Browsing by Author "Pubali Adhikary"

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A Laboratory Study on Application of Synthesised Amylopectin-grafted-Polyacrylamide (AP-g-PAM) on Coal Mine Haul Road Dust Emission at Different Atmospheric Temperatures
(Springer, 2024) Vivek Kumar Kashi; N.C. Karmakar; S. Krishnamoorthi; Pubali Adhikary; Atma Ram Sahu
In this study, a laboratory work was carried out to investigate the effectiveness of synthesised amylopectin-grafted-polyacrylamide (AP-g-PAM) vis-a-vis tap water to control the emission of fugitive dust from haul road of opencast coal mine. AP-g-PAM was synthesised by free radical initiator solution technique. Characterisation of AP-g-PAM was done by 1H NMR spectroscopy, FTIR spectroscopy, TGA, and intrinsic viscosity measurements. Size distribution of dust sample was done by sieve analysis. Effects of water and that of polymer solution were tested experimentally on dust samples collected from haul road of a mine for the moisture retention capacity at three atmospheric temperatures, namely 25 °C, 35 °C and 45 °C for 8 h duration. Dust emission rate from haul road has been estimated using an empirical equation. From the results, it is found that the AP-g-PAM added solution has high effectiveness to control dust emission than the water alone. Also, it is observed that the effectiveness of polymeric chemical suppressant is highly depended on atmospheric temperature prevailing at the site. © The Institution of Engineers (India) 2023.
Corrigendum to “Preparation, characterization and electrical properties of alkali metal ions doped co-polymers based on TBF” [Mater. Sci. Eng. B 262 (2020) 114687](S092151072030194X)(10.1016/j.mseb.2020.114687)
(Elsevier Ltd, 2021) Rudramani Tiwari; Ekta Sonker; Devendra Kumar; Krishna Kumar; Pubali Adhikary; S. Krishnamoorthi
The authors regret to inform that in our published manuscript unfortunately we forgot to acknowledge one funding agency i.e. Council of Scientific and Industrial Research, New Delhi, India, which provides stipend to one of the author (First Author) Rudramani Tiwari. So we need to include “Rudramani Tiwari is grateful to Council of Scientific and Industrial Research (09/013(0874)/2019-EMR-I), New Delhi, India, for the financial support” in the Acknowledgement section. © 2020 Elsevier B.V.
Corrigendum to “Synthesis of in-situ doped hydrazine-oxalyl chloride based polyamides and their ionic conductivity studies” [J. Phy. Chem. Sol. 41 (2020) 109424] (Journal of Physics and Chemistry of Solids (2020) 141, (S0022369719326769), (10.1016/j.jpcs.2020.109424))
(Elsevier Ltd, 2021) Rudramani Tiwari; Ekta Sonker; Dipendra Kumar Verma; Krishna Kumar; Pubali Adhikary; S. Krishnamoorthi
The authors regret to inform that in our published manuscript unfortunately we forgot to acknowledge one funding agency i.e. Council of Scientific and Industrial Research, New Delhi, India which provides stipend to one of the author (First Author) Rudramani Tiwari. So we need to include “Rudramani Tiwari is grateful to Council of Scientific and Industrial Research, India (09/013(0874)/2019-EMR-I), New Delhi, India for the financial support” in the Acknowledgement section. © 2021 Elsevier Ltd
Dendrimer like star polymer based on β-cyclodextrin with ABC type miktoarms
(Royal Society of Chemistry, 2016) Kranthikumar Tungala; Pubali Adhikary; Venkanna Azmeera; Krishna Kumar; K. Ramesh; S. Krishnamoorthi
The present article reports the synthesis and self aggregation study of a novel dendrimer like star polymer based on β-cyclodextrin (β-CD), in which the primary alcoholic arms of β-CD have been linked to ABC type miktoarm star polymers. Initially, 6-heptaazido-6-deoxy-β-cyclodextrin (7N3-β-CD) has been clicked with alkyne terminated poly(methyl methacrylate) (alkynyl-PMMA-Br), which has been synthesized through atom transfer radical polymerization technique. Subsequently, azidation has been done in order to prepare β-CD(PMMA-N3)7. Parallelly, an amphiphilic block copolymer (alkynyl-PDLL-b-PNIPAAm), having an alkyne end group, has been synthesized by employing a mikto functional initiator having alcohol, xanthate and alkyne functionalities, in ring opening polymerization (ROP) of d,l-lactide (DLL) from -OH end, and reversible addition-fragmentation chain-transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAAm) from xanthate end. Then, the desired star polymer has been synthesized by the click reaction between β-CD(PMMA-N3)7 and alkynyl-PDLL-b-PNIPAAm. The polymers have been characterized by 1H NMR, and gel permeation chromatography. Self aggregation of the star polymers has been investigated by 1H NMR and fluorescence spectroscopy. Size of the micelles formed has been analyzed by dynamic light scattering and transmission electron microscopic techniques. © 2016 The Royal Society of Chemistry.
