Polymer-nanocomposites played a significant role in the field of polymer nanotechnology for different innovative/modern applications. The properties of polymer nanocomposites display totally unexpected nature in comparison to the polymeric matrix. This is because of the excellent capacities of the nano-sized fillers and the expanded surface area at the interface. The nanoparticles properties, for example, molecule size, molecule size circulation, scattering state, geometric shape and surface properties are the other notable components, which adjust the material properties of the nanocomposites.
To confine Graphene Oxide (GO) from agglomerating and restacking, functionalization of GO has been performed. The three fundamental classes of GO functionalization will be by organic sources, functionalization of macromolecules, and functionalization by nanoparticles (Nps)
Poly (vinyl Alcohol) (PVA) is a transparent hydrophilic polymer that has been generally utilized in industry for quite a while
In this study, PVA films were prepared using GO/ZnO hybrid nano filler by a solution casting method. The hybrid Nano filler with nano size was introduced by wet chemical synthesis route by using 20.74 nm ZnO nanoparticle in our lab and the properties were explored
Poly vinyl alcohol (PVA) (MW = 1, 25,000), AR grade from Merck India Ltd, India, GO-ZnO Hybrid nano fillers are synthesized in and the detailed procedure is explained in the experimental procedure and Distilled water is used for all experiments in the lab
The GO/ZnO hybrid nanocomposite was synthesized by simple wet chemical method. In this method, Graphene oxide was dispersed in ethanol (2:1 wt/ vol ratio) and the solution mixture was sonicated for 1 hr at room temperature. Afterward ZnC4H6O4.2H2O (0.880g) was dissolved in to the mixer. The pH of the solution was adjusted to 10 by adding 1M NaOH solution and stirred for 30 min. the mixture was refluxed at 140°c under inert atmosphere for 24 hrs. The prepared hybrid nanocomposites were centrifuged and washed with ethanol and distilled water for several times. Product was dried under vacuum oven for 6 hours to get fine powder of GO/ZnO hybrid nanocomposites
The solution casting system was utilized for the manufacture of PVA/GO-ZnO polymer nanocomposite films. 4% PVA solution was prepared by dissolving PVA in double distilled water (4 wt %) at 70–80° C. After that to the uniform solution of PVA, GO-ZnO nanoparticles were added at various proportions of 1, 3 and 5 wt %. The mixture was kept for blending around 24 h. Ultra sonicator was utilized with 10 Hz for 15-30 min to homogenize the mixture. The homogeneous solution was poured in polypropylene dishes and kept in hot air oven at 65-70°C for 24 hours for the formation of thin film. A fine nanocomposite polymer film was observed. The film was kept in desiccators for preservation for further studies.
The X-Ray Diffractometer (XRD) for the PVA and composite film structure of the PVA/GO-ZnO nanocomposite was done in a Bruker diffractometer (model 8600 USA) with Cu Ka radiation (k = 0.15406 nm). The voltage was set at 40 kV at a scanning rate of 2°/min from 10° to 80° (2θ) angles.
FTIR offers quantitative and subjective investigation of organic compounds. Fourier Transform Infrared Spectroscopy (FTIR) distinguishes chemical bonds in a compound by creating an infrared absorption range. FTIR spectra of pure PVA and distinctive nanocomposite films were acquired a spectrum in the range from 4000 to 550 cm-1.
Thermal properties of the PVA/GO-ZnO nanocomposite films were drawn by Perkin Elmer DSC/TGA instrument (model exstar Japan). The nanocomposite films were warmed from 30̊ to 650̊ C with warming pace of 10̊ C/min under N2 medium.
Optical analysis carried for all the samples by UV-1800 (Shimadzu-Japan) spectrophotometer. The mathematical relationship of Tauc was used to calculate the band gap energy (Eg) of PVA and PVA/GO-ZnO nanocomposite films.
A significant property of many materials is sheet resistance (or surface resistivity), quantifying the ability of charges to move across uniform thin films. The four-probe technique is the most appropriate method used for monitoring sheet resistance. In order to make electrical contact with the material, this technique involves using four equally spaced, co-linear probes known as a four-point probe
Where V is the potential difference in volts between internal probes, ‘I’ is the current through the outer pair of ampere probes and ‘S’ the Spacing between meter probes
XRD is a significant instrument for describing the delamination and scattering of GO-ZnO hybrid fillers in the nanocomposites.
Furthermore, the (1 0 1) diffraction peak of PVA crystals at 2θ = 19.48° is a very intense peak from the composites after adding the ZnO NPs and GO. However, its location drops to 19.2°, its strength drops, and the crystallisation peak broadens, indicating that there is some contact between the three compounds which is logical with Yang, Shuai, et al
Morphological images of PVA/GO–ZnO composites was analyzed by SEM.
