Co-reporter:Radhika Mehta, Rina Kumari, Prolay Das and Anil K. Bhowmick
Journal of Materials Chemistry A 2014 vol. 2(Issue 37) pp:6236-6248
Publication Date(Web):24 Jul 2014
DOI:10.1039/C4TB00854E
A novel tyrosine-based copolymer containing L-tyrosine (Tyr) and diglycidylether of bisphenol A(DGEBA) was synthesized and studied for its interaction with DNA for potential applications in biological systems. The synthesis of the polymer was optimized by varying monomer ratios using 4-(dimethylamino)pyridine (DMAP) as a catalyst to yield polymers with a Mw of 7500–8000. Further characterization by FTIR, NMR and thermal analysis supported the formation of the monotyrosine–DGEBA polymer. The interaction of the 1:1 DGEBA–tyrosine copolymer with DNA was investigated by gel electrophoresis, thermal melting, and fluorescence spectroscopy in ratios ranging from 0.5:1 to 12:1 polymer–DNA (w/w). The copolymer was seen to lend stability to the DNA without damaging it and demonstrated endonuclease resistivity that is conducive for biological applications. Scanning electron microscopy, dynamic light scattering and zeta potential studies of the polymer–DNA complex also established that the polymer is capable of encapsulating DNA leading to the formation of the DNA–polymer polyplex nano-assembly. The potential of the polymer for biological applications was further reinstated by its non-cytotoxicity.
A biodegradable triblock copolymer, poly-D,L-lactide–δ-valerolactone–D,L-lactide, was synthesized by the ring-opening polymerization of δ-valerolactone and the sequential addition of the D,L-lactide monomer to the hydroxyl end of a functionalized poly-δ-valerolactone macroinitiator. The copolymer was then evaluated for its suitability as a drug-delivery vesicle. The effect of the monomer ratio, catalyst and initiator concentration on the structure was investigated using 1H-NMR, 13C-NMR and Fourier transform infrared spectroscopy, and gel-permeation chromatography. 1H-NMR confirmed the presence of the D,L-lactide segment as the terminal segment and δ-valerolactone as the mid-segment. 13C-NMR was used to study the block sequencing and extent of trans-esterification. The crystallization of the triblock was retarded compared with the pure poly-δ-valerolactone homopolymer due to the incorporation of the D,L-lactide moiety at the chain end of the poly-δ-valerolactone segment. The glass transition temperatures of the two blocks shifted depending on the ratio of the two monomers. The triblock, with molecular weights between 5000 and 10000 Da, showed a separated morphology in the nanophase, with alternating stripes of amorphous and crystalline segments (3–6 nm) under transmission electron microscopy. The triblock was then fabricated into microspheres with an average diameter of 17.2 μm and was used to encapsulate salicylic acid. The formation of pores on the surface of the microsphere facilitated the release of the salicylic acid. The release profile displayed the characteristics of a potential carrier.
Co-reporter:Titash Mondal, Anil K. Bhowmick and Ramanan Krishnamoorti
Journal of Materials Chemistry A 2013 vol. 1(Issue 28) pp:8144-8153
Publication Date(Web):07 May 2013
DOI:10.1039/C3TA11212H
Two effects of an organolithium reagent (n-butyl lithium) on graphene and expanded graphite are reported. Its ability to simultaneously scavenge protons and act as a nucleophile leads to a bi-functionalized graphitic system. Subsequent treatment with carbon dioxide gas generates carboxylic functionality at the proton abstraction sites. This technique promises a greener method for single pot carboxylation for graphitic materials. The nucleophilicity of n-butyl lithium leads to efficient grafting of butyl groups. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis are used to prove the success of the reaction. Raman spectroscopy reveals more defect sites for expanded graphite compared to graphene, which leads to a higher degree of functionalization. Atomic force microscopy shows that the functional groups generated are nano-spike-shaped pendant structures attached to the graphene. These functionalized materials are used as adsorbers for efficient and fast removal of water-soluble dyes by non-covalent interaction between the dye and the carboxylic groups of the graphitic system. Spectrometric as well as kinetic studies are reported for crystal violet lactone dye adsorption. Both the modified materials show twice the adsorption capacity of the pristine materials. Superior dye adsorption properties were observed for the modified materials compared to graphene oxide.