Dendritic star polymer of polyacrylamide based on a β-cyclodextrin trimer: a flocculant and drug vehicle
(Royal Society of Chemistry, 2017) Kranthikumar Tungala; Pubali Adhikary; Venkanna Azmeera; Krishna Kumar; S. Krishnamoorthi
The present investigation involves a water treatment study of polyacrylamide (PAM), and star polymers of polyacrylamide based on β-cyclodextrin (β-CD-PAM) and β-cyclodextrin trimer (3-β-CD-PAM). Studies on the drug loading and in vitro drug release of diclofenac sodium (DS) and doxorubicin (DOX), separately, using β-CD-PAM and 3-β-CD-PAM have also been conducted. β-CD-PAM and 3-β-CD-PAM, synthesized by grafting PAM onto β-cyclodextrin (β-CD) and β-cyclodextrin trimer (3-β-CD), respectively, have been employed as flocculants for kaolin suspensions and in the removal of methylene blue (MB) dye. In flocculation and dye removal tests 3-β-CD-PAM has exhibited the better performance among the three polymers. β-CD-PAM and 3-β-CD-PAM have been loaded with DS to prepare drug loaded polymers viz. β-CD-PAM-DS and 3-β-CD-PAM-DS respectively, and with DOX to prepare β-CD-PAM-DOX and 3-β-CD-PAM-DOX respectively. The loading of the drugs has been examined by UV analysis, dynamic light scattering and atomic force microscopy (AFM) techniques. Furthermore, the drug loaded polymers have been employed in an in vitro drug release study in phosphate buffer solution (PBS) at 37 ± 0.5 °C and pH 7.4. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Development of Na+ ion conducting solid biopolymer electrolytes based on Na-CMC-SPA hydrogel
(Elsevier Ltd, 2023) Dipendra Kumar Verma; Rudramani Tiwari; Devendra Kumar; Shashikant Yadav; Km Parwati; Pubali Adhikary; S. Krishnamoorthi
Solid polymer electrolytes based on biopolymers are green and environment-friendly materials. Here, solid biopolymer electrolyte (SBPE) hydrogel based on carboxymethyl cellulose is introduced for Na+ ion-based energy storage material. The synthesized SBPE material is biodegradable and shows excellent strength with good flexibility and high elasticity. SBPE-2 has compact packing with inner porous morphology which is helpful in ionic conduction inside the matrix. The ionic conductivity of electrolyte material was recorded in the range of 10-5 S/cm at room temperature and 10-4 S/cm at higher temperatures (>40 °C). The ionic transference number is found to be > 96% in 510 sec. LSV measurements confirm that the SBPEs material can be used in device fabrication up to 2.3 V. These properties of electrolytes make them a promising material for application in energy storage devices. © 2023 Elsevier B.V.
