Figure 3 - uploaded by Wan Md Zin Wan Yunus
Content may be subject to copyright.
Fourier transform infrared (FTIR) spectra of PLA, PEG, PLA/PEG blend and PLA/PEG/xGnP nanocomposite. 

Fourier transform infrared (FTIR) spectra of PLA, PEG, PLA/PEG blend and PLA/PEG/xGnP nanocomposite. 

Source publication
Article
Full-text available
Graphene nanoplatelets (xGnP) were investigated as a novel nano-reinforcement filler in poly(lactic acid)(PLA)/poly(ethylene glycol)(PEG) blends by the melt blending method. PLA was first plasticized by PEG in order to improve its flexibility and thereby overcome its problem of brittleness. Then, xGnP was incorporated into the PLA/PEG blend. The pr...

Context in source publication

Context 1
... stronger, confirming the increased crystallization in PLA/PEG at high xGnP loadings. The XRD results demonstrate the crystalline structure of PLA is slightly increased by the incorporation of xGnP. Figure 3 shows FTIR spectra of pristine PLA, PEG, PLA/PEG blend and PLA/PEG nanocomposites. PLA shows characteristic stretching frequencies for C=O, –CH 3 asymmetric, –CH 3 symmetric, and C–O, at 1746, 2995, 2946 and 1080 cm − 1 , respectively. Bending frequencies for –CH 3 asymmetric and –CH 3 symmetric have been identified at 1452 and 1361 cm − 1 , respectively. Meanwhile, a broad peak was observed at 3446 cm − 1 for PEG, which corresponds to terminal hydroxyl group. PLA/PEG and PLA/PEG nanocomposite shows almost same absorption peaks as pristine PLA. This means that there is no new bond formed or strong chemical interaction occurring within the blend and ...

Similar publications

Article
Full-text available
This research was carried out to investigate the addition of grafted copolymers of maleic anhydride grafted-polylactic acid (PLA-g-MA) and maleic anhydride grafted-natural rubber (NR-g-MA) on the mechanical and thermal properties of polylactic acid/ liquid natural rubber (PLA/LNR) blends. Prior to blend preparation, the PLA-g-MA and NR-g-MA were th...
Article
Full-text available
Paddy Straw Powder (PSP) show potential as a new reinforcement based-natural fibre. A Haake internal mixer was used to incorporated paddy straw powder (PSP) into polylactic acid (PLA). Polylactic acid (PLA)/paddy straw powder biocomposite was prepared using constant rotor speed (60rpm) for 14minutes at 180∘C. The effects of paddy straw powder conte...
Conference Paper
Full-text available
To study the distribution of morphological structures like fillers (such as silica nanoparticles) and their agglomerates in polymer nanocomposites, image processing technique on 2D scanning electron microscopy (SEM) image of the polymer nanocomposites was used. A suitable algorithm was proposed to determine the threshold for binarization of the SEM...

Citations

... In addition, Figure S7 [48][49][50]. However, the md-PI tensile strength is good enough to assemble TENG devices with desirable durability. ...
Article
Full-text available
Renewable energy has received attention all around the world to deal with environmental pollution and energy crisis. Triboelectric nanogenerators (TENGs) has emerged as a promising way to transition to green energy. However, typical TENGs exhibit inferior output, low heat-resistance, and low durability. Polyimide is one of the most mechanically strong and thermally stable thermoplastics, and it could be used to overcome the drawbacks of TENGs. Thus, polyimide has become a promising building material for robust TENGs. Herein, we have rationally designed and created an efficient polyimide tribo-surface with customizable non-close packed microdome arrays (md-PI) to assemble TENGs (md-TENG) for harvesting windmill energy and vibration from engine even with hot air and high humidity surrounding. The md-TENG fabricated with md-PI and flat aluminum can generate an exceptional output power of 1.42 W∙m⁻². This is about 29 times higher than the output of a TENG using a normal flat PI. Additional FEM simulations are performed to analyze the relationship between the contact area and mechanical stresses on the md-PI. Moreover, the md-TENG possesses outstanding durability of over 16,000 cycles of contact-separation, and the device exhibits better outputs at elevated temperature. The newly developed md-TENG achieves excellent thermal stability and durability as well as superior electrical output, which are essential to expand the practical applications of TENG. To illustrate the strengths of md-TENG, we demonstrated a wireless communication self-powered IoT humidity sensor and a vibration TENG sensor at high ambient air temperature in the engine compartment of a car.