Unlike conventional routes by van der Waals forces, a facile and novel approach using covalent bonding is established in the present work to synthesize polyaniline (PANI)-grafted carbon nanofiber (CNF) composites as promising supercapacitors. For this purpose, toluenediisocyanate was initially functionalized to carboxylated CNF via amidation followed by reaction with excess aniline to form a urea derivative and residual aniline, which was subsequently polymerized and grafted with a urea derivative. Amidation of CNF (TCNF) and, consequently, the grafting of PANI on TCNF were verified by IR, Raman, 1H NMR, X-ray photoelectron, and UV–visible spectroscopic methods, X-ray diffraction, and thermogravimetric analysis. Morphological analysis revealed uniform distribution of PANI on the surface of TCNF, indicating strong interaction between them. Electrochemical tests of the composite containing 6 wt % TCNF demonstrated efficient capacitance of ∼557 F g–1 with a capacity retention of 86% of its initial capacitance even after 2000 charge–discharge cycles at a current density of 0.3 A g–1, suggesting its superiority compared to the materials formed by van der Waals forces. The remarkably enhanced electrochemical performance showed the importance of the phenyl-substituted amide linkage in the development of a π-conjugated structure, which facilitated charge transfer and, consequently, made it attractive for efficient supercapacitors.Keywords: carbon nanofiber; chemical grafting; composites; electrochemical properties; polyaniline; supercapacitor;
Journal of Nanoparticle Research 2013 Volume 15( Issue 3) pp:
Publication Date(Web):2013 March
DOI:10.1007/s11051-013-1508-6
Synthesis of RNA-templated Ag/PVA nanobiocomposites of controlled morphology was investigated. Surface morphologies of the composites and size distributions of the nanofillers were analyzed by means of field emission scanning electron microscopy. Interfacial interaction between the different components was followed by monitoring the surface plasmon resonance of silver nanoparticles in nanobiocomposites. The band gap approximations suggested semiconducting behavior of the nanobiocomposites with larger band gap than that of the conventional semiconductors. RNA-stabilized Ag/PVA nanobiocomposites revealed the presence of well-dispersed and spherical Ag nanoparticles in PVA matrix with a size distribution of 14–23 nm. IR spectra of the nanobiocomposites demonstrated the complex behavior of RNA with Ag nanoparticles in the polymer matrix due to the presence of noncovalent interactions (electrostatic/van der Waals) between RNA, Ag, and PVA molecules. The effects of the loading of RNA-capped Ag nanoparticles on the electrical properties of PVA were also observed by analyzing I–V characteristics of nanobiocomposites which displayed a large increase (≈89 %) at low concentration relative to neat PVA. The drastic improvement in optical and electrical properties of the nanobiocomposites indicated their promising applications in nanobiotechnology.
The Journal of Physical Chemistry C 2013 Volume 117(Issue 48) pp:25865-25875
Publication Date(Web):November 20, 2013
DOI:10.1021/jp4097265
A novel chemical approach is explored to design three-dimensional porous network of reduced graphene oxide (GO)/multiwalled carbon nanotube (MWCNT) hybrid from reduced GO connected to MWCNT by sp2 carbons. The process involved simultaneous functionalization, reduction, and stitching of GO by p-phenylenediamine and subsequent diazotization followed by C–C coupling with MWCNT. For comparison, a physical mixture was also prepared. The resulting hybrids were characterized by infrared, Raman, UV–vis, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and scanning tunneling microscopy. The chemical hybrid was shown to exhibit good electrical conductivity (210.48 S m–1), promising specific capacitance (277 F g–1) even at high current density (10 A g–1), remarkable energy density (21.32 W h kg–1) especially at high power density (3.13 kW kg–1), outstanding cyclability (89%) even after 2000 cycles, and good dye adsorption capacity (245 mg g–1) for crystal violet owing to its extended conjugated network, larger surface area, and porous structure. Therefore, the hybrid is attractive for supercapacitors, dye removal, and other electronic applications.
