ISO 304:1985 界面活性剤—液膜を作成することによる表面張力の決定 | ページ 2

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting.

International Standard ISO 304 was prepared by Technical Committee ISO/TC91, Surface active agents.

This second edition cancels and replaces the first edition (ISO 304-1978), of which it constitutes a minor revision.

Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated.

0 Introduction

Surface tension is a fundamental property of liquids in general and aqueous solutions of surface active agents in particular.

The measurement of this characteristic, however, does not allow, in the case of solutions of surface active agents, any suppositions as to their detergency, wetting, foaming, emulsifying activities, etc. Indeed, no connection can be established between the performance properties of the surface active agents and the surface tension of their solutions.

1 Scope and field of application

This International Standard specifies a test method for the determination, by drawing up liquid films, of the surface tension of aqueous or organic solutions of surface active agents and mixtures containing one or more surface active agents.

It also applies to the measurement of surface tension of pure liquids or solutions other than those mentioned above.

• a) methods by drawing up liquid films by a plate, stirrup or ring:
• b) methods for measuring the rise of liquid in a capillary tube;
• c) maximum ball pressure method;
• d) drop weight method;
• e) drop or sessile ball method;
• f) suspended drop method;
• g) dynamic methods based on measurements of flow characteristics;
• h) methods which study the waves produced in capillary jets.

The methods based on drawing up liquid films have notable advantages in the simplicity of their procedure and the commercial availability of highly automatic appliances.

2 References

Annex C

Bibliography
(This annex does not form an integral part of the Standard.)

For information concerning the correction factor, ƒ, in the formula for the calculation of surface tension in the case where the ring is used (see 7.1.3), the following works may be consulted: