High Performance Biodegradable Polymers
Biobased and biodegradable thermoplastics have become competitive commodity materials to petroleum-based thermoplastics over the past decade. Among them, polylactide being a commodity plastic used to make fibres and packaging films, is used in biomedical implants, surgical sutures, and bone fixation devices. One of the major drawbacks of polylactide is its poor crystallization rate, toughness and low crystallinity.
Our interests in this area are:
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Understanding the structure-formation mechanism in biodegradable polymers and their impact on material properties
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The fundamental understanding of stereocomplex formation and the molecular recognition in helical polymers
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Development of biodegradable nanocomposites and biopolymer aerogels for multifunctional applications
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Transparent packaging films by retaining the polymer crystallinity
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Development of bio-based polymers with aggregation-induced emission (AIE) and aggregation caused quenching (ACQ) characteristics with prospected applications in bio-imaging and medical/pharmaceutical fields
ACS Maco Letters, 2022,11, 1272-1277
Macromolecules, 2017, 50, 5261-5270
Macromolecules, 2016, 49, 224-233
Polymer Chemistry, 2022, 13, 838-849
Soft Matter, 2018, 14, 1492-1498
Soft Matter, 2023, 19, 6671-6682
CrystEngComm, 2021, 23, 2122-2132
European Polymer Journal, 2024, 203, 112676
Polymer, 2022, 241, 124530
Polymer, 2022, 240, 12449
Self-assembly of Block Copolymers
Our research focuses on nanostructured polymers with the aim of opening up new areas of applications and clarifying the relevant science in the field. For many practical applications of these nanostructures, it is necessary to have knowledge on the conditions that lead to the formation of a certain structure in the nanometer range.
We are interested in
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Block copolymer based nanoscopic structures (both in bulk and in thin films) formed by self-assembly
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Tuning the nanostructure morphologies of semicrystalline block copolymers by controlling the interplay between crystallization and microphase separation
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Understanding the factors that control the orientation of block copolymer microdomains and the mechanism of orientational changes of microdomains formed in block copolymer thin films
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Multi-component hierarchical self-assembly of donor and acceptor molecules within the block copolymer microdomains in the solid state through the non-covalent interactions
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Integration of polymerizable small molecules within the block copolymer templates for the generation of supramolecular photopolymerizable materials
Macromolecules,2019, 52 (7), 2889-2899
Macromolecules, 2015, 48 (15), 5367-5377
ACS Appl. Mater. Interfaces,2015, 7, 12559-12569
Polym. Chem, 2019, 10 (23), 3154-3162
Soft Matter, 2020, 16 (31), 7312-7322
Polymer, 2016, 105, 422-430
Mater. Today Commun., 2020, 24, 101147
Bull. Mater. Sci., 2020, 43 (1), 1-9
High Performance Polymer Nanocomposites
Polymer-based nanocomposites filled with nanosized stiff particles have evolved and attracted great interest from both industry and academia during the last two decades. The performance of polymer nanocomposites strongly depends on the degree of dispersion and aspect ratio of nanofillers in the polymer matrices. Our group mainly focuses on nanofillers like synthetic clays, i.e., layered double hydroxides (LDH), boron nitride nanosheets (BNNSs), polyhedral oligomeric silsesquioxane (POSS), zirconium phosphate, etc. We cover the complete range of synthesis-structure-property towards the development of multifunctional polymer nanocomposites.
Our major research themes in this area are as follows
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Development of multifunctional fillers for semicrystalline polymers
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Development of sustainable flame retardant fillers for biodegradable polymers
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Multifunctional polymer nanocomposites with enhanced thermal, mechanical, optical and flame retardant properties
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Preparation of two-dimensional quantum dots and their nanocomposites
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Tuning the dielectric, EMI shielding and piezoelectric properties of polymers (in collaboration with Dr. K.P. Surendran and Dr. Achu Chandran)
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Anticorrosive coatings for aluminum alloys (in collaboration with Dr. T.P.D. Rajan)
ACS Sustainable Chem. Eng.,2020, 8 (4), 1868-1878
ACS Macro Letters,2022, 11 (11), 1272-1277
ACS Appl. Mater. Interfaces,2015, 7 (34), 19474-19483
ACS Appl. Mater. Interfaces,2015, 7 (23), 12399-12410
ACS Appl. Nano Mater.,2018, 1 (1), 111-121
J. Phys. Chem. B,2019, 123 (40), 8599-8609
J. Phys. Chem. B,2018, 122 (24), 6442-6451
ACS omega,2017, 2 (1), 20-31
ACS Omega,2016, 1, 1220-1228
Langmuir,2019, 35 (13), 4672-4681
Applied Clay Science, 2021, 211, 106199
Polym. Int.,2016, 65 (3), 299-307
J. Macromol. Sci. A, 2022, 59(4), 257-270
Multifunctional Gels and Aerogels
Polymer gels are typically formed through a three-dimensional network based on physical aggregation such as polymer crystallization, complex formation, phase separation or multiple noncovalent interactions instead of covalent bonds. In certain cases, the solvent used for the physical gelation of polymers can form crystalline complexes (cocrystals, where the solvent molecules are accommodated within the crystal lattice of the polymer. Our group mainly focuses on gel formation using such systems. We are using an environmentally benign freeze-drying technique for the extraction of solvents from the gels and the resultant aerogels have nanopores within the crystal lattice (crystalline nanoporous aerogels).