Co-reporter:Shib Shankar Banerjee, Anil K. Bhowmick
Polymer 2013 Volume 54(Issue 24) pp:6561-6571
Publication Date(Web):14 November 2013
DOI:10.1016/j.polymer.2013.10.001
Novel polyamide 6 (PA6)/fluoroelastomer nanostructured thermoplastic elastomeric blends were developed in the present work. The influence of interaction between the components and morphology on physical properties of the blends was analyzed. Scanning electron microscopy and atomic force microscopy studies, solubility and theoretical analysis of complex modulus clearly indicated that PA6 was the continuous matrix in which fluorocarbon elastomer was present in nanoscale. Low torque ratio (0.34) of rubber/plastic, high mixing speed and long mixing time had an important role in developing the nanostructured morphology of the blend. Tensile strength of the thermoplastic elastomer was about 39.0 MPa which was much higher than that reported earlier and showed significant improvement with increasing PA6 content. Large shifting of the glass transition temperature of the rubber and the plastic phases towards the lower temperature compared to those pristine polymers was also observed. The above properties were explained with the help of interaction between the components and morphology.
Co-reporter:Nabarun Roy, Rajatendu Sengupta, Anil K. Bhowmick
Progress in Polymer Science 2012 Volume 37(Issue 6) pp:781-819
Publication Date(Web):June 2012
DOI:10.1016/j.progpolymsci.2012.02.002
The various forms of carbon used in composite preparation include mainly carbon-black, carbon nanotubes and nanofibers, graphite and fullerenes. This review presents a detailed literature survey on the various modifications of the carbon nanostructures for nanocomposite preparation focusing upon the works published in the last decade. The modifications of each form of carbon are considered, with a compilation of structure–property relationships of carbon-based polymer nanocomposites. Modifications in both bulk and surface modifications have been reviewed, with comparison of their mechanical, thermal, electrical and barrier properties. A synopsis of the applications of these advanced materials is presented, pointing out gaps to motivate potential research in this field.
Co-reporter:Titash Mondal, Anil K. Bhowmick and Ramanan Krishnamoorti
Journal of Materials Chemistry A 2012 vol. 22(Issue 42) pp:22481-22487
Publication Date(Web):25 Sep 2012
DOI:10.1039/C2JM33398H
Facile synthesis of a chlorophenyl decorated graphene (CBG) sheet synthesized by a solvent free green diazotization technique is reported here. The functionalization of the material was supported by various characterization techniques including Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and thermal analysis. About 15 percent grafting, as determined by XPS and IR spectroscopy, could be achieved under the conditions employed. The CBG sheet was applied for the first time as a potential antibacterial agent on Gram negative bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus. The antibacterial character was quantified using the MacFarland number technique whereby the volumetric number density of colony forming units was determined. It was also quantified by a Kirby–Bauer test, where the zone formed due to mortality of bacteria caused by chlorine groups attached to the graphene was estimated by a mathematical model. Based on the zone of inhibition created, CBG was found to be more than twice as effective as unmodified graphene and graphene oxide. The synthesis promises to open up a new avenue for the development of chemically converted graphene based antimicrobial agents.
Co-reporter:Rajatendu Sengupta, Mithun Bhattacharya, S. Bandyopadhyay, Anil K. Bhowmick
Progress in Polymer Science 2011 Volume 36(Issue 5) pp:638-670
Publication Date(Web):May 2011
DOI:10.1016/j.progpolymsci.2010.11.003
Carbon materials particularly in the form of sparkling diamonds have held mankind spellbound for centuries, and in its other forms, like coal and coke continue to serve mankind as a fuel material, like carbon black, carbon fibers, carbon nanofibers and carbon nanotubes meet requirements of reinforcing filler in several applications. All these various forms of carbon are possible because of the element's unique hybridization ability. Graphene (a single two-dimensional layer of carbon atoms bonded together in the hexagonal graphite lattice), the basic building block of graphite, is at the epicenter of present-day materials research because of its high values of Young's modulus, fracture strength, thermal conductivity, specific surface area and fascinating transport phenomena leading to its use in multifarious applications like energy storage materials, liquid crystal devices, mechanical resonators and polymer composites. In this review, we focus on graphite and describe its various modifications for use as modified fillers in polymer matrices for creating polymer–carbon nanocomposites.