The Thermal dependability of PVA/GO-ZnO nanocomposites can be dissected from TGA-DSC methods. The TGA thermograms of the readied PVA/GO-ZnO composite films are appeared in
The percentage of weight loss of and PVA/GO-ZnO hybrid nanocomposite films at various temperatures is given in
Sample code |
Percentage of weight loss at various temperature |
|||||||
100° C |
200° C |
300° C |
400° C |
500° C |
600° C |
Residue |
||
Pure PVA |
7.3 |
13.92 |
25.45 |
77.01 |
93.52 |
94.10 |
5.9 |
|
PVA/ GO-ZnO (1%) |
5.12 |
11.04 |
27.47 |
75.60 |
92.41 |
92.9 |
7.1 |
|
PVA/ GO-ZnO (3%) |
4.74 |
10.75 |
26.28 |
72.44 |
91.9 |
91.79 |
8.21 |
|
PVA/ GO-ZnO (5%) |
9.60 |
12.29 |
16.77 |
84.42 |
87.07 |
90.75 |
9.25 |
The DSC behavior of the PVA and PVA/GO-ZnO hybrid nanocomposite films are shown in
The homogeneity of composites and the solid interfacial interaction between the hybrid nano film and the polymer network supposed to have significant impact on the mechanical properties.
The subtle differences of the mechanical properties are tabulated in
Sample code |
Young's modulus (MPa) |
Elongation at break (%) |
Tensile strength (MPa) |
Pure PVA |
104.407 |
15.94 |
3.84 |
PVA/ GO-ZnO (1%) |
61.307 |
239.52 |
5.82 |
PVA/ GO-ZnO (3%) |
104.839 |
239.4 |
9.75 |
PVA/ GO-ZnO (5%) |
106.765 |
239.78 |
10.48 |
A change in the molecular structure of the polymer causes change within the optical band gap. The optical band gap information is accessible from the UV-Visible spectrum absorption edge of the PVA/GO-ZnO NP nanocomposite films, as shown in
|
|
Pure PVA |
4.51 |
PVA/ GO-ZnO (1%) |
4.32 |
PVA/ GO-ZnO (3%) |
4.26 |
PVA/ GO-ZnO (5%) |
4.24 |
Using a four-probe technique, the DC conductivity of PVA and PVA/GO-ZnO nanocomposites was studied at room temperature. The plot of GO-ZnO NPs electrical conductivity versus weight percent loading is shown in
After evaluating
|
|
PVA |
9.952×10-8 |
PVA/GO-ZnO (1%) |
5.983×10-7 |
PVA/GO-ZnO (3%) |
1.220×10-6 |
PVA/GO-ZnO (5%) |
2.895×10-6 |
The biopolymer PVA/GO-ZnO hybrid nanocomposites were effectively prepared by solution casting method. The XRD tests, SEM and Fourier transform infrared spectrometry confirmed the presence of GO-ZnO in PVA matrix. The Nano film basic investigation revealed that GO-ZnO hybrid nanoparticles were homogenously dispersed in the polymer bed with great interaction in polymer strings. Also, it was observed that by adding GO-ZnO hybrid Nano filler to the PVA polymer, the mechanical properties of nanocomposites were improved. Mechanical properties, for example, Tensile strength, Young's modulus and extension at break of PVA properties were upgraded with the loading of GO-ZnO. The tensile strength of PVA- GO-ZnO (5%) percent increases from 3.84 MPa to 10.48 MPa, and the Young's modulus increases from 104.407 to 106.765 MPa. The addition of Nano filler improves the polymer's elongation behavior, which ranges from 15.94 MPa for pure PVA polymer film to 239.52 MPa for 1% loading GO-ZnO hybrid filler. It is well understood from the results that the increase in the percentage of GO-ZnO with PVA is responsible for reinforcing and hardening of the PVA matrix. The thermal stability was confirmed through TGA and DSC analysis. At 600o C the % of weight loss is 94.10 and it decreases to 90.75 with the addition of 5% of nano particle. The DC conductivity studies of PVA polymer is 9.952×10-8 s cm-1 and is increased as 5.983×10-7 s cm-1 with 1% of nano particle loading and reaches the value 2.895×10-6 s cm-1 by the incorporation of 5% GO-ZnO nano particle. PVA/GO–ZnO can be regarded as prominent material combining the good conducting properties of graphene oxide and important properties of Zinc Oxide for potential applications in the diverse scientific applications. Graphene as a carbonaceous material has outstanding properties which make it attention-grabbing material. Graphene is conductive in nature and has enormous future role in almost all areas of material science such as paints, varnishes, plastics, foams, and inks, induction heaters, in the construction of materials (concrete, cements, etc.), metallurgical processes, energy storage materials, catalysts, biocompatible implants. ZnO as a cheap material can be used to improve the mechanical properties of polymer nanocomposites. Fabrication of ZnO as a UV protection system can make it or ZnO based nanocomposite a robust candidate especially in polymer industry. Addition of ZnO nanoparticles into polymers can expand mechanical, electrical and optical properties of polymers because of strong interfacial interaction among organic polymer and inorganic nanoparticles due to its small size, large specific area .Thus nanocomposites of this type can be widely used in coatings, plastics, rubbers and other useful applications. PVA/GO-ZnO based nanoparticles can be applied in construction of LEDs or optoelectronic devices. PVA/GO-ZnO based nanocomposites can also be utilized as biosensors development. Comprehensive study is required on PVA/GO-ZnO based nano materials for their further applications in divergent areas. The chief limitations of PVA/GO-ZnO nanocomposites are post-recovery challenges, reusability, and recyclability. Research is in progress to overcome such limitations.