... Main peak band assignments to PLLA are stretching frequencies for -CH 3 asymmetric, -CH 3 symmetric, C=O, and C-O at 2995, 2946, 1746, and 1080 cm −1 , respectively. In addition, bending frequencies have been shown for -CH 3 asymmetric and -CH 3 symmetric at 1452 and 1361 cm −1 [25]. As shown in scheme 1, Utilizing PAMAM-G 2 in the spinning solution may cause a cleavage in the ester bond of PLLA due to aminolysis reaction [20]. ...
Article
Full-text available
Hybrid electrospun scaffolds based on poly (L-lactic acid) (PLLA) / poly (amidoamine) (PAMAM-G2) dendrimer / gemini surfactant were fabricated for the enhancement of synergistic antibacterial activities. The second generation of poly (amidoamine) (PAMAM-G2) and cationic gemini surfactant were utilized to functionalize the optimum electrospun scaffolds. The gelatination process was utilized to improve the wettability of PLLA scaffolds to extend cell attachment and cell proliferation. PLLA nanofibrous scaffolds were characterized by energy dispersion X-ray (EDX), Scanning electron microscopy (SEM) images, mechanical properties, water contact angle, Fourier transform infrared (FTIR) spectroscopy, zeta potential and antibacterial assessment. In vitro cell biocompatibility was evaluated by MTT assay and morphology of PC-12 cells cultured on hybrid nanofibrous scaffolds and gelatinized ones. The results indicated that the optimum scaffolds could successfully modify the characteristics of PLLA scaffolds leading to much more appropriate physical and chemical properties. In addition, gelatinized nanofibrous scaffolds reveal more wettability enhancing cell attachment and proliferation. Furthermore, using poly (amidoamine) (PAMAM-G2) and gemini surfactant reveals synergetic antibacterial activity due to the competition between both cationic groups of PAMAM and gemini surfactant. Finally, improved cell adhesion and cell viability on modified scaffolds were confirmed. These favorable properties give a chance for these scaffolds to be used in a wide variety of biomedical applications.
... Strong peak bands were observed between 1400 and 2000 cm −1 , representing proteins in the film, and some peaks could be attributed to stretching of amide groups (C = O and C-N) in protein and angular deformations N-H groups [24,38]. Furthermore, the peak observed between 1300 and 1400 cm −1 is due to asymmetric and symmetric deformations of -CH 3 [39]. The starch content was responsible for the bands located between 1000 and 1300 cm −1 , and similar peaks were found for all the films; however, they were slightly higher for MFCU and MFC. Warren et al. [40] reported that the bands between 900 and 1300 cm −1 were due to stretching and bending of C-O-H, and also due to the starch glycosidic linkages. ...
... Strong peak bands were observed between 1400 and 2000 cm −1 , representing proteins in the film, and some peaks could be attributed to stretching of amide groups (C = O and C-N) in protein and angular deformations N-H groups [24,38]. Furthermore, the peak observed between 1300 and 1400 cm −1 is due to asymmetric and symmetric deformations of -CH3 [39]. The starch content was responsible for the bands located between 1000 and 1300 cm −1 , and similar peaks were found for all the films; however, they were slightly higher for MFCU and MFC. Warren et al. [40] reported that the bands between 900 and 1300 cm −1 were due to stretching and bending of C-O-H, and also due to the starch glycosidic linkages. ...
Article
Full-text available
The present study was aimed to investigate the effects of sonication and clove oil incorporation on the improvement of physical, antioxidant, and antimicrobial properties and lipid oxidation inhibiting abilities of mung bean flour (MF)-based films. There were three groups of films tested (1) MF: mung bean flour alone, (2) MFC: MF incorporated with 2% clove oil (C), and (3) MFCU: MFC prepared with sonication (25 kHz, 100% amplitude, 10 min). Film thickness and bulk density showed slight differences, and moisture content, solubility, and water vapor permeability significantly differed between the formulations. Tensile strength, elongation at break, and Young’s modulus were highest for the MFCU films, followed by MFC and MF in rank order. Furthermore, the Fourier-transform infrared spectroscopy results also demonstrated that the clove oil and sonication treatment had improved the interconnections of the biopolymers, thus increasing the physical strength of the film. Phytochemicals in terms of total phenolics and total flavonoids were elevated in the MFCU films and contributed to stronger radical scavenging abilities (p < 0.05). MFC and MFCU films showed a strong antibacterial control of the Gram-positive Staphylococcus aureus (S. aureus) and also of the Gram-negative Campylobacter jejuni (C. jejuni). Overall, the lipid oxidation indicators Thiobarbituric acid reactive substances (TBARS, peroxide value, p-anisidine value, and totox value) showed significantly high inhibition, attributed to radical scavenging activities in the MFCU and MFC samples. The mung bean flour films incorporated with clove oil and prepared with sonication have good potential as packaging materials for food due to strong physical, antimicrobial, and antioxidant properties, as well as lipid oxidation inhibiting abilities.
... The results illustrate that the thermal property of the graphene-ink coated samples improved, which can be related to the inherent thermal properties of the GnPs. Generally, when nanoscale fillers such as GnPs are dispersed inside polymeric films, the gas solvability and diffusion coefficients of the films are principally affected by the geometry and concentration of the nanoscale fillers [74,75]. GnPs form a barrier against releasing of the compounds during or after decomposition [76,77]. ...
Article
Nowadays, manufacturing bio-based and biodegradable materials for electronic applications is a swiftly growing field. This approach can effectively tackle the future electronic waste problems. However, the preparation of such sustainable materials with high conductivity remains a challenging task. Moreover, in many cases, the use of noxious solvents may be unavoidable. This study shows the feasibility of an aqueous emulsion-based printable conductive ink to be used in the field of flexible electronic devices. The emulsion ink contains polylactic acid (PLA) as a binder and graphene nanoplatelets as a conductive filler. It shows an encouraging electrical conductivity of 34.5 S/m when spray-coated onto a cotton fabric. Moreover, the conductive composite fabrics were very stable in cyclic strain tests, suitable for wearable electronics. A hot pressing post-treatment of the printed composite fabrics improved the electrical conductivity by up to two times. Additionally, the coatings also enhanced the mechanical properties of the cotton fabrics by increasing the Young’s modulus values almost twice compared to pristine fabric. This eco-friendly composite ink can be used as strain sensors for transforming certain electronic components into biodegradable versions.
... The crystallization of perovskite film was studied by XRD with a Rigaku Smart Lab X-ray Diffractometer from 10 • to 40 • . [27,28]. Very tiny peaks at similar positions are also observed in perovskite film with PLA passivation, but the peak intensities are very weak, indicating a limited amount of PLA is in the perovskite films (Fig. 1a), since the perovskite films are scratched out from the substrates to obtain the corresponding powder for the FTIR measurement, leading to the PLA on the film surface is mixed into the perovskite powder. ...