Vulcanized ethylene propylene diene polymethylene (EPDM) rubber surface was treated in a radio frequency capacitatively coupled low pressure argon/oxygen plasma to improve adhesion with compounded natural rubber (NR) during co-vulcanization. The plasma modified surfaces were analyzed by means of contact angle measurement, surface energy, attenuated total reflection-infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray sulfur mapping and atomic force microscopy. Several experimental variables such as plasma power, length of exposure time and composition of the argon–oxygen gas mixture were considered. It was delineated that plasma treatment changed both surface composition and roughness, and consequently increased peel strength. The change in surface composition was mainly ascribed to the formation of C–O and –CO functional groups on the vulcanized surfaces. A maximum of 98% improvement in peel strength was observed after plasma treatment.
A unique mechanism responsible for enhancing the autohesive tack strength of ethylene propylene diene rubber (EPDM) was elucidated by studying the interfacial strength of an unvulcanized EPDM elastomer joint in the presence of nanoclay. The tack strength significantly increased with nanoclay concentration up to 4 parts per 100 grams of rubber (phr), beyond which it dropped. For example, the tack strength of 4 phr of the nanoclay-loaded sample was nearly 137% higher than that of neat EPDM rubber. The influence of nanoclay in the bond formation and the bond separation steps of the tack test was understood by analyzing various tack governing factors such as green strength, creep compliance, entanglement molecular weight, relaxation time, the self-diffusion coefficient, and the monomer friction coefficient (ζ0). Furthermore, the ability of EPDM rubber to undergo strain-induced crystallization (SIC) during straining (at the time of bond separation in the peel test experiment) in the presence of nanoclay was also investigated. When the clay concentration was 4 phr, there was a slight reduction in the extent of molecular diffusion at the tack junction due to the nanoclay reinforcement; however, the diffusion was sufficient enough to establish entanglements across the interface. Furthermore, the less diffused chains of the nanocomposite samples showed greater bond breaking resistance than the unfilled sample due to the higher ζ0 value owing to the nanoclay reinforcement. It was also observed that the presence of nanoclay reduced the amount of crystallinity in the unstrained state and hence favored diffusion of elastomer chains across the interface. In addition, the presence of nanoclay significantly increased the ability of the EPDM elastomer to crystallize due to the alignment of nanoclay during straining, thus providing greater bond breaking resistance to the diffused elastomer chains. At higher clay loading (>4 phr), the elastomer chains could not establish entanglements across the interface due to extremely slow diffusion and aggregated platelets on the rubber surface, and therefore the tack strength decreased.Keywords: autohesive tack; EPDM; nanoclay; reinforcement; rubber
Co-reporter:Ganesh C. Basak, Abhijit Bandyopadhyay, Anil K. Bhowmick
International Journal of Adhesion and Adhesives 2010 Volume 30(Issue 6) pp:489-499
Publication Date(Web):September 2010
DOI:10.1016/j.ijadhadh.2010.04.003
Peel adhesion behavior of unvulcanized EPDM containing different tackifiers co-cured with vulcanized EPDM surfaces has been investigated and is reported in this paper. This work has great technical significance, as it involves adhesion studies on vulcanized rubber surfaces especially using a rubber like EPDM that has poor adhesion. Two different resins namely hydrocarbon (HC) and coumaroneindene (CI) have been used as tackifiers in this study. Wide range of concentrations of the tackifiers starting from 2 to 32 wt% with respect to EPDM has been investigated. The joint between vulcanized EPDM and tackifier modified unvulcanized EPDM has been prepared through co-curing method. The 180° peel test shows that HC modified EPDM exhibits better joint strength than the CI blended samples. These results have been explained with the help of “single side interdiffusion” concept inherited from viscoelastic studies and surface characterization of the unvulcanized rubber–resin blends. The peel strength of vulcanized EPDM co-cured with tackifier containing unvulcanized EPDM depends not only on compatibility but also on viscoelstic properties. A maximum of 138% improvement in peel strength value has been observed for HC containing system, while CI containing systems show only 27% improvement.
