Hossein Baniasadi - Academia.edu (original) (raw)
Papers by Hossein Baniasadi
International Journal of Polymeric Materials and Polymeric Biomaterials, 2015
Highly conductive polypyrrole/graphene (PYG) nanocomposite was synthesized with chemical oxidatio... more Highly conductive polypyrrole/graphene (PYG) nanocomposite was synthesized with chemical oxidation process via emulsion polymerization and used for the preparation of novel porous conductive gelatin/chitosan-based scaffolds. The effect of PYG loading on various properties of scaffolds was investigated. The obtained results indicated that by introducing PYG into the polymeric matrix, the porosity and swelling capacity decreased while electrical conductivity and Young's modulus demonstrated increasing trend. The in vitro biodegradation test revealed that pure gelatin/chitosan matrix lost 80% of its weight after six weeks in the presence of lysozyme whilst the biodegradation rate was significantly lower for the conductive scaffolds. Furthermore, Schwann cell attachment and proliferation were evaluated by MTT assay and SEM image and the results revealed significant cell biocompatibility of the conductive scaffold with low amount of PYG. The results confirmed the potential of gelatin...
Research Subject: One of the important methods in the treatment of skin wounds is the use of woun... more Research Subject: One of the important methods in the treatment of skin wounds is the use of wound dressings. Recently, the use of polymer-based wound dressings has become increasingly common. The use of natural polymers is very important in wound dressings. The aim of the present study is to design and manufacture a polyvinyl alcohol/ aloe vera wound dressing with the capability of healing skin wounds. Research Approach: The electrospinning method was applied to prepare the samples. Aloe vera gel was first extracted, purified, and powdered by freeze-drying. In all samples, the amount of polyvinyl alcohol and aloe vera powder was fixed at 8 wt.%. This value was selected empirically based on the quality of the produced fibers. Different samples including different amounts of polyvinyl alcohol and aloe vera were produced and their properties including morphology, tensile strength, swelling, degradability, and antimicrobial properties were investigat-
International Journal of Biological Macromolecules
Journal of Biomaterials Applications
In the present study, alginate/cartilage extracellular matrix (ECM)-based injectable hydrogel was... more In the present study, alginate/cartilage extracellular matrix (ECM)-based injectable hydrogel was developed incorporated with silk fibroin nanofibers (SFN) for cartilage tissue engineering. The in situ forming hydrogels were composed of different ionic crosslinked alginate concentrations with 1% w/v enzymatically crosslinked phenolized cartilage ECM, resulting in an interpenetrating polymer network (IPN). The response surface methodology (RSM) approach was applied to optimize IPN hydrogel's mechanical properties by varying alginate and SFN concentrations. The results demonstrated that upon increasing the alginate concentration, the compression modulus improved. The SFN concentration was optimized to reach a desired mechanical stiffness. Accordingly, the concentrations of alginate and SFN to have an optimum compression modulus in the hydrogel were found to be 1.685 and 1.724% w/v, respectively. The gelation time was found to be about 10 s for all the samples. Scanning electron mi...
Macromolecular Materials and Engineering
ACS Sustainable Chemistry & Engineering
We developed a 3D-printing process based on thermoset biocomposites termed Delayed Extrusion of C... more We developed a 3D-printing process based on thermoset biocomposites termed Delayed Extrusion of Cold Masterbatch (DECMA). DECMA is a processing method, based on controlling the degree of curing, that takes some responsibility of the 3D printing from materials and as such can be used to 3D print otherwise unprintable materials. First, a masterbatch was produced by mixing a bio-based resin (bioepoxy) and sawdust and lignin. This paste was partially cured at room temperature until reaching an apparent viscosity suitable for extrusion (≈10 5 mPa•s at 1 s −1). The system was next cooled (5−10°C) to delay subsequent hardening prior to 3D printing. The printability of the biocomposite paste was systematically investigated and the merits of the delayed extrusion, via DECMA, were assessed. It was found that DECMA allowed the revalorization of sawdust and lignin via 3D printing, as direct printing led to failed prints. Our approach afforded cost-effective, shearthinning dopes with a high bio-based content (58−71%). The bio-based 3D-printed materials demonstrated good machinability by computer numerical control (CNC). Overall, the benefits of the introduced DECMA method are shown for processing bio-based materials and for on-demand solidification during additive manufacturing.
Journal of Wound Care
Objective: Providing a suitable environment to improve the healing process is the main target of ... more Objective: Providing a suitable environment to improve the healing process is the main target of wound dressing that also protects the wound from additional harms. In the present study, fabrication and characterisation of a new kind of electrospun wound dressing composed of polyvinyl alcohol (PVA) and quince seed mucilage (QSM) is reported. Method: QSM was extracted from quince seeds, purified, freeze-dried and used to produce aqueous solutions containing different amounts of PVA and QSM. The wound dressings were fabricated via the electrospinning method and their characteristics were investigated with scanning electron microscope (SEM) images, Fourier transform infrared (FTIR) spectra, tensile and swelling test, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cytotoxicity assay against fibroblast cells. Results: SEM images confirmed that proper, uniform, non-oriented nanofibres with an average diameter in the range of 60–240nm, depending on the QSM conten...
Materials Science and Engineering: C
We proposed a simple method to process hydrogels containing polyvinyl alcohol and cellulose nanof... more We proposed a simple method to process hydrogels containing polyvinyl alcohol