Aparna Beena Unni

Dr. Aparna Beena Unni

Institute of Physics, Uniwersytet Slaski w Katowicach, Katowice, Poland
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 June 2024 in Polymers
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Journal Article
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AUAparna Beena Unni
Aparna Beena Unni
TJTomy Muringayil Joseph
Tomy Muringayil Joseph
Polymer sustainability is a pressing concern in today’s world driven by the increasing demand for environmentally friendly materials. This review paper provides a comprehensive overview of eco-friendly approaches towards enhancing the sustainability of polymers. It synthesized recent research and developments in various areas such as green polymer synthesis methods, biodegradable polymers, recycling technologies, and emerging sustainable alternatives. The environmental impact of traditional polymer production processes and the importance of adopting greener alternatives were critically examined. The review delved into the advancements in polymer recycling technologies like mechanical, chemical, and biological processes aimed at minimizing plastic waste and promoting a circular economy. The innovative approaches such as upcycling, hybrid methods etc., which offer promising solutions for addressing plastic pollution and achieving long-term sustainability goals were also analyzed. Finally, the paper discussed the challenges and future prospects of eco-friendly approaches for polymer sustainability, emphasizing the need for researchers and concerted efforts from scientists across industries and academia to drive meaningful change towards a more sustainable future.

7 March 2023 in C
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Journal Article
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TJTomy Muringayil Joseph
Tomy Muringayil Joseph
AUAparna Beena Unni
Aparna Beena Unni
JKJoshy KS
Joshy KS
DMDEBARSHI KAR MAHAPATRA
DEBARSHI KAR MAHAPATRA
Józef Tadeusz HaponiukJózef Tadeusz Haponiuk
Józef Tadeusz Haponiuk
STSabu Thomas
Sabu Thomas
Due to the rising worldwide demand for green chemicals, the bio-based polymer market is anticipated to expand substantially in the future. The synthesis of functional polymers has been a burgeoning area of research for decades. The primary driving force behind the development of bio-based polymers has been their compostability and biodegradability, which are critical given the public concern about waste. Significant advancements in the method for refining biomass raw materials towards the creation of bio-based construction materials and products are driving this rise. Bio-based polymers with this chemical structure are more flexible and adaptive, which allows them to attain their intended characteristics and functionalities. In commercial applications and healthcare and biotechnology, where completely manufactured, naturally occurring biomolecules are utilized and such polymers have the greatest impact. At the same time, limitations in polymer architectural control, biostability, and structural dynamics hinder the creation of biocompatible and functionally varied polymers. From this standpoint, the importance of functional biosynthetic polymers in the future years is highlighted, as well as new methods for addressing the aforementioned challenges. The article comprehensively highlighted the current strategies, market dynamics, and research trends of emerging Bio-Based Polymers. In addition, the most recent scientific breakthroughs in bio-based polymers are discussed.

28 September 2022 in The Journal of Physical Chemistry B
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Journal Article
Open access
AUAparna Beena Unni
Aparna Beena Unni
RWRoksana Winkler
Roksana Winkler
DDDaniel Marques Duarte
Daniel Marques Duarte
CKChat Katarzyna
Chat Katarzyna
KAKarolina Adrjanowicz
Karolina Adrjanowicz
The substrate roughness is a very important parameter that can influence the properties of supported thin films. In this work, we investigate the effect of surface roughness on the properties of a vapor-deposited glass (celecoxib, CXB) both in its bulk and in confined states. Using dielectric spectroscopy, we provide experimental evidence depicting a profound influence of surface roughness on the α-relaxation dynamics and the isothermal crystallization of this vapor-deposited glass. Besides, we have verified the influence of film confinement on varying values of surface roughnesses as well. At a fixed surface roughness value, the confinement could alter both the dynamics and crystallization of vapor-deposited CXB.

1 February 2019 in Nano-Structures & Nano-Objects
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Journal Article
Closed access
JJJemy James
Jemy James
AUAparna Beena Unni
Aparna Beena Unni
KTKhadidja Taleb
Khadidja Taleb
Jean-Paul ChapelJean-Paul Chapel
Jean-Paul Chapel
NKNandakumar Kalarikkal
Nandakumar Kalarikkal
YGYves Grohens
Yves Grohens

10 September 2021 in Macromolecules
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Journal Article
Open access
CKChat Katarzyna
Chat Katarzyna
WTWenkang Tu
Wenkang Tu
AUAparna Beena Unni
Aparna Beena Unni
KAKarolina Adrjanowicz
Karolina Adrjanowicz
The physicochemical properties of polymers can be modified by spatial configuration. Here, dielectric spectroscopy (DS) was employed to investigate the effect of the tacticity on the glass-transition dynamics of confined polymer films. We have also carried out dielectric relaxation studies at ambient and elevated pressure conditions. High-pressure measurements provide information on the sensitivity of the glass-transition dynamics to density changes, which can be helpful to better understand the confinement effect. For our study, we have chosen a glass-forming polymer, poly(methyl methacrylate) (PMMA), with two different tacticities (isotactic and syndiotactic) and an approximately equal molecular weight. We have shown that the segmental relaxation for the bulk syndiotactic PMMA is observed at a higher temperature range compared to the bulk isotactic PMMA. The experimental data analysis has also revealed that the molecular order influences the behavior of the polymer under increased pressure. The glass-transition dynamics of isotactic PMMA is more sensitive to the pressure/density changes than syndiotactic PMMA. Finally, we have also demonstrated that tacticity has a significant impact on the segmental dynamics of the confined polymer films. Syndiotactic PMMA has a stronger interaction with the substrate than isotactic PMMA, which is indicated by the higher amount of irreversibly adsorbed polymer chains. For this reason, the segmental dynamics of s-PMMA thin films follows the bulk behavior. In contrast, for i-PMMA, the confinement effects are pronounced, and the glass-transition dynamics accelerate with the reduction of the thickness of thin films.

28 May 2021 in The Journal of Physical Chemistry B
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Journal Article
Open access
RWRoksana Winkler
Roksana Winkler
AUAparna Beena Unni
Aparna Beena Unni
WTWenkang Tu
Wenkang Tu
CKChat Katarzyna
Chat Katarzyna
KAKarolina Adrjanowicz
Karolina Adrjanowicz
Geometric nanoconfinement, in one and two dimensions, has a fundamental influence on the segmental dynamics of polymer glass-formers and can be markedly different from that observed in the bulk state. In this work, with the use of dielectric spectroscopy, we have investigated the glass transition behavior of poly(2-vinylpyridine) (P2VP) confined within alumina nanopores and prepared as a thin film supported on a silicon substrate. P2VP is known to exhibit strong, attractive interactions with confining surfaces due to the ability to form hydrogen bonds. Obtained results show no changes in the temperature evolution of the α-relaxation time in nanopores down to 20 nm size and 24 nm thin film. There is also no evidence of an out-of-equilibrium behavior observed for other glass-forming systems confined at the nanoscale. Nevertheless, in both cases, the confinement effect is seen as a substantial broadening of the α-relaxation time distribution. We discussed the results in terms of the importance of the interfacial energy between the polymer and various substrates, the sensitivity of the glass-transition temperature to density fluctuations, and the density scaling concept.