A series of novel in situ polydimethylsiloxane (PDMS)-sepiolite nanocomposites were synthesized by anionic ring opening polymerization of octamethylcyclotetrasiloxane. These nanocomposites were characterized by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy, Wide Angle X-Ray Diffraction (WAXD), Transmission Electron Microscopy (TEM), mechanical and dynamic mechanical properties and thermogravimetry. This paper highlights the structure-property relationship of in situ PDMS-sepiolite nanocomposites and a way to improve the mechanical, dynamic mechanical and thermal properties of silicone rubber. Comparison of these physico-mechanical properties with those of the ex situ nanocomposites reflects greater degree of filler dispersion for the in situ nanocomposites. Increasing amount of the filler reduced the size of the crystalline domains in PDMS matrix, which was evident from the X-Ray and the dynamic mechanical analysis. However, the polymer-filler interaction was even more prominent to negate the effect of the deterioration of the properties due to decrease in size of the microcrystallites. The polymer-filler interaction was reflected in the improved mechanical and thermal properties which were the consequences of proper dispersion of the filler in the polymer matrix. The modulus improvement of the rubber-clay nanocomposites was examined by using Guth and Halpin-Tsai model. The temperature of maximum degradation was raised by 167 °C and improvement of 210% in tensile strength and 460% in modulus at 100% elongation was observed. These results were correlated with the data obtained from WAXD and TEM studies.
Tribological characteristics of natural rubber nanocomposites for wear resistant applications have been studied by sliding against a steel blade, in a specially designed abrader. Testing parameters have been optimized for minimum wear based on Taguchi orthogonal design with four important parameters, viz., nanofiller loading, applied normal load, speed and time of run. Amongst these, nanofiller loading has the most significant influence on wear characteristics. In spite of the high normal pressure acting at the line of contact, certain well established power law relations are found to obey in principle, as wear increases with normal load and frictional work, Fw. Analysis of the micrographs of the abraded surface and the corresponding debris reveals that the specific wear rate of both the nanocomposites (sepiolite and carbon nanofiber filled) is found to increase beyond a critical fractal dimension, i.e., with increasing structural complexity of the debris formed. The rate of wear decreases steeply with nanofiber loading as compared to sepiolite. The changes in temperature build up and dynamic coefficients of friction are found to be concomitant. The wear mechanism is found to be fatigue at low frictional work, followed by frictional wear at high Fw.
Co-reporter:Pradip K. Maji, Nisith K. Das, Anil K. Bhowmick
Polymer 2010 Volume 51(Issue 5) pp:1100-1110
Publication Date(Web):2 March 2010
DOI:10.1016/j.polymer.2009.12.040
The helium gas permeation through polyurethanes (PU) having novel microstructures derived from different polyols (varying from linear to hyperbranched) in the presence and absence of modified and unmodified nanoclays has been studied thoroughly in this paper. The permeation rate of helium gas decreases from linear to fourth generation polyols (PU40) by about 80% due to increase in the crosslinking density. Similarly, the permeation rate of 8 wt% clay filled third generation hyperbranched PU dramatically decreases by about 76% in comparison to the unfilled PU. Gas-impermeable clay platelets in the PU matrix form tortuous pathways that further retard the progress of gas molecules. In addition, the well dispersed modified nanoclays contribute to improvement of the permeability properties to a great extent when compared with the aggregated unmodified ones. Further, interaction between the clays and the PU matrix plays a great role. Good correlation between dispersion of nanoclays in the PU matrix, as characterized by high resolution transmission electron microscopy and atomic force microscopy, and barrier resistance has been established. The permeation results have been compared with the different contemporary permeability models. The results are in line with the prediction by the Gusev-Lusti, the Nielsen and the Cussler (regular array) models at lower concentration of clay.
Adhesion between two unvulcanized rubber surfaces of the same material is termed autohesive tack. Interdiffusion of polymer chains that takes place across the interface and their bulk properties controls the strength of the interface. In this work, for the first time, we have studied the influence of sepiolite nanoclay on the autohesive tack strength of brominated isobutylene-co-p-methylstyrene (BIMS) rubber. The tack strength of BIMS rubber dramatically increases with nanoclay concentration. For example, the tack strength of 8 phr of nanoclay loaded sample is nearly 300% higher than the tack strength of neat BIMS rubber. Various tack governing factors such as green strength, creep compliance, entanglement molecular weight, relaxation times, self-diffusion coefficient, average penetration depth of rubber chains, and monomer friction coefficient have been analyzed. The addition of nanoclay reduces the extent of molecular diffusion across the interface by reducing the chain mobility; however, the diffusion level is still sufficient to form entanglements on either side of the interface. The entanglements arising from the diffused chains of the nanocomposite samples show greater resistance to separation due to an increase in cohesive strength, onset of transition zone relaxation time, and monomer friction coefficient value of the BIMS rubber matrix by the nanoclay reinforcement. On the other hand, the diffused chains of the unfilled sample exhibit facile chain separation due to the less cohesive strength of the BIMS rubber matrix.
