Browsing by Author "Kranthikumar Tungala"

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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.
Fabrication of low cost thermoresponsive microgel@CuO catalyst for rapid reduction of methylene blue dye
(Springer Science and Business Media B.V., 2024) Tarkeshwar Prasad; Poorn Prakash Pande; Krishna Kumar; Shailja Rai; Aradhana Chaudhary; Anupam Das; Rudramani Tiwari; Kranthikumar Tungala; Vinai Kumar Singh
Azo dyes which are carcinogenic and mutagenic in nature are hazardous water pollutants. The present study details the catalytic reduction of methylene blue (MB) dye. In this research, the synthesis of microgels was achieved through free-radical emulsion polymerization by employing 2-hydroxyethyl methacrylate as a monomer as well as the crosslinker. The other monomers used in the synthesis of the microgels are styrene, acrylamide and N-vinylcaprolactam (NVCL). Three different grades of microgel have been synthesized by varying the amount of NVCL while keeping other monomer amounts constant. Further, copper-oxide nanoparticles have been incorporated into polymeric microgels through hydrothermal methods for catalytic reduction applications. Characterizations of both microgels and microgel-nanoparticle composites have been conducted using various techniques viz., Fourier transform infrared spectroscopy, powder X-Ray diffraction, dynamic light scattering, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The catalytic reduction of MB was studied by using ultraviolet-visible spectrophotometer. The catalytic reduction efficiency has been determined by optimizing the parameter effects of crosslinking, temperature responsive monomer feed, temperature and amount of reducing agent (NaBH4). Microgel nanocomposites have responded well in efficient catalysis at higher NVCL feed with moderate dose of NABH4. © The Polymer Society, Taipei 2024.
Fabrication, characterization and flocculation properties of starch, chitosan or cellulose based graft copolymers: A review
(Elsevier Ltd, 2025) Shubhangi Pandey; Anmol Kumar; Krishna Karthik Kumar; S. Krishnamoorthi; Kranthikumar Tungala
Wastewater treatment has been most obligatory, as food industries, pharmaceutical companies, textile mills, etc., are disposing of their wastes in water bodies. Graft copolymers, in which synthetic polymers are grafted on backbones of natural polymers of diverse sources, have come into light for contaminated water treatment. In this review article, we have mounted up various synthesis methods used, along with their corresponding mechanisms, for the fabrication of starch, chitosan or cellulose based graft copolymers. Characterization techniques that are commonly used for the confirmation of the fabricated graft copolymers have been discussed. Further, the process of flocculation, its influencing factors, and mechanisms involved in flocculation have been detailed. This review also explores the treatment of wastewater discharged from several industries, which includes toxic heavy metal ions, harmful dyes, coalmine dust, mining waste, and paper and pulp industrial middle effluent. Further, saline retention, sludge dewatering, and microalgal biomass harvesting have been detailed. © 2025 Elsevier Ltd
Micellization of amphiphilic host–guest inclusion complexes of polymers based on β–cyclodextrin trimer and adamantane
(Elsevier B.V., 2020) Kranthikumar Tungala; Krishna Kumar; Ekta Sonker; S. Krishnamoorthi
The present work aims to study the self–aggregation of amphiphlic miktoarm star polymers synthesized via the inclusion complexation of adamantyl terminated poly(methyl methacrylate) (ADM–PMMA) guest, into β–cyclodextrin grafted polyacrylamide (β–CD–PAM) and β–cyclodextrin trimer (3–β–CD) grafted polyacrylamide (3–β–CD–PAM) star polymer hosts, separately. β–CD and 3–β–CD based hosting star polymers have been synthesized through solution polymerization technique and the guest adamantyl terminated poly(methyl methacrylate) through the technique of atom transfer radical polymerization (ATRP) by using an adamantine–based ATRP initiator. Further, the guest polymer has been incorporated into the host polymer via molecular recognition between adamantyl moiety and β–CD. Construction of β–CD–PAM–b–ADM–PMMA and 3–β–CD–PAM–b–ADM–PMMA miktoarm star polymers has been examined by 1H NMR and 2D 1H NOESY NMR spectra. Their critical micellar concentrations have been estimated by using fluorescence spectroscopy. Further, sizes of the self–aggregates have been anticipated by dynamic light scattering and transmission electron microscopic investigations. © 2020 Elsevier B.V.
