conversation about geometry and synthesis. It does not let you transfer a property, a hazard or a performance result from one member of the group to another.
- Top-down patterning and bottom-up synthesis answer different questions
Top-down methods carve structure out of a larger material; bottom-up methods grow it from molecular precursors. The choice sets what you can control, what varies, and what evidence you need.
- Every characterisation method measures its own quantity
Electron microscopy, light scattering and gas adsorption do not measure “the size” of a material. Each measures a different physical quantity, under different assumptions, and the numbers are not interchangeable.
- Report a nanomaterial size the way a measurement is reported
A single number is not a size. Report the measurand, the method, the distribution and an uncertainty with its basis, or the result cannot be compared with anyone else’s.
- One batch is one batch
A result obtained on a single synthesised batch describes that batch. Reproducibility claims need either several independent batches or an explicit statement that they were not tested.
- Structure–property claims need the mechanism, not the correlation
A correlation between a structural parameter and a performance number supports a structure–property claim only when the mechanism that connects them is stated and the confounders are excluded.
- What changes between a gram and a kilogram
Scale-up is not the same synthesis performed for longer. Mixing, heat transfer, addition rate and cleaning all change with vessel size, and they are the variables that set the distribution.
- What an exposure or safety study does and does not settle
A toxicology or exposure result applies to the material, the dose, the route and the model it used. Extending it to a different particle, coating, medium or exposure route is a new claim.
- Regulatory status is not a safety finding, and medical claims have their own bar
Being reportable under TSCA, listed in an inventory, or addressed by an FDA guidance describes a process a product is in. None of them is a statement that a material is safe or effective.
- Reading a nanomaterial datasheet or demonstration claim
Read a vendor claim for what was measured, on which batch, by which method, against which control. A performance number without those four is a description, not evidence.
- A runnable surface-area-to-volume calculation, and what it cannot tell you
This section ships a small deterministic calculator for idealised shapes. It shows the geometry clearly and refuses to imply anything about reactivity, toxicity or performance.
- What a coating changes, and why the surface is usually the variable that moved
A ligand or coating changes what the outside of a particle is, which is what solvents, cells and other particles actually meet. In a biological medium the engineered surface is quickly covered by adsorbed proteins, so the particle acquires a second identity the designer did not specify.
- Quantum confinement: a real size effect, and what an optical size measurement assumes
Confinement is one of the few places where making a semiconductor smaller changes a property for a well-understood physical reason rather than by changing surface area. The band gap widens as the crystal shrinks, which is why a size change shows up as a colour change.
- Nanomaterial sensors: high sensitivity is the easy half, selectivity is the hard half
A large, reactive surface makes a nanomaterial an excellent transducer, which is why sensitivity figures are easy to produce. The same non-specific surface chemistry is why the response is rarely specific to one analyte.
- Reading an energy-storage claim: the numbers that must travel with a capacity
A capacity or energy-density figure means nothing on its own. It is a measurement made under conditions, and the conditions are what decide whether it has any bearing on a practical cell.
Run the arithmetic yourself
The section ships a unit-aware surface-area-to-volume calculator for idealised particles, with its assumptions and dimensional checks printed beside every result. It refuses zero dimensions, unsupported units and zero density rather than returning a number that looks plausible.
node --experimental-strip-types scripts/nanoscale-surface-area.ts \ --shape sphere --size 10 --unit nm --density 4 --density-unit g/cm3
Geometry predicts area, not reactivity, toxicity or performance — see what the calculator cannot tell you.
Related sections
- Semiconductor process and supplier map — top-down patterning, which this section does not restate.
- Neuromorphic and biocomputing — memristive and in-memory devices built from these materials.
- Physical AI — the evaluation discipline applied to learned systems that act.
- Robotics evidence and evaluation — measurement and evidence records for machines.
Sources read for this section
- National Nanotechnology Initiative — About Nanotechnology ↗
Read at: About Nanotechnology, opening paragraph; “How small is nano?” · inspected 2026-09-19
- NIOSH — Approaches to Safe Nanotechnology: Managing the Health and Safety Concerns Associated with Engineered Nanomaterials (DHHS/NIOSH 2009-125) ↗
Read at: §4.1 Nano-objects and §4.2 Ultrafine Particles, p. 8; §8.3.5 Respirators, pp. 43–44 · inspected 2026-09-20
- NIOSH Current Intelligence Bulletin 63 — Occupational Exposure to Titanium Dioxide (DHHS/NIOSH 2011-160) ↗
Read at: Executive summary, p. iii · inspected 2026-09-20
- NIOSH Current Intelligence Bulletin 65 — Occupational Exposure to Carbon Nanotubes and Nanofibers (DHHS/NIOSH 2013-145) ↗
Read at: Publication summary — recommended exposure limit · inspected 2026-09-20
- EPA — Control of Nanoscale Materials under the Toxic Substances Control Act ↗
Read at: Nanoscale Materials; Regulatory Approach; Information gathering rule; Reporting under the rule · inspected 2026-09-19
- FDA — Nanotechnology Guidance Documents ↗
Read at: List of guidance documents, including “Considering Whether an FDA-Regulated Product Involves the Application of Nanotechnology”, “Safety of Nanomaterials in Cosmetic Products”, and “Drug Products, Including Biological Products, that Contain Nanomaterials” — each listed as final guidance · inspected 2026-09-20
- Akhter et al. — Impact of Protein Corona on the Biological Identity of Nanomedicine: Understanding the Fate of Nanomaterials in the Biological Milieu (Biomedicines, 2021) ↗
Read at: Introduction; “Types of Coronas and the Biological Identity of NPs”; “Impact on the Physico-Chemical Characteristics”; “Drug Targeting and Cellular Uptake in the Biological Milieu” · inspected 2026-09-20
- Ferreira et al. — Size-dependent bandgap and particle size distribution of colloidal semiconductor nanocrystals ↗
Read at: Abstract; §1 Introduction · inspected 2026-09-20
- Liu et al. — Advancements and Strategies for Selectivity Enhancement in Chemiresistive Gas Sensors (Nanomaterials, 2025) ↗
Read at: §1 Introduction; §2 Gas Sensing Mechanism; §3.1.2 Defects Generation · inspected 2026-09-20
- Lin, Liu, Ai and Liang — Aligning academia and industry for unified battery performance metrics (Nature Communications, 2018) ↗
Read at: Introduction; “All performance metrics matter”; “The way forward” · inspected 2026-09-20
- NIST Technical Note 1297 — Guidelines for Evaluating and Expressing Uncertainty ↗
Read at: §2 Classification of components of uncertainty; §3 Type A; §4 Type B; §7 Reporting uncertainty · inspected 2026-09-19
Nothing here is a safety assessment, an exposure limit, a product approval or medical advice. Regulatory questions belong to the relevant agency; workplace exposure belongs to qualified occupational-health practice.