Chapter 1
How Old is Nanotechnology?

Mrinal Chakre and Madhuri Sharon

Walchand College of Arts and Science, Solapur University, Solapur, Maharashtra, India

I want to know why the universe exists, why there is something greater than nothing.
Stephen Hawking

Preamble

When we sat down to write this chapter, the first thing that came to mind was whether there are nanoparticles existing in nature which are not man-made or fabricated. Both biotic and abiotic natural nanoparticles came to mind. The next question was, "Since when?" Nanoparticles by definition are particles of any shape with an equivalent diameter of 1-100 nm, i.e., specifically those particles that are intermediate in size between bulk materials and atomic/molecular structures or quantum dots. These nano-size particles exhibit unique physical and chemical properties due to their distinctive novel properties related to a high surface area to volume ratio and/or quantum effects.

A quick glance at various scales of measurement (Table 1.1) gives an idea of how small a nanometer is. A nanometer (nm) is one thousand-millionth of a meter. For comparison, a red blood cell is approximately 7,000 nm wide and a water molecule is almost 0.3 nm across. People are interested in the nanoscale (which is defined to be from 100 nm down to the size of atoms (approximately 0.2 nm) because it is at this scale that the properties of materials can be very different from those at a larger scale. Nanoscience is defined as the study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales, where properties differ significantly from those at a larger scale; and nanotechnologies as the design, characterization, production and application of structures, devices and systems by controlling shape and size at the nm scale.

Table 1.1 Scales of Measurement.

Let us look at some of the known naturally occurring nanoparticles. Depending on the origin, a distinction is made between three types of nano-size particles: (i) natural, (ii) incidental and (iii) engineered. Natural nanoparticles from volcanic dust, lunar dust, mineral composites, etc., have existed since the beginning of the Earth. Some such nanoparticles still occur in the environment and are termed incidental nanoparticles, also defined as waste or anthropogenic particles, which take place as the result of man-made industrial processes such as diesel exhaust, coal combustion, welding fumes, etc.

1.1 Introduction

Our present awareness of nanotechnology (materials of a size between 1-100 nm, having novel properties that are not found in their bulk counterpart) started in the 1980s, caused by the convergence of experimental advances such as the invention of the scanning tunneling microscope in 1981 and the discovery of fullerenes in 1985, with the elucidation of a conceptual framework for the goals of nanotechnology. Nanotechnology became popularized as a result of the Nobel Prize being awarded for many nanoparticle discoveries; i.e., Nobel Prizes were awarded to Heinrich Rohrer in 1986 for the invention of the scanning tunneling microscope, to Kroto et al., in 1985 for the discovery of fullerene, and to Geim and Novoselov in 2010 for graphene. The ideas and concepts behind nanoscience and nanotechnology started with a talk entitled "There's Plenty of Room at the Bottom" by physicist Richard Feynman at an American Physical Society meeting at the California Institute of Technology (Caltech) on December 29, 1959, long before the term nanotechnology was coined in 1974 by Taniguchi.

Our concern in this chapter is to address the questions of "How old is nanotechnology?" and "Are there naturally occurring nanoparticles; if so, since when?" To know the existence of nanoparticles on Earth, which is part of this universe, we realize that their origin plays a great role in the existence of any matter.

There was a time when scientists thought Earth was at the center of the universe. As late as the 1920s, we did not realize that our galaxy was just one of many in a vast universe. Only later did we recognize that the other galaxies were running away from us-in every direction-at ever greater speeds. Our universe is both ancient and vast, and expanding out farther and faster every day. This accelerating universe, the dark energy that seems to be behind it and other puzzles, like the exact nature of the Big Bang and the early evolution of the universe, are among the great puzzles of cosmology.

About 11 to 15 billion years ago all of the matter and energy in the universe was concentrated into an area the size of an atom. At that moment, matter, energy, space and time did not exist. Then suddenly, the universe began to expand at an incredible rate and matter, energy, space and time came into being (the Big Bang). As the universe expanded, matter began to coalesce into gas clouds, and then stars and planets. Our solar system formed about 5 billion years ago when the universe was about 65% of its present size. Today, the universe continues to expand along with the existence of nanoparticles.

Though the chemical properties of a bulk material depend on its molecular structure, when they assemble at the nano level they exhibit other unique and novel physicochemical properties. That may be why nature decided to naturally synthesize particles at the nano level to contribute to the evolution of our Earth or perhaps other planets also.

Prehistoric events date back to the time before the invention of writing-roughly 5,000 years ago. Without access to written records, scientists investigating the lives of prehistoric people face special challenges. A lot of knowledge has been lost due to man-made activities like wars, as well as natural calamities such as earthquakes, tsunamis, floods, volcanic eruptions and meteor showers, which have caused tremendous adverse effects.

What are natural nanomaterials? As the name suggests, natural nanoparticles are synthesized by nature without the interference of man.

At a very vast level of understanding of naturally occurring nanoparticles, Sharma et al., [1] have considered five major points, namely, (i) the presence of naturally occurring nanoparticles in the atmosphere, hydrosphere, lithosphere and biosphere, (ii) the presence of naturally occurring organic matter and its role in the formation of metal nanoparticles like silver and gold, (iii) another important matter that they have considered is how the reaction between reactive oxygen species and natural organic matter at elevated temperature and/or exposure to light supports the formation of metal nanoparticles, (iv) how the properties and role of water especially related to the pH, redox conditions, ions/ionic strength and concentrations of natural organic matter determine the growth and stability of NPs in the aquatic environment, and finally (v) the impact of natural conjugation of organic matter with natural metal nanoparticles on toxicity, which may be less than that of the engineered nanoparticles that are surface-coated by polymers and/or surfactants.

These considerations are based on the fact that there are naturally occurring nanoparticles that came into existence even before the formation of Earth. In nature, nanoparticles are naturally formed in all spheres of the Earth (atmosphere, hydrosphere, lithosphere and biosphere), either by chemical, photochemical, mechanical, thermal, and biological processes separately or in combination; and/or also by extraterrestrial inputs. Typical naturally occurring nanoparticles include (a) metals such as Ag, Au and Fe, (b) metal oxides, e.g., Al2O3, Fe2O3, MnO2 and SiO2, (c) metal sulfides like FeS2 and ZnS, etc.

1.2 Nano-Geosystem for Abiotic Nanoparticles Formation

In the first stage of chemical evolution on earth, molecules formed in the primitive environment were simple organic substances such as amino acids. This concept was first proposed in 1936 by Oparin [2]. He considered hydrogen, ammonia, water vapor and methane to be components...