Introduction of Al(III)-Ion-Based Solid Polymer Electrolyte Material for Energy Storage Device Applications
(John Wiley and Sons Inc, 2023) Dipendra Kumar Verma; Rudramani Tiwari; Devendra Kumar; Shashikant Yadav; Pubali Adhikary; S. Krishnamoorthi
Solid phase electrolyte system PVIm-R-PEG-AlCl3 is introduced for Al(III) ion-based energy storage material. Here, we introduced [AlCl3Br]− counter anion system with N-octyl-polyvinyl imidazolium polymer matrix supported by PEG. Electrolyte material shows good thermal stability with a Glass transition temperature (Tg~148 °C), which provides a good working temperature range for material processing. PVIm-R-PEG-AlCl3 shows electrochemical stability of 1.5 V and red-ox properties, it has 96 % of ionic conduction against the Al metal. The conductivity of electrolyte material is found in the range of 10−5 S/cm at room temperatures and 10−4 S/cm at higher temperature (>40 °C). The polymer electrolyte matrix shows the mobility of 1.37×10−6 m2/Vs and drift ionic velocity of 3.42×10−4 m/s at 30 °C. The ionic movement of Al(III) ions inside the matrix follows correlated type hopping with the activation energy of 0.266 eV. This Al(III) ion-based solid polymer electrolyte (SPE) is associated with a large amount of capacitance with a tiny electrode contribution. © 2023 Wiley-VCH GmbH.
Ionic liquid supported chitosan-g-SPA as a biopolymer-based single ion conducting solid polymer electrolyte for energy storage devices
(Elsevier B.V., 2024) Rudramani Tiwari; Km Parwati; Dipendra Kumar Verma; Devendra Kumar; Shashikant Yadav; Rajshree Rai; Krishna Kumar; Pubali Adhikary; S. Krishnamoorthi
This article discusses the preparation of different grades of single-ion conducting quasi-solid polymer electrolytes (q-SPE) material (Chit-g-SPA-IL) based on biopolymer (chitosan), polyacrylic acid and DBU-acetate (DBUH+ AcO−) ionic liquid. Chit-SPA-60 %-IL exhibited the highest conductivity within the range of 10−4 S/cm. TGA analysis demonstrated the stability of electrolytes up to a temperature of 120 °C. SEM-EDS analysis unveiled the porous nature of the electrolyte and even distribution of ions throughout the matrix. It exhibited an electrochemical stability window (EWS) of 2.53 V with significant current density and an ionic transference number (ITN) of ~99.9 %. The temperature-dependent conductivity established an Arrhenius-type conduction mechanism with an activation energy of 0.149 eV for ion movement within the electrolyte matrix. The AC conductivity analysis emphasized the time-temperature independence of the ionic conduction mechanism. Dielectric analysis highlighted the capacitive nature of the electrolyte, underlining its substantial capacitance, while modulus studies indicated minimal influence from the electrode-electrolyte interface. Chit-SPA-60 %-IL at 30 °C included a self-diffusion coefficient of 4.57 × 10−5 m2/s, ionic mobility of 1.75 × 10−3 m2/Vs, and drift ionic velocity of 0.44 m/s. These findings makes SPE as a promising candidate for sodium-ion-based energy storage devices. © 2024 Elsevier B.V.
