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Research draft

surface tension

vr.tr.surface-tension · PHY.FLW

Let an agent handle surface tension with values, units, temperature dependence and applications.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent handle surface tension with values, units, temperature dependence and applications.

The tendency of a liquid surface to contract to the smallest possible area, caused by cohesive forces between molecules, measured as force per unit length or energy per unit area.

What it is for: Explaining droplets, capillarity, bubbles and wetting, and designing detergents, inks and coatings.

It can be measure it with tensiometers; reduce it with surfactants; use it in capillary and microfluidic designs; predict droplet and bubble behaviour.

Distinguishing features

Property of liquid interfaces

Decreases with temperature

Lowered by surfactants

Governs capillary action

What it looks like

Beading droplets, floating light objects, curved menisci.

Physical character

water at 20 C: 72.8 mN/m

ethanol at 20 C: 22.3 mN/m

How it is recognised

Spherical droplets and menisci

Insects walking on water

Values in mN/m

Related models

is a kind of - material property

physical quantity

is lowered by - detergents

surfactant

causes - phenomenon

capillary action

is measured in - unit

N/m

In practice

Families and kinds

liquid-gas surface tension

interfacial tension between liquids

dynamic surface tension

Identifiers

SI unit N/m newton per metre

Standards and regulation

ISO 304 for surface tension of surfactant solutions

Failure modes and hazards

Ignoring temperature and contamination effects

Unit confusion (mN/m vs dyn/cm, which are equal)

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.surface-tension

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Value How strong.

Values need conditions.

Number

mN/m.

Value

Surface tension value.

  1. What is its surface tension, at what temperature? measurement
  2. From which source? provenance

Interface

Which phases.

Interface

Interface.

  1. Between which phases is it measured? definition
  2. Is it static or dynamic? definition
Measurement Methods.

Methods differ.

Method

Tensiometry.

Method

Method.

  1. Which method measured it? provenance
  2. How precise? measurement

Contamination

Purity.

Purity

Contamination effects.

  1. Could contamination have affected the value? boundary
  2. How was purity ensured? provenance
Effects What it causes.

Effects matter in practice.

Capillarity

Rise in tubes.

Capillarity

Capillary effects.

  1. How does it affect capillary rise here? measurement
  2. What role does wetting play? definition

Droplets and bubbles

Shapes.

Droplets

Droplet behaviour.

  1. How does it shape droplets or bubbles? definition
  2. What happens at small scales? definition
Control Changing it.

Surfactants and temperature change it.

Surfactants

Detergents.

Surfactants

Surfactant effects.

  1. How much do surfactants lower it? measurement
  2. What is the critical micelle concentration? measurement

Applications

Inks, coatings.

Applications

Applications.

  1. How is surface tension controlled in this product? definition
  2. What are the environmental effects of surfactants? boundary

What the second pass must settle

  • Should interfacial tension be a separate entry?
  • How should temperature dependence be recorded?
  • How should measurement methods be linked?