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Researchers at the Raman Research Institute (RRI), Bengaluru — an autonomous institute of the Department of Science and Technology — have shown that sudden temperature shocks can briefly make a jammed, glass-like system flow, wiping out the memory imprints stored in it.
Working with suspensions of microgel particles, the team found that the path the suspension took to reach 20 degrees Celsius on heating was not the mirror image of the path on cooling; raising the temperature ramp rate sharply pushed the jammed system into a temporary liquid state, erasing that path memory and reducing the asymmetry.
The finding matters for targeted drug delivery: the microgels used are loaded with a drug while swollen at low temperature and collapse above about 34 degrees Celsius, squeezing the medicine out at the target site, so controlling their structural recovery makes the release more predictable.
Materials such as glass behave mechanically like solids — they hold their shape and resist deformation — but their internal arrangement of particles is disordered, like that of a liquid, with none of the repeating long-range order of a crystal. Such materials are called amorphous. A related idea is jamming: when soft particles are packed densely enough, they lock against one another and the whole assembly becomes rigid, even though nothing has crystallised. A jammed or glassy system is trapped away from its lowest-energy arrangement, and the slow process by which it tries to flow towards that minimum-energy configuration is called structural recovery. Because the system is stuck, it also remembers what was done to it: heat it and cool it back to the same temperature and it does not retrace the same path, so its state depends on its history. The RRI work shows that a sharp thermal shock can rearrange the particles enough to unjam the system briefly and wipe that history clean.
Simple Analogy: Think of a crowd packed into a doorway. Everyone is standing still and the crowd as a whole is rigid — jammed — even though each person would rather move. A sudden jolt makes the crowd shuffle and flow for a moment, and when it settles nobody is standing where they were before: the arrangement the crowd had built up is forgotten.
Founded in 1948 by Nobel laureate Sir C.V. Raman with private funds, to continue his research after he left the Indian Institute of Science. It was restructured in 1972 as an aided autonomous research institute funded by the Department of Science and Technology. Its main research areas today are astronomy and astrophysics, light and matter physics, soft condensed matter, and theoretical physics — this study belongs to the soft condensed matter group.
The nodal department under the Ministry of Science & Technology for promoting new areas of science and technology and coordinating S&T activities. It funds a set of autonomous research institutes, of which RRI is one; others include the Indian Institute of Astrophysics (Bengaluru), the Jawaharlal Nehru Centre for Advanced Scientific Research (Bengaluru) and the Aryabhatta Research Institute of Observational Sciences (Nainital).
A microgel suspension is a colloidal system — particles dispersed in a liquid medium. Soft matter physics covers colloids, gels, foams, emulsions and polymers, all of which sit between the classical solid and liquid states.
Glass is the standard example of an amorphous solid, contrasted in every basic chemistry syllabus with crystalline solids that have long-range order and sharp melting points.
Stimulus-responsive carriers — responding to temperature, pH or light — are the wider field this work feeds, alongside nanoparticle and liposome-based delivery systems.
RRI carries the name of the physicist whose discovery of the Raman effect, announced on 28 February 1928, is commemorated as National Science Day and won him the Nobel Prize in Physics in 1930.
GS Paper 3 > Science and Technology > Developments in Materials Science and Indian Research Institutions
General Awareness > Science and Scientific Institutions
With reference to the use of nanotechnology in health sector, which of the following statements is/are correct? 1. Targeted drug delivery is made possible by nanotechnology. 2. Nanotechnology can largely contribute to gene therapy. Which of the statements given above is/are correct?
Answer: Both 1 and 2
Indian research institutions and their parent departments are asked regularly; the underlying physics of amorphous solids is standard basic-science material.
A solid whose particles are arranged without the long-range periodic order of a crystal — glass being the standard example — so that it is structurally liquid-like but mechanically rigid.
The transition in which densely packed particles lock against each other and the assembly becomes rigid, without any crystallisation taking place.
The process by which a jammed or glassy system slowly rearranges towards its minimum-energy configuration.
A soft, highly swellable polymer particle that can absorb many times its weight in water and change size with temperature; used in absorbent products, coatings and drug delivery.