Co-reporter:Titash Mondal, Anil K. Bhowmick and Ramanan Krishnamoorti
Journal of Materials Chemistry A 2013 - vol. 1(Issue 28) pp:NaN8153-8153
Publication Date(Web):2013/05/07
DOI:10.1039/C3TA11212H
Two effects of an organolithium reagent (n-butyl lithium) on graphene and expanded graphite are reported. Its ability to simultaneously scavenge protons and act as a nucleophile leads to a bi-functionalized graphitic system. Subsequent treatment with carbon dioxide gas generates carboxylic functionality at the proton abstraction sites. This technique promises a greener method for single pot carboxylation for graphitic materials. The nucleophilicity of n-butyl lithium leads to efficient grafting of butyl groups. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis are used to prove the success of the reaction. Raman spectroscopy reveals more defect sites for expanded graphite compared to graphene, which leads to a higher degree of functionalization. Atomic force microscopy shows that the functional groups generated are nano-spike-shaped pendant structures attached to the graphene. These functionalized materials are used as adsorbers for efficient and fast removal of water-soluble dyes by non-covalent interaction between the dye and the carboxylic groups of the graphitic system. Spectrometric as well as kinetic studies are reported for crystal violet lactone dye adsorption. Both the modified materials show twice the adsorption capacity of the pristine materials. Superior dye adsorption properties were observed for the modified materials compared to graphene oxide.
Co-reporter:Titash Mondal, Anil K. Bhowmick and Ramanan Krishnamoorti
Journal of Materials Chemistry A 2012 - vol. 22(Issue 42) pp:NaN22487-22487
Publication Date(Web):2012/09/25
DOI:10.1039/C2JM33398H
Facile synthesis of a chlorophenyl decorated graphene (CBG) sheet synthesized by a solvent free green diazotization technique is reported here. The functionalization of the material was supported by various characterization techniques including Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and thermal analysis. About 15 percent grafting, as determined by XPS and IR spectroscopy, could be achieved under the conditions employed. The CBG sheet was applied for the first time as a potential antibacterial agent on Gram negative bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus. The antibacterial character was quantified using the MacFarland number technique whereby the volumetric number density of colony forming units was determined. It was also quantified by a Kirby–Bauer test, where the zone formed due to mortality of bacteria caused by chlorine groups attached to the graphene was estimated by a mathematical model. Based on the zone of inhibition created, CBG was found to be more than twice as effective as unmodified graphene and graphene oxide. The synthesis promises to open up a new avenue for the development of chemically converted graphene based antimicrobial agents.
Co-reporter:Radhika Mehta, Rina Kumari, Prolay Das and Anil K. Bhowmick
Journal of Materials Chemistry A 2014 - vol. 2(Issue 37) pp:NaN6248-6248
Publication Date(Web):2014/07/24
DOI:10.1039/C4TB00854E
A novel tyrosine-based copolymer containing L-tyrosine (Tyr) and diglycidylether of bisphenol A(DGEBA) was synthesized and studied for its interaction with DNA for potential applications in biological systems. The synthesis of the polymer was optimized by varying monomer ratios using 4-(dimethylamino)pyridine (DMAP) as a catalyst to yield polymers with a Mw of 7500–8000. Further characterization by FTIR, NMR and thermal analysis supported the formation of the monotyrosine–DGEBA polymer. The interaction of the 1:1 DGEBA–tyrosine copolymer with DNA was investigated by gel electrophoresis, thermal melting, and fluorescence spectroscopy in ratios ranging from 0.5:1 to 12:1 polymer–DNA (w/w). The copolymer was seen to lend stability to the DNA without damaging it and demonstrated endonuclease resistivity that is conducive for biological applications. Scanning electron microscopy, dynamic light scattering and zeta potential studies of the polymer–DNA complex also established that the polymer is capable of encapsulating DNA leading to the formation of the DNA–polymer polyplex nano-assembly. The potential of the polymer for biological applications was further reinstated by its non-cytotoxicity.
