The phenomenon of Brownian motion was explained by Robert Brown who was a British Surgeon, and Botanist. He described Brownian motion in the 19th century and the name of this phenomenon is referred to as his name. It is a simple and stochastic process and can be mathematically modeled for the characterization of movements of nanoparticles and nanomaterials in the immersion fluids. This article is focused to explain the Brownian motion of suspended solids and supporting theories.
Brown noticed various observations under his microscopic studies for particulate matter like pollen grains. He reported that these materials appear in the constant agitation states. Other than this, an oscillatory and vivid motion was also observed when this particulate matter was suspended in water or solution.
What Causes Brownian Motion
Brownian motion happens due to thermal energies and can be monitored by the kinetic molecular theories of heat. This theory is considered because its properties are applicable to the diffusion-related phenomenon. There is a work of many scientists behind the present-day Brownian motion concept and we will elaborate on the major studies in this article.
Brownian Motion of Suspended Solids and Supporting Theories
Brownian Motion and Work of Jan Inhgenhousz
The present-day Brownian motion phenomenon was first recorded by Dutch botanist and physiologist Jan Inhgenhousz. This scientist is well known for his discoveries to show the importance of light for plant respiration. Other than this he also observed the irregular movements by the carbon dust motes in ethanol. The second observation was noted in 1784.
Brownian Motion and Work of Adolphe Brongniart
Similar observations were also made by Adolphe Brongniart in 1827 but generally, the phenomenon of Brownian motion can be most accredited to Robert Brown (Scottish-born botanist). Even though his work related to the primrose pollen experiment was not published even after thirty years of his death. Firstly, he tried to attribute the pollen granules movement in the water as pollens were alive. He repeated the experiment by using smaller shards of commonly used window glass and then with the quartz crystals. Based on the results he concluded that these results were not dependent on vitality. He got puzzled due to the results and then was never able to explain the process again.
Brownian Motion and Work of Louis Bachelier
Louis Bachelier was the first person to make an actual theory about Brownian motion. He was a French Mathematician and proposed a model to explain Brownian motion in 1990. This model and explanation were a part of his Ph.D. degree and thesis.
Brownian Motion and Work of Albert Einstein
Another scientist Albert Einstein presented his Ph.D. thesis about osmotic pressure and discussed a detailed statistic theory about the behaviors of liquids according to the existence of molecules. Later on, he applied the liquid kinetic-molecular theory of heat for an explanation of the phenomenon as observed by Brown. He further suggested that the movement of suspended particles in the liquids can be explained due to random thermal agitations of molecules present in the surroundings.
Browbnian Motion and Work of Felix Ehrenhaft and Theodor Svedberg
The work of Felix Ehrenhaft and Theodor Svedberg supported the Brownian motion observations of silver particles and colloids in the air. The findings of this study also supported the results of Einstein. The predictions of Einstein were also tested by the experimental work of Jean Perrin. He was a French physicist and was awarded a noble prize in Physics. He won this prize in 1926 and his work was solely related to Brownian motion. The results of empirical verification about Einstein’s Brownian motion model were published. Now there is wide accreditation of his results. But this accreditation was also subjected to dispute for a long century due to Jhon’s Dalton theory about the existence of atoms.