Isomeric polythiophene: a promising material for low voltage electronic devices
(Royal Society of Chemistry, 2024) Devendra Kumar; Rudramani Tiwari; Dipendra Kumar Verma; Shashikant Yadav; Km Parwati; Pubali Adhikary; S. Krishnamoorthi
In this investigation, we present empirical observations detailing the manifestation of substantial negative capacitance (NC), reaching up to −1 F, within iodine-doped isomeric polythiophene (IPTh-I2). NC observed in our case is not transient but stable enough to be measured for as long as the optimum concentration of the iodine dopant is available. In contrast, undoped isomeric polythiophene (IPTh) manifests a modest positive capacitance ranging from 30 to 60 μF. The concatenation of IPTh-I2 and IPTh in the series results in an augmentation of the total capacitance of the system (∼170 μF), exemplifying a characteristic feature of NC. Conversely, a bilayer configuration consisting of IPTh:IPTh exhibits a reduction in total capacitance by 38%. A notable amplification in the dielectric constant, escalating from 30 in IPTh to approximately 2000 in IPTh-I2, signifies extensive conformational and structural alterations arising from interactions between the doped polymer chain and various iodide species, attributing to the emergence of NC. Furthermore, we document a single-sided p-n junction diode with a low knee voltage (below 0.5 V) as a model device, illustrating the potential of IPTh as a promising material for the design and development of negative capacitance-based field-effect transistors. This research offers avenues for the scientific community to conceive low knee voltage-operating diodes, transistors, supercapacitors, and various other electronic devices based on all-organic semiconductors. © 2024 The Royal Society of Chemistry.
Negative capacitance based on isomeric polythiophene in action
(Royal Society of Chemistry, 2024) Devendra Kumar; Rudramani Tiwari; Dipendra Kumar Verma; Shashikant Yadav; Km. Parwati; Rajshree Rai; Pubali Adhikary; S. Krishnamoorthi
In this study, we demonstrated that arranging positive and negative capacitance materials in series, based on isomeric polythiophene, led to a notable increase in total capacitance. Furthermore, the application of negative capacitance (NC) technology in supercapacitor (SC) construction offers the potential for energy storage capabilities surpassing fundamental limits. Our findings suggest the feasibility of developing all-organic based energy storage devices with high capacitance. © 2024 The Royal Society of Chemistry.
One-pot synthesis of electroconducting graphene coated silver nanoparticles from silver acetylide
(Springer Science and Business Media B.V., 2021) Devendra Kumar; Rudramani Tiwari; Rajiv Kumar Patel; Pubali Adhikary; S. Krishnamoorthi
Herein, we have reported a new, efficient and one pot methodology for the synthesis of graphene coated silver nanoparticles (GCAgNPs) from an organosilver compound (Silver Acetylide) itself. Synthesis of (GCAgNPs) from silver acetylide has been carried out in anhydrous DMF at 150 °C and completed in 1.5 h. Appearance of surface plasmon resonance peak at 426 nm confirms the formation of silver nanoparticles. Presence of graphene over silver nanoparticle has been proved by UV–Vis (π-π* transition at 273 nm) and Raman spectrum (G and D band at 1586 and 1408 cm−1, respectively). TEM analysis of silver nanoparticles shows the formation of spherical shaped nanoparticles with agglomeration to variable extent. Four-point Probe methods has been applied for studying the electrical conductivity of the nanoparticles, which exhibit the conductivity of GCAgNPs to be 4.42 × 104 S/m. These GCAgNPs will find its application in various fields of photovoltaics. Graphical abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to Springer Nature B.V.