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Our group’s interests in this area are:
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Understanding the gelation behavior of semicrystalline polymers and their blends using a solvent that is capable of forming crystalline complexes (cocrystals) with polymers
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Supramolecular gel formation using helical polymers and understanding their hierarchical structure formation
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Preparation and multifunctional applications of polymer aerogels with a three-level hierarchical porosity (identical microporosity (<2 nm) inside the crystalline cavities along with disordered mesopores (2-50 nm) and macropores (>50 nm))
ACS Appl. Mater. Interfaces,2023, 15(42), 49567-49582
Macromolecules, 2021, 54 (22), 10605-10615
ACS Appl. Polym. Mater.,2023 5, 2, 1556–1564
J. Mater. Chem. C, 2018, 6 (2), 360-368
Polymer Chemistry, 2022, 13, 838-849
ACS Appl. Polym. Mater.,2022, 4, 7, 5113–5124
Polymer, 2022, 241, 124530
Polymer Crystal Engineering
Polymers offer a great potential to meet the requirements from the market better than other materials since their physical and chemical properties can be easily tailored by their structures at different length scales. The chemical structure at the molecular scale and the morphology at multiple length scales (see Figure) of the polymers determine the mechanical and physical properties of the polymers.
Our group mainly focuses on the following aspects.
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Control of structure and morphology of semicrystalline polymers, and thereby the physical and mechanical properties, by understanding the crystallization behavior of polymers under different environments and conditions
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Understanding the intimate correlation between the chain conformation, crystal structure and the morphological change of stacked lamellae during the phase transition in various semicrystalline polymers
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Polymer co-crystals and polymorphism
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Mesophase-mediated crystallization of polymers
Macromolecules, 2016, 49, 224-233
Soft Matter, 2018, 14, 1492-1498
Soft Matter, 2022, 18, 2722-2725
Polymer, 2022, 240, 124495
Polymer, 2015, 56, 581-589
Polymer, 2013, 54 (24), 6617-6627
Macromol. Symp., 2016, 359 (1), 104-110
SPE Polymers, 2022, 4, 1-13
Natural Fibres and Composites
Among various natural fibres produced in India, coconut fibre, commonly known as coir, has the shortest renewable time and stands next to jute fibre in production. India accounts for more than two-thirds of the world’s production of coir and coir products. Kerala is the home of the Indian coir industry, particularly white fibre, accounting for 61 % of coconut production and over 85 % of coir products. Coir has been used for creating environment-friendly products such as mattresses and geotextiles, construction of roads, horticulture, buildings, etc. Recent advances in the field of composite technology paved the development of new coir-based products for the commercial exploitation and diversification of their applications. Over the past several years, CSIR-NIIST has been working in the area of coir fibre composites that acquired unique knowledge and expertise and developed product targeted processes.
CSIR-NIIST focuses on the development of process know-how in the following areas.
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Process development for surface modification of coir fibers using plasma treatment
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Process development for enhancing the longevity of coir geotextiles (coir bhoovastra)
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Biodegradable mulching mats using bio-based polymer and coir composites
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Development of coir based cutleries and binderless boards
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Production of polymer/coir composites for furniture, acoustic and electrical insulation applications
Two-Dimensional Small-Angle /Wide-Angle X-ray Scattering (SAXS/WAXS)
Two-dimensional small-angle /wide-angle X-ray scattering (SAXS/WAXS) with variable temperature attachment is installed at CSIR-NIIST in 2013. It covers an angular range corresponding to 0.3 to 50 nm lattice dimension, with an angular resolution of 0.01° (It can be used for both SAXS/WAXS). A large area image plate detector allows us to increase the amount of scattered X-rays to obtain the complete Debye diffraction rings. It is a good addition for a laboratory-like CSIR-NIIST, where the research activities are mainly focused on the areas of nanomaterials, liquid crystalline materials, polymers, biological materials and supramolecular materials.
This facility is open for the industry partnership to understand the structure-property relations of their materials in two complementary length scales. Interested may visit the CSIR-NIIIST site for more details.
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