Article
Full-text available
Perovskite solar cells (PSCs) have attracted a lot of attention in recent years due to their high efficiency. However, this recorded performance (25.5%) is still lower than the theoretical Shockley-Queisser limit due to the defects at the surface and interface of devices. One potential strategy is to passivate the films by polymers for the PSCs owing to the tunable properties of the polymers. Herein, we introduce polylactic acid (PLA) with CH3 and CO functional groups to passivate the interface between the perovskite and hole-transport layers. The FTIR results display the interaction of PLA and perovskite. The hole-only devices demonstrate decreased hole defect density in the PSCs by PLA passivation. Therefore, the PCE of the PSCs increases from 19.3% to 20.6%, and the Voc enhances from 1.07 V to 1.10 V as the device is treated by PLA passivation. Furthermore, PLA passivation improves the stability of the PSCs. The PSC with PLA passivation maintains ∼90% of the initial PCE value, whereas the control device only keeps ∼72% for 14 days. Besides, the PCE of the PSC with PLA passivation can maintain ∼73% of the original value, but the PCE of the control device decreases to ∼45% of the initial value under 60 ± 5% RH for 450 min.
... In the case of PEG we observed peaks at 2860 and 1050 cm −1 that respectively correspond to −CH stretching and −CO stretching of polyether groups. 45 The FT-IR spectrum of PEGDA is not shown here because of its similarity to PEG, as they possess the same polyether functional groups. All observed peaks in DMA and PEG were also found in the DPA binder, indicating that DPA retains the functional groups of the monomers after polymerization. ...
... The FTIR spectrum of the PEG-plasticized PLA clearly shows the characteristic absorption bands in the regions of 3350-3450 cm −1 , 2750-3000 cm −1 , and at 1645 cm −1 due to O-H bending and stretching vibration, C-H asymmetric stretching vibration, and C=O stretching of ester bonds, respectively. A broad band was observed at 3446 cm −1 for PEG, which corresponds to the terminal hydroxyl group [45]. There are many studies focused on variation in the structures and properties of the biomaterials containing PEG that underwent gamma irradiation [46]. ...
... This result is in accordance with those obtained by chemilumiscence method (see below). The literature data demonstrated that gamma irradiation leads to oxidation reactions inducing the formation of hydroxyl groups which can be present in hydroperoxides or alcohols [45]. As it was already mentioned, in the radiation processing of polysaccharides including CS, the degradation process occurs at room temperature [19] by the breakage of the glycosidic bonds (bands at 1130-1160 and 1155 cm −1 ) of polymers reducing molecular weight and viscosity. ...
Article
Full-text available
The irradiation of polymeric materials with ionizing radiation (γ-rays, X-rays, accelerated electrons, ion beams, etc.) may lead to disproportion, hydrogen abstraction, arrangements, degradation, and/or the formation of new bonds. The purpose of this paper is to evaluate the effect of gamma irradiation on some new poly(lactic acid) (PLA)-based blends and biocomposites, which is crucial when they are used for food packaging or medical purposes. The polymeric blends and biocomposites based on PLA and rosemary ethanolic extract (R) and poly(ethylene glycol) (PEG) (20 wt%) plasticized PLA, chitosan (CS) (3–6 wt%) and R (0.5 wt%) biocomposites were subjected to gamma irradiation treatment using three low γ-doses of 10, 20, and 30 kGy. The effect of irradiation was evaluated by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), thermogravimetry (TG), chemiluminescence method (CL), migration studies, and antibacterial activity tests. It was found that in comparison with neat PLA, the gamma irradiation in the oxidative conditions of the PLA-based blends and biocomposites, causes modifications in the structure, morphology, and thermal properties of the materials depending on irradiation dose and the presence of natural additives such as rosemary and chitosan. It was established that under a gamma-irradiation treatment with dose of 10–20 kGy, the PLA materials showed minor changes in structure and properties being suitable for application in packaging and in addition after irradiation with such doses their antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium is improved.
... The characteristic infrared bands of PLA show stretching frequencies for C=O, -CH 3 asymmetric and C-O, at 1749, 2998 and 1079 cm −1 , respectively. Moreover, bending frequencies for -CH 3 asymmetric and -CH 3 symmetric have been identified at 1452 and 1361 cm −1 , respectively [37]. In the spectra of Doxy-loaded membranes, at about 1749 cm −1 , the intensity of the main characteristic band of PLA increased when the amount of the Doxy in the membranes was increased too. ...