Phase transformation and plasmonic damping study for semi-solid ionic polymeric hydrogel system at higher temperature and low radio frequency
(Elsevier B.V., 2024) Rudramani Tiwari; Devendra Kumar; Dipendra Kumar Verma; Shashikant Yadav; Km Parwati; Pubali Adhikary; S. Krishnamoorthi
This article represents the findings regarding the phase transitions exhibited by a polymeric hydrogel material composed of sodium polyphosphate-polyethylene glycol. These transitions play a crucial role in the generation of ionic plasmons and the manifestation of surface plasmon resonance (SPR) with dielectric permittivity damping within the polymer electrolyte system of the hydrogel. Usually, SPR has been observed in electron-conducting systems within an optical frequency range. However, here SPR is observed in an ionic system within a lower radio frequency range of 104-10 (Parwati et al., 2024) 77 Hz for temperatures exceeding 80 °C. The mechanism responsible for permittivity damping can be elucidated by considering the accumulation of ionic charges at the interface between the electrode and the electrolyte, coupled with a high degree of charge absorption following the Drude model. A power law has been used to describe the resonance that occurs between the applied DC frequency and the motion of charge carrier ions, thus confirming the presence of free ionic motion within the hydrogel matrix. tan δ shows significant energy absorption further substantiating permittivity damping, which transitions from positive to negative values. © 2024 The Authors
Preparation of ultra-high-molecular-weight polyacrylamide by vertical solution polymerization technique
(John Wiley and Sons Inc, 2019) Ekta Sonker; Rudramani Tiwari; Pubali Adhikary; Krishna Kumar; S. Krishnamoorthi
A straightforward and novel methodology has been developed for the synthesis of ultra-high-molecular weight polyacrylamide (PAM) by vertical solution polymerization technique. By varying the concentrations of acrylamide monomer, three different grades of polymers (PAM-V1, PAM-V2, and PAM-V3) have been synthesized and compared with the series of different grades of PAM (PAM-C1, PAM-C2, and PAM-C3) synthesized through conventional solution polymerization technique. The synthesized grades PAM-V1, PAM-V2, PAM-V3, PAM-C1, PAM-C2, and PAM-C3 have been characterized by 1H NMR, infrared spectroscopy, intrinsic viscosity measurement, molecular weight determination by gel permeation chromatography, and thermal analysis. Rheological analysis has been carried out on the aqueous solutions of various grades of PAMs. Swelling behavior of ultra-high-molecular weight PAMs has also been investigated. The flocculation performances of all grades have been investigated in kaolin suspension by settling and jar test methods. POLYM. ENG. SCI., 59:1175–1181 2019. © 2019 Society of Plastics Engineers. © 2019 Society of Plastics Engineers
Preparation, characterization and electrical properties of alkali metal ions doped co-polymers based on TBF
(Elsevier Ltd, 2020) Rudramani Tiwari; Ekta Sonker; Devendra Kumar; Krishna Kumar; Pubali Adhikary; S. Krishnamoorthi
Click reaction method led to the formation of polymeric structures with 1,2,3-triazoles. By applying methodology we have synthesized thiophene-bisphenyl fluorene (TBF) based co-polymer, containing triazole ring on its back-bone and doped it with Li+, Na+ and K+ metal ions. Upon doping with these metal ions, the non-conducting (TBF) polymer becomes ionic conducting in nature i.e. (TBF)n− (Li+)n, (TBF)n− (Na+)n, and (TBF)n− (K+)n. Among the all doped polymers, K+ doped polymer shows best conductivity (conductivity ~ 2.5 × 10−4 S/cm), low band gap, low activation energy, dielectric properties, capacitance, dielectric permittivity loss, dielectric loss and electrical modulus. These properties of solid polymeric electrolytic materials make it more useful in the field of organic voltaics. © 2020
Reducing the dust generation of haul road by improving water holding capacity with the application of synthesised polyacrylamide at Laboratory Condition
(Technoscience Publications, 2020) Vivek Kumar Kashi; N.C. Karmakar; S. Krishnamoorthi; Ekta Sonker; Pubali Adhikary; Rudramani Tiwari
Surface mining method enormously affects the environment in terms of fugitive dust emission than underground mining method. All the several sources of dust emission from opencast mining, haul road transportation system are the main source of fugitive dust. In this research article, a biodegradable polyacrylamide (PAM) was used to suppress dust generation from haul road of mine. It improves the moisture carrying capacity of haul road than the water. PAM has been synthesized by free radical polymerization process using ceric ammonium nitrate initiator. It was characterized by 1H NMR, IR & intrinsic viscosity measurements, whereas size distribution of haul road dust was measured by sieve analysis. Laboratory work has been carried out to investigate the water holding capacity of haul road dust particles using PAM solution and compared with only water for 8 hours duration. The temperature of the chamber was kept constant at 35°C while relative humidities (RH) varied from 40% to 70%. It was observed that moisture retention of dust with the application of PAM solution and only water were 25.65% and 20.4% at 70% RH and 7.14% and 1.65% at 40% RH, respectively after 8 hours. © 2020 Technoscience Publications. All rights reserved.
