Key Properties and Real-World Applications of Plasma
In physics, plasma is an electrically conducting medium, where there are roughly equal numbers of both positively and negatively charged particles, which are produced when the atoms in a gas become ionized. Sometimes, it is referred to as the fourth state of matter, which is distinct from the solid, liquid, and gaseous states.
About Plasma
Usually, the negative charge can be carried by the electrons, where each has one unit of negative charge. Typically, the positive charge is carried by molecules or atoms that are missing similar electrons. In some of the rare but interesting cases, electrons missing from one type of molecule or atom become attached to the other component by resulting in a plasma containing positive and negative ions.
When small, the most intense case of this sort takes place, but in a condition known as a dusty plasma, the macroscopic dust particles are charged. The plasma state's uniqueness is because of the importance of magnetic and electric forces that act on the plasma in addition to the kind of forces as gravity that affect all forms of matter. Since all these electromagnetic forces act at a larger distance, the plasma will also act collectively much similar to a fluid even when the seldom particles collide with one another.
Volume of Plasma
The volume of blood plasma can be either expanded or drained to the extravascular fluid when there are changes in starling forces across capillary walls. For instance, when blood pressure drops in a circulatory shock, the starling forces drive fluid into the interstitium by causing third spacing.
Standing for a prolonged period will cause a transcapillary hydrostatic pressure increase. Resultantly, approximately 12% of the blood plasma volume will cross into the extravascular compartment. And this contributes to an increase in overall serum protein, hematocrit, blood viscosity, and changes in coagulation factors as a result of this accumulation, inducing orthostatic hypercoagulability.
Properties of Plasma
Albumins are the most common plasma proteins and are also responsible for maintaining the blood's osmotic pressure. The consistency of blood would be closer to that of water without albumins. The blood’s increased viscosity prevents the fluid from entering the bloodstream from outside of the capillaries. Globulins are given as the second most common type of protein present in the blood plasma. The important globulins are immunoglobulins, which are most important for the transport of hormones, the immune system, and other compounds around the body.
Fibrinogen proteins will make up most of the remaining proteins in the blood. Fibrinogens are also responsible for clotting blood to help prevent blood loss.
Colour
In general, plasma is yellow because of carotenoids, bilirubin, transferrin, and haemoglobin. Coming to the abnormal cases, plasma can also have varying shades of green, brown, or orange. The green colour can be because of sulfhemoglobin or ceruloplasmin. The latter can form because of the medicines, which are able to produce sulfonamides once ingested. Reddish or dark brown colour can appear because of hemolysis, where methemoglobin is released from broken blood cells. Normally, plasma is relatively transparent, but at times, it can be opaque. Typically, opaqueness is because of the elevated content of lipids such as triglycerides and cholesterol.
Origin of Plasmapheresis
A scientist from Spain, named Dr. José Antonio Grifols Lucas in 1940, founded Laboratorios Grifols. Dr. Grifols pioneered the first-of-its-kind technique, which is referred to as plasmapheresis, where a red-blood-cell would be returned to the body of the donor almost instantly after the blood plasma separation.
Formation of Plasma
Besides solid-state plasmas, like those in metallic crystals, plasmas don’t usually take place naturally at the surface of the Earth. For the experiments, which are held in laboratory and technological applications, plasmas, hence, must be produced artificially. Because the atoms like alkalies as sodium, caesium, potassium possess low ionization energies, and plasmas can be produced from these by the direct application of heat at up to 3,000 K temperature. However, in many gases, before any significant ionization degree is achieved, the neighbourhood temperatures of 10,000 K are required.
A convenient unit for measuring the temperature in the plasma study is the electron volt (eV), the energy gained by an electron in the vacuum when it is accelerated across 1 volt of electric potential. The temperature (W) can be measured in electron volts, which is given as follows:
W = T/12,000
Where T is expressed in kelvins.