... The FTIR spectrum of Doxy shows characteristic bands between 3000 and 3500 cm −1 (νOH and νNH), and 1610 cm −1 (amide band I) and 1570 cm −1 (amide band II) [12,35,36]. Moreover, Doxy shows C=O and C=C stretches between 1700 and 1600 cm −1 [37]. The characteristic infrared bands of PLA show stretching frequencies for C=O, -CH3 asymmetric and C-O, at 1749, 2998 and 1079 cm −1 , respectively. ...
... The characteristic infrared bands of PLA show stretching frequencies for C=O, -CH3 asymmetric and C-O, at 1749, 2998 and 1079 cm −1 , respectively. Moreover, bending frequencies for -CH3 asymmetric and -CH3 symmetric have been identified at 1452 and 1361 cm −1 , respectively [37]. In the spectra of Doxy-loaded membranes, at about 1749 cm −1 , the intensity of the main characteristic band of PLA increased when the amount of the Doxy in the membranes was increased too. ...
Article
Full-text available
The present study aimed to prepare nanofibers by electrospinning in the system polylactic acid-hydroxyapatite-doxycycline (PLA-HAP-Doxy) to be used as a drug delivery vehicle. Two different routes were employed for the preparation of Doxy-containing nanofibers: Immobilization on the electrospun mat’s surface and encapsulation in the fiber structure. The nanofibers obtained by Doxy encapsulation were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) and differential thermal analyses (DTA) and scanning electron microscopy (SEM). The adsorption properties of pure PLA and PLA-HAP nanofibers were investigated for solutions with different Doxy concentrations (3, 7 and 12 wt%). Moreover, the desorption properties of the active substance were tested in two different fluids, simulated body fluid (SBF) and phosphate buffer solution (PBS), to evidence the drug release properties. In vitro drug release studies were performed and different drug release kinetics were assessed to confirm the use of these nanofiber materials as efficient drug delivery vehicles. The obtained results indicate that the PLA-HAP-Doxy is a promising system for biomedical applications, the samples with 3 and 7 wt% of Doxy-loaded PLA-HAP nanofibers prepared by physical adsorption are the most acceptable membranes to provide prolonged release in PBS/SBF rather than an immediate release of Doxy.
... The water contact angle of flat PVDF-co-HFP is nearly 76.7 ° whereas after the porous structure was formed, the water contact angle increased remarkably to 117.9 °. This indicated porosity is correlated with the electrical generation and energy storage of materials [25,26], which will be presented in the next section. On the other hand, mechanical property of the porous PVDF-co-HFP film is relatively satisfactory (see Table S1 in Supporting Information). ...
Article
Full-text available
Triboelectric nanogenerator (TENG), one of the latest and most effective technologies to harvest green energy in the industrialization and modernization era, converts mechanical energy to electricity through triboelectrification and electrostatic induction. Herein, highly porous poly(vinylidene fluoride-co-hexafluoropropylene) (PDVF-co-HFP) as a negatively charged tribomaterial was assembled with microdome-patterned chitosan as a positively charged surface to fabricate TENG and examine its mechanical and electrical properties. The results revealed that the porous PVDF-co-HFP-based TENG could generate a maximum instantaneous power of 3 mW and an open-circuit voltage of 200 V, which is 4 times higher than that made from flat PVDF-co-HFP and could light up 102 LEDs. The newly developed PVDF-co-HFP-based TENG achieves a great convergence between excellent flexibility, scalability, and superior electrical output, which has great application potential in wearable electronic devices.
... On the other hand, the FTIR spectra of AA/CS NPs, OX/CS NPs, and AA-OX/CS NPs showed all major peaks of AA, OX, and CS NPs with no remarkable shifts, suggesting the physical entrapment of the drug/s within the CS matrix [41]. The FTIR spectra of PEGylated CS NPs (Figure 2g) revealed two characteristic peaks at 1409 cm −1 (-CH bending) and 1100 cm −1 (C-O-C stretching) [42]. Additionally, one peak was detected at 2918 cm −1, which may be attributed to -CH 2 stretching vibration. ...