Room temperature polymerization of vinylic monomers by azo initiator
(2013) Krishna Kumar; Pubali Adhikary; S. Krishnamoorthi
The azo initiator, sodium-{4-(4-hydroxy-phenylazo)-benzenesulfonate (SHPBS)}, has been synthesized by coupling reaction with sodium-(p-sulfonate benzene diazonium chloride) and phenol. Unsymmetrical azo group leading to weak azo bond in case of SHPBS resulted in dissociation at lower temperature (25°C) to produce free radicals. Its versatile solubility (soluble in aqueous and organic solvents), generation of free radicals at 25°C, and its application without mechanical stirring are the added greater advantage over commercially available azo initiators (AIBN, etc.). The SHPBS has been characterized by FTIR, 1H-NMR spectroscopies, and thermal analysis. It has been observed that various monomers such as AM, AA, IPAM, and AMPS which have been polymerized with SHPBS have led to high molecular weight polymers at shorter reaction time. © 2012 Wiley Periodicals, Inc.
Single-Ion-Conducting SPP-SPA Blend Hydrogel-Based Pseudo-Solid Polymeric Electrolyte Material for Na+-Ion Constructed Energy Storage Devices
(American Chemical Society, 2022) Rudramani Tiwari; Dipendra Kumar Verma; Devendra Kumar; Shashikant Yadav; Krishna Kumar; Pubali Adhikary; S. Krishnamoorthi
A pseudo-solid blend polymeric hydrogel electrolyte material, sodium polyphosphate (SPP)-sodium polyacrylate (SPA), is successfully synthesized by using SPP and SPA in an aqueous medium. Large anionic polymer chains with small Na+ cations allow movement of cations only inside the matrix and make it a Na+-ion-based single-ion-conducting electrolyte. SPP-SPA has a gel matrix with good elasticity, flexibility, and adhesive property, which allow better transport of ions inside the matrix with a good electrode-electrolyte interface. Because water molecules present inside the matrix act like a water-in-salt electrolyte, it shows an electrochemical stability window of 2 V with good current density. This single-ion-conducting electrolyte shows a cationic transport number of ≈97%. The electrolyte shows room-temperature conductivity, matrix diffusivity constant, ionic mobility, and drift ionic velocity in the order of 10-4 S/cm, 10-8 m2/s, 10-6 m2/V s, and 10-3 m/s respectively. This electrolyte material follows a cage-type (n > 1) ionic conduction mechanism with the requirement of a low amount of activation energy, that is, 0.314 eV. A high amount of capacitance is associated with the electrolyte that has an insignificant electrode contribution. This SPP-SPA pseudo-solid polymeric electrolyte can be used as a highly promising smart material for energy storage and capacitor applications. © 2022 American Chemical Society.
Sodium-Ion-Conducting Alginate-Based Electrolyte Material for Energy Storage Applications
(John Wiley and Sons Inc, 2025) S. P. Yadav; Dipendra Kumar Verma; Rudramani Tiwari; Devendra Kumar; Km Parwati; Rajshree N. Rai; Pubali Adhikary; S. Krishnamoorthi
A green pseudosolid polymer electrolyte is prepared using sodium alginate and sodium polyphosphate via a sustainable solution-cast method with water as the medium. The amorphous anionic polymer backbone enables easy cationic movement, enhancing ionic conductivity. This water-in-salt electrolyte exhibits an electrochemical stability window of 3.2 V and a cationic transport number of 0.90%. Thermal analysis confirms stability up to 150 °C, making it suitable for high-temperature applications. X-ray diffraction analysis verifies its amorphous nature, facilitating smooth ion transport, while scanning electron microscopy reveals a smooth morphology with well-defined pores, improving electrode interface stability. At room temperature, the electrolyte displays electrical conductivity around 10−5 S cm−1, increasing to 10−4 S cm−1 above 40 °C. The drift ionic velocity is ≈10−5m s−1, with ionic mobility of 10−7 mV s−1. Cage-type hopping dominates ionic movement, requiring a low activation energy of 0.158 eV. Incorporating an ionic liquid as a plasticizer further enhances conductivity to 10−3S cm−1. Additionally, the material exhibits dielectric relaxation due to polar group orientation. Its high capacitance with minimal electrode contribution makes it a promising candidate for energy storage applications, offering excellent electrochemical and thermal stability, along with superior electrode–electrolyte interface properties. © 2025 Wiley-VCH GmbH.