pH tempted Micellization of β-Cyclodextrin based Diblock copolymer and its application in solid/liquid separation
(Springer, 2020) Kiran Kiran; Rudramani Tiwari; Kranthikumar Tungala; S. Krishnamoorthi; Krishna Kumar
This work focuses on facile synthesis of pH responsive diblock copolymers based on acrylamide (AM) and 2-Acrylamido-2-methyl-1-propane sulfonic acid (AMPS) grafted on β-Cyclodextrin and have application in solid/liquid separation. β-CD based chain transfer agent (CTA) has been synthesized by one pot synthesis method. Three different grades of β-Cyclodextrin based Macro CTA were synthesized through RAFT polymerization technique. Macro CTA have been used further in synthesis of five different grades of β-CD grafted pH-responsive diblock copolymers i.e. (β-CD-PRP’s) by varying the amount of AMPS. The polymeric materials were characterized by Fluorescence Spectroscopy, FT-IR, GPC, 1H-NMR, SEM, TEM, TGA, and XRD. β-CD-PRP’s shows their micellization properties at acidic pH < 6.57 with polymer conc. > 0.336 mg/mL and has also been studied for removal of model contaminant (kaolin). Among all grades of diblock copolymers, grade 3 shows best performance in the removal of kaolin from aqueous solution at 7 and 5 pH values. [Figure not available: see fulltext.]. © 2020, The Polymer Society, Taipei.
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.
Synthesis of IONP's decorated graft copolymers and study of their magnetic force–induced wastewater treatment
(John Wiley and Sons Ltd, 2020) Kiran; Ekta Sonker; Kranthikumar Tungala; S. Krishnamoorthi; Krishna Kumar
Our work is focused on facile synthesis and modification of amylopectin-grafted block copolymers by using reversible addition−fragmentation chain transfer (RAFT) polymerization technique. This technique yields polymers with controlled molecular weight and low polydispersity indexes and is feasible with a wide range of monomers. Five different grades of amylopectin-grafted polymethacrylic acid and polyacrylamide block copolymers have been synthesized via RAFT, by varying the amount of acrylamide employing amylopectin-based macro chain transfer agent. Graft copolymers have been upgraded as smart responsive graft copolymers, through the incorporation of iron oxide nanoparticles (IONPs) via condensation reaction. The polymeric materials have been extensively characterized by energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy, proton magnetic resonance spectroscopy, scanning electron microscopy, ultraviolet-visible spectroscopy, gel permeation chromatography, transmission electron microscopy, thermogravimetric analysis, and X-ray diffraction analysis. Normal and responsive graft copolymers have been studied for removal of model contaminant (kaolin), and responsive graft copolymers have been used to remove methylene blue dye (without using any adsorbent) from water by applying external magnetic field. The upgraded block copolymers have shown best performance in wastewater treatment. © 2019 John Wiley & Sons, Ltd.
Synthesis, characterization, and in vitro drug release study of 3-arm poly-β-alanine
(John Wiley and Sons Inc, 2015) Krishna Kumar; Pubali Adhikary; Kranthikumar Tungala; Venkanna Azmeera; S. Krishnamoorthi
Synthesis of three arms star-shaped poly-β-alanine (3-b-ala) based on tri(prop-2-yn-1-yl) benzene-1,3,5-tricarboxylate (TBT) and azido terminated poly-β-alanine (N3-P-ala) was performed using click reaction. TBT was synthesized by nucleophilic substitution reaction between propargyl alcohol and 1,3,5-benzenetricarbonyltrichloride. For the first time, N3-P-ala was synthesized through anionic polymerization of acrylamide using sodium azide as an initiator. TBT was characterized by FT-IR and 1HNMR. N3-p-ala was characterized by FT-IR, GPC, and 1HNMR and 3-b-ala was characterized by FT-IR, GPC, 1HNMR, TGA, and XRD. The synthesized 3-b-ala was used for drug loading and releasing studies. Polymer loaded drug (3-b-ala-D) hybrid was used in in vitro studies of drug (Diclofenac sodium) release in phosphate buffer solution (PBS) at 37 ± 0.5°C and pH 7.4. The drug loading and releasing studies were analyzed by UV-visible spectrophotometer. 3-b-ala-D was examined by AFM to analyze the surface morphology and roughness. © 2015 Wiley Periodicals, Inc.
Trimerization of β-cyclodextrin through the click reaction
(2013) Kranthikumar Tungala; P. Adhikary; S. Krishnamoorthi
Triprop-2-ynyl benzene-1,3,5-tricarboxylate (A) is synthesized by the reaction of 1,3,5-benzenetricarbonyl trichloride with propargyl alcohol and (A) is clicked with mono-6-deoxy-6-azido-β-cyclodextrin (N3-β- CD) in the presence of copper(I) bromide catalyst. N3-β-CD has been prepared from β-cyclodextrin (β-CD) on treatment with toluenesulfonyl chloride (TsCl) and then with sodium azide (NaN3) in two consecutive steps. Further trimer of β-CD is characterized by 1H NMR and FTIR studies. Solubility of β-cyclodextrin (β-CD) in water can be increased by increasing the number of alcoholic OH functionalities and hydrophobic cavities in a molecule by the trimerization of β-CD.