... The FTIR spectra of AA/PEG-CS NPs, OX/PEG-CS NPs, and AA-OX/PEG-CS NPs (Figure 2h-j) revealed the presence of all main AA, OX, and PEGylated CS NPs peaks implying physical entrapment of the drug/s inside the CS matrix. These findings are in the same line with previous studies that reported the fabrication of nanocarriers coated with PEG [42,43]. inside the CS matrix. ...
... inside the CS matrix. These findings are in the same line with previous studies that reported the fabrication of nanocarriers coated with PEG [42,43]. ...
Article
Full-text available
This study aims to design a pH-responsive dual-loaded nanosystem based on PEGylated chitosan nanoparticles loaded with ascorbic acid (AA) and oxaliplatin (OX) for the effective treatment of breast cancer. In this regard, non-PEGylated and PEGylated chitosan nanoparticles (CS NPs) loaded with either ascorbic acid (AA), oxaliplatin (OX), or dual-loaded with AA-OX were fabricated using the ionotropic gelation method. The hydrodynamic diameters of the fabricated AA/CS NPs, OX/CS NPs, and AA-OX/CS NPs were 157.20 ± 2.40, 188.10 ± 9.70, and 261.10 ± 9.19 nm, respectively. While the hydrodynamic diameters of the designed AA/PEG-CS NPs, OX/PEG-CS NPs, and AA-OX/PEG-CS NPs were 152.20 ± 2.40, 156.60 ± 4.82, and 176.00 ± 4.21 nm, respectively. The ζ-potential of the prepared nanoparticles demonstrated high positive surface charges of +22.02 ± 1.50, +22.58 ± 1.85 and +40.4 ± 2.71 mV for AA/CS NPs, OX/CS NPs, and AA-OX/CS NPs, respectively. The ζ-potential of the PEGylated CS NPs was reduced owing to the shielding of the positive charges by the PEG chains. Additionally, all the prepared nanoparticles exhibited high entrapment efficiencies (EE%) and spherical-shaped morphology. The chemical features of the prepared nanoparticles were investigated using Fourier transform infrared (FTIR) spectroscopy. Release studies showed the capability of the prepared non-PEGylated and PEGylated chitosan NPs to release their cargo in the acidic environment of cancer tissue (pH 5.5). Furthermore, the AA/CS NPs, AA/PEG-CS NPs, OX/CS NPs, OX/PEG-CS NPs, AA-OX/CS NPs and AA-OX/PEG-CS NPs exhibited remarkable cytotoxic activities against breast adenocarcinoma (MCF-7) cells with IC50 values of 44.87 ± 11.49, 23.3 ± 3.73, 23.88 ± 6.29, 17.98 ± 3.99, 18.69 ± 2.22, and 7.5 ± 0.69 µg/mL, respectively; as compared to free AA and OX (IC50 of 150.80 ± 26.50 and 147.70 ± 63.91 µg/mL, respectively). Additionally, treatment of MCF-7 cells with IC50 concentrations of AA, AA/CS NPs, AA/PEG-CS NPs, OX, OX/CS NPs, OX/PEG-CS NPs, AA-OX/CS NPs or AA-OX/PEG-CS NPs increased the percentages of early apoptotic cells to 5.28%, 9.53%, 11.20%, 5.27%, 13.80%, 8.43%, 2.32%, and 10.10%, respectively, and increased the percentages of late apoptotic cells to 0.98%, 0.37%, 2.41%, 2.06%, 0.97%, 9.66%, 56%, and 81.50%, respectively. These results clearly indicate that PEGylation enhances the apoptotic effect of AA and OX alone, in addition to potentiating the apoptotic effect of AA and OX when combined on MCF-7 cells. In conclusion, PEGylated chitosan nanoparticles encapsulating AA, OX, or AA and OX represent an effective formula for induction of apoptosis in MCF-7 cells.