Analysis And Development Of The Difference Between The Broad Concept And Applicability Of Foaming Agents
(1) General concept of foaming agent
Foaming agents are substances that can produce large amounts of foam in aqueous solutions when mechanical force is introduced into the air. Such substances are surfactants or surface-active substances. The former such as anionic surfactants, cationic surfactants, nonionic surfactants, etc., and the latter such as animal protein, vegetable protein, pulp waste liquid, etc.
Foaming agents all have high surface activity and can effectively reduce the surface tension of the liquid. A double electron layer is arranged on the surface of the liquid film to surround the air, forming bubbles, and then single bubbles form foam.
The essence of foaming agent is its surface active effect. Without surface activity, foaming cannot occur and it cannot become a foaming agent. Surface activity is the core of foaming.
(2) Broad concept and narrow concept of foaming agent
Foaming agent has two concepts, broad and narrow. There is a certain difference between these two concepts, which can be distinguished between not applying foaming agent and applying foaming agent.
① Generalized foaming agent
Foaming agents in a broad sense refer to all surfactants or surface-active substances whose aqueous solution can produce a large amount of foam when it is introduced into the air. Since most surfactants and surface-active substances have the ability to generate large amounts of foam, the broad term foaming agent includes most surfactants and surfactants. Therefore, the scope of foaming agents is very large, with many types, performance and quality vary greatly, and the range of selectivity is also very wide.
Generalized foaming agents do not have strict requirements on technical properties such as foaming multiple (foaming capacity) and foam stability (availability). It just means that it has a certain ability to generate a lot of foam. The jury is still out on whether the foam produced will serve a practical purpose.
② Foaming agent in a narrow sense
A foaming agent in a narrow sense refers to a foaming agent that can not only produce a large amount of foam, but also has excellent foaming performance, can meet the technical requirements for foaming of various products, and can truly be used to produce actual surfactants or surfactants. . Active substances. The biggest difference between it and general foaming agents lies in its application value. What reflects its application value is its excellent performance. Its excellent properties are: extremely strong foaming ability, large foam output per unit volume, very stable foam, long-term use without defoaming, fine foam, and good compatibility with the medium used.
Foaming agents in a narrow sense are foaming agents actually used in industry. Generally speaking, the foaming agents that people often refer to refer to this type of foaming agent in a narrow sense. Only foaming agents in a narrow sense have research and development value.
(3) Concept of cement foaming agent
Cement foaming agents belong to a category of narrow foaming agents, not all narrow foaming agents. In the narrow sense of the foaming agent, only a very small part can be used in foam concrete, and the quantity is very small. This is determined by the characteristics and technical requirements of foam concrete.
In industrial production and daily civilian use, the uses of foaming agents vary widely, and different application fields have different technical requirements for foaming agents. For example, the foaming agent used in fire extinguishers only requires its instantaneous foaming capacity and oxygen barrier ability, but does not require its high stability and fineness. Another example is flotation foaming agent for mining, which only requires strong adsorption of target substances and good foaming power, but does not have high requirements on foaming multiple and foam stability. I won't list them one by one. Foaming agents are currently used in almost every industrial field and have a wide range of uses. Different industries obviously have different performance requirements for foaming agents. A blowing agent that can be used in one industry cannot be used in another industry or does not work well. Similarly, the foaming agent used in foam concrete puts forward technical requirements for concrete foaming. In addition to being able to produce large foams, special attention is also paid to the stability of the foam, the fineness of the foam, and the adaptability of the foam to cementitious materials such as cement. There are very few narrow blowing agents that can meet this requirement. Most foaming agents cannot be used in the actual production of foamed concrete. Therefore, the foam concrete foaming agent must be a small amount of surfactant or surface-active substance that meets the above technical requirements.
It is precisely because of the conceptual ambiguity that many people have fallen into great misunderstandings in practical applications, confusing the two different concepts of "foaming agent" and "foam concrete foaming agent". When used, the result is that there is no foaming effect and foam concrete that meets the requirements cannot be produced. Therefore, it is very necessary for us to understand these concepts and their differences, so that we can avoid many misunderstandings and avoid many detours during the use of foaming agents. In fact, many things on the market named "foaming agents" are not foam concrete foaming agents. Everyone should understand this.