First, and perhaps most importantly, note that the osmosis owes his life, that perhaps this way sounds very serious, but we see that the first studies osmosis or as it was called then osmotic process was developed on the principles of medicine, biology, physiology, etc. We'll have to go back to the late nineteenth century, to find the first explanation, of course, always based on the concept of absorption and therefore in the process of food in the cell. physiologists in the nineteenth century, and pointed out: "The absorption osmotic flow through the outer membrane that protects the cell, it allows food and therefore the maintenance of life processes cell or a unicellular organism. "
Gradually, the disciplines related to medicine and biology have been giving way to physics, chemistry and mathematics in an attempt to explain the osmotic phenomenon, since it is linked concepts such as concentration, solutes, solvents and energy. Are the laws of thermodynamic equilibrium which come closest to a scientific description of the phenomenon, but without it, as we shall see.
insist that despite over 150 years to the discovery of the phenomenon of osmosis , its real physical meaning remains hidden even today.
Enormous growth "around" the phenomenon itself, even as we know, applications have been developed much of the phenomenon, but there is no scientific explanation of the phenomenon that has been fully accepted there, yes, many "approaches" scientific .
osmosis appears linked to many theories and phenomena: theory of solutions, equilibrium thermodynamic theory, diffusion barriers to flow or, rather, semi-permeable membranes, but the reality is that we explain the results, but no a theory that explains the osmotic flow.
If it is true that as in many other cases, scientists have avoided, for now, the reason for the phenomenon and have gone straight to what and fully predictive models have achieved great practical applications of a phenomenon that we can not explain very well.
The reason for this behavior is that once you discover the semi-permeable membranes and how they behave with different solutions, it is easy to project with images practical applications of engineering itself that is able to perform.
The huge success of the use of such membranes in multiple processes should not mislead us to know why, really not known, it is close, yes, and the day to establish the mathematical model to justify the reality, but that has not yet arrived.
At this point, before entering the history osmosis, it should be noted that the scope of semi-permeable membranes is yet to develop fully and every day will find applications in industry based on the concept.
Principles Considering the above, "the osmotic phenomenon is the basis of the feeding cell, it is clear that any study must be closely linked to scientific development and therefore the different disciplines of science as "born" as different disciplines during the nineteenth century (biology, chemistry, physical chemistry, thermodynamics, etc..).
this paper is not proper support for a thorough examination of the birth of the different sciences, but it seems logical that medicine and biology anticipated as the man tries to solve the problems that create the diseases and advancing science, especially through the observation of natural phenomena and development.
Between 1800 and 1900 developed biology and medicine with Bichat (1771-1802) as a precursor, in 1844 and had established a new science of histology.
During this period there is a strong scientific and industrial development and therefore all researchers seeking scientific support for the phenomena they are observing, looking for explanations in chemistry and its processes to model the biological behavior. Recall that
Louis Pasteur (1822-1895) was the "father" of the experimental method in medicine, and we must not forget that there was no doctor, but a biologist, and yet the study of germs and action about life is based on its principles and studies, we can say put the chemistry in the service of medicine.
All this description of the nineteenth century is important to us from the point of view that mid-century to discover the osmotic phenomenon and its relationship with cellular processes.
Yes it is true that the first industrial membrane and the first reverse osmosis equipment was built in the U.S., as we shall see, but it is also true that all the studies and developments in chemistry, physics, medicine, etc. during the nineteenth century took place in old Europe, always in the shadow of industrial and technological development of industry Private.
not yet been given the true significance nor has magnified enough discovery Mendeleev (1834-1907). Yes, we all studied the Periodic Table of the Elements, he published, but what little was said is that changed scientific thinking at the time, which obviously was wrong, and that was not easy because it required a complete overhaul of knowledge bases on the organization of matter, ie, discovered the history of atomic physics and quantum chemistry would take almost 100 years to develop.
mid-nineteenth century continued progress compartmentalization of science, there are disciplines such as physicochemical and thermochemical reactions: catalysis, electrolysis, studies of the atom and especially important for the study of physics osmosis solutions.
We must say that most theories are born of the attempt to understand the behavior of the atom, and as the easiest to handle on their quick reaction to changes in temperature were the gases, most experiments were carried out with gas.