The required temperatures for the self-ionization hence range from 2.5 - 8 electron volts since such values are typical of the energy required to remove one electron from a molecule or atom.
Plasma Waves
The waves, which are most familiar to people, are the buoyancy waves, which propagate on the lakes and ocean surfaces and break onto the beaches of the world. Equally familiar, although not essentially recognized as waves, are the disturbances caused in the atmosphere that create, which is called weather.
FAQs on Plasma State of Matter Explained
1. What is plasma, often called the fourth state of matter?
Plasma is a distinct state of matter, different from solid, liquid, and gas. It is an ionised gas, which means it consists of a mix of free-moving electrons and positively charged ions, along with some neutral atoms. Unlike a regular gas, plasma is electrically conductive and is strongly influenced by magnetic and electric fields.
2. How is the plasma state of matter formed from a gas?
Plasma is formed when a significant amount of energy is supplied to a gas. This energy, typically in the form of extreme heat or a strong electric field, causes the atoms and molecules in the gas to lose their electrons. This process, known as ionisation, creates a mixture of free electrons and ions, transforming the gas into plasma.
3. What are the key properties that distinguish plasma from a neutral gas?
The primary properties that make plasma unique compared to gas are:
- Electrical Conductivity: Due to the presence of free-moving charged particles (electrons and ions), plasma can conduct electricity.
- Interaction with Magnetic Fields: Plasma can be confined, shaped, and accelerated by magnetic fields.
- Emission of Light: As electrons fall to lower energy levels, they release energy as light, which is why plasmas like those in stars and neon signs glow.
- Collective Behaviour: The particles in plasma interact over long distances through electromagnetic forces, causing it to behave as a whole entity rather than as a collection of individual particles.
4. Where can we find examples of plasma in the universe and on Earth?
Plasma is the most abundant state of matter in the universe. Examples include:
- In the Universe: Stars (including our Sun), nebulae, the solar wind, and the interstellar medium are all made of plasma.
- On Earth: Natural examples include lightning and the aurora borealis. Artificial examples are found in plasma TVs, neon signs, fluorescent lights, and in industrial applications like semiconductor manufacturing and fusion energy research.
5. Why is plasma considered a distinct state of matter and not just an 'ionised gas'?
While plasma is an ionised gas, it is classified as a distinct state of matter because of its collective behaviour. The presence of a significant number of free charge carriers leads to long-range electromagnetic interactions among its particles. This causes plasma to exhibit properties—like generating its own magnetic fields and forming structures like filaments and beams—that are fundamentally different from the random, collision-dominated behaviour of a neutral gas.
6. How does plasma's composition allow it to conduct electricity so effectively?
Plasma's ability to conduct electricity comes from its fundamental composition: a soup of freely moving charged particles. It contains negative electrons and positive ions that are not bound to atoms. When an electric field is applied, these charged particles are free to move and create an electric current. The electrons, being much lighter, move quickly and carry most of the current, making plasma an excellent electrical conductor.
7. Who is credited with discovering the plasma state, and why was it given that name?
The plasma state was first identified by English physicist Sir William Crookes in 1879 while studying cathode rays in a discharge tube. However, the term 'plasma' was coined much later, in 1928, by American chemist and physicist Irving Langmuir. He used the name because the ionised gas's ability to carry various particles, like electrons and ions, reminded him of how blood plasma carries red and white blood cells.
8. What is the difference between 'hot plasma' and 'cold plasma'?
The difference lies in the temperature of the particles. Hot plasma, or fully ionised plasma, is found in stars and fusion reactors where the temperature is so high (millions of degrees Celsius) that both electrons and ions are in thermal equilibrium. In contrast, cold plasma, or partially ionised plasma, is found in devices like fluorescent lamps and for medical sterilisation. In cold plasma, the electrons are very energetic (hot), while the heavier ions and neutral atoms remain at a much lower temperature, sometimes even close to room temperature.