Sodium-Ion-Conducting Hydrogel Material: Synthesis, Characterization and Conductivity Studies
(John Wiley and Sons Inc, 2023) Shashikant Yadav; Dipendra Kumar Verma; Rudramani Tiwari; Devendra Kumar; Km Parwati; Rajshree Rai; Pubali Adhikary; S. Krishnamoorthi
Herein we have reported single sodium ion conducting pseudo solid polymer electrolyte material, was synthesized successfully using sodium; 3,4,5,6-tetrahydroxyoxane-2-carboxylate (ALG) and sodium salt of poly (acrylic Acid): SPA in the water as solvent via solution cast technique. This pseudo-solid polymer material allows Na+ cation transport inside the matrix. The FTIR technique confirmed the appreciable interaction between the sodium alginate and sodium polyacrylate polymer. This amorphous polymer material has good flexibility, tensile strength, and good elasticity which provides a better electrode-electrolyte interface. The material shows electrical conductivity in the range of 10−5 S/cm at room temperature and 10−4 S/cm at higher temperatures (>40 °C). The material shows electrochemical stability of 2.26 V owing to a very good amount of current density with ≈97 % ionic transport number for the sodium ion. The material shows drift ionic velocity in the range of 10−4 m/s and ionic mobility in the order of 10−6 m2/Vs at room temperature. It shows the matrix ionic diffusivity constant in the order of 10−7 m2/s. It possesses low activation energy for ionic movement inside the matrix of 0.465 eV. The matrix shows the correlated type of hopping. An appreciable amount of capacitance is associated with the matrix with minute electrode contribution. © 2023 Wiley-VCH GmbH.
Solution and microwave assisted synthesis of β-Cyclodextrin grafted polyacrylamide: Water treatment and In-vitro drug release study
(Elsevier B.V., 2017) Venkanna Azmeera; Kranthikumar Tungala; Pubali Adhikary; Krishna Kumar; S. Krishnamoorthi
The present article reports the application of β-cyclodextrin grafted polyacrylamides synthesized through solution and microwave assisted polymerization techniques as flocculants and then the employment of partially hydrolyzed products of best grade of each technique in-vitro drug release study of diclofenac sodium. Five different grades of β-cyclodextrin grafted polyacrylamides by each of solution and microwave assisted polymerization techniques have been synthesized, by varying the monomer concentration. The synthesized polymers have been well characterized and their flocculation performances have been evaluated in kaolin suspension through settling and jar test methods Then the best performing grades of both the techniques have been partially hydrolyzed to prepare three different grades each technique by varying the concentration aqueous NaOH solution. Flocculation efficiencies of these polymers have been investigated in kaolin suspension. Thus best grades of partially hydrolyzed grafted polymers of each technique have been chosen for further study of drug delivery. In-vitro drug release study has been done using diclofenac sodium loaded microbeads prepared by ionic gelation method with two partially hydrolyzed grafted polymers (one from each technique) in phosphate buffer solution (PBS) at 37 ± 0.5 ○C and pH 7.4. The drug load and release have been analyzed by UV–vis spectroscopy. © 2017 Elsevier B.V.