Thomas Graham (1805-1869) was the father of colloid chemistry while Raoult (1830-1901) with The Theory of Solutions which were laid the foundations of physical chemistry as a scientific discipline. But remember that many scientists studied simultaneously within the field of physiology, cellular transport phenomena in plants and animals, etc. Therefore, the two disciplines are intertwined: the study of gases and their behavior in the solutions with the cell studies and exchanges. It is then discovered the osmotic phenomenon.
We have said that osmosis is based on the Theory of Solutions and although Graham was the father of the studies and experiments on the flow of diffusion of a gas through a porous plug, etc.. (The flow of gas diffusion through a porous plug is inversely proportional to the square root of the densities of the gases used), we see that concept is already appearing "passing" substance "through a semi -permeable, without external energy consumption. " But it was
Fick (1829-1901) who is considering Graham's experiments on a quantitative basis and similarities between the studies on electrical and thermal conductivity, formally established the mathematics of diffusion. Basically, "the presence of a diffusion flux is due to a difference in concentration. "
There was at that time quite a shock when Fick published his study and its results, caused a "revolution" on many scientific concepts that had until then and we all know that the "stagnation" is inherent in certain societies.
The main problem is that both Graham and Fick explained the phenomenon of the dissemination of descriptive and quantitative but were unable to clarify "why", similar to what we said at the beginning with reverse osmosis.
In the second half of the nineteenth century was Maxwell (1831-1879), who gave support to the "why" with his theories on molecular motions , relative velocities, agitation, etc. . all at the molecular level.
In all this we see we are slowly coming to the osmotic phenomenon is that we are concerned in this paper, but as usual in the history of science, observation, experiment, well ahead of the explanation phenomenon itself and its physical and mathematical modeling.
say this because the discovery of osmosis is prior to the dissemination and the theory of solutions that are the basis for the explanation of it. In 1748
Nollet (1700-1770), professor of experimental physics at the University of Navarra , experimented with a "membrane" made from the wall of the bladder of an animal , putting aside alcohol and water to the other and found that water flowed from side to side to mix with alcohol but the reverse NEVER BE PRODUCING.
is, Nollet in the eighteenth century and discovered the existence of "semi-permeable membranes " and defined the osmotic process and allowing the passage of one of the components of a solution but not the others.
solvent called substance which is capable of crossing the membrane and solute which can not flow through it.
But it was not able to explain why this phenomenon occurred, it was impossible to explain it with the knowledge of the time needed will be 100 years to explain a little better and lay the foundation, but as we have said there is still no reliable explanation and a mathematical model that supports the osmotic phenomenon, as we shall see.
was a medical researcher Dutrochet Henri (1776-1847), who made the discovery of the osmotic phenomenon through semi-permeable membranes , and did so within its target Home: demonstrate that the fundamental laws of chemistry and physical and therefore mathematics were able to explain the basic processes of life.
Therefore we can set as the date of discovery of the osmotic phenomenon we know as 1828, the date on which public Dutrochet "that if you have two solutions with the same solute, which can not cross the membrane, on each side of a semi permeable membrane, the osmotic flow always occurred less concentrated solution to the most concentrated and the solvent flowing course which caused pressure on the membrane which he called osmotic pressure "was born
the reverse osmosis technology, but really did not know" why "the solvent acted as he did.
Dutrochet insist that came to these conclusions and findings trying to explain the processes taking place in the living cell is surrounded by a semi permeable membrane and water absorbed by osmosis .
It took 50 years to quantitatively measure the osmotic pressure and was Pfeffer (1845-1920) in 1877 who did it. Was a botanist and needed to do in studies performed on photosynthesis.
main thing studies Pfeffer and we want to emphasize is that biological membranes but did not use artificial bases were consolidated for reverse osmosis as we know it.
But until Van't Hoff (1852-1911) compared with the osmotic pressure that was on a gas, the phenomenon of osmosis never left the hands of physiologists to go to the physical and chemical. He and Gibbs (1839-1903) consolidated the relationship between osmosis and the theory of solutions, and comparison between the kinetics of osmosis and gas was, as least original and attracted the interest of the scientific community.
But ideas were wrong and were abandoned in the early twentieth century, the osmotic pressure definitely is not the result of collision of molecules against the wall formed by the membrane begins to handle the concept of "chemical energy solution ", is definitely established as a science of physical chemistry and chemical thermodynamics theories explain the phenomenon osmotic advance, understanding osmotic pressure as a difference of chemical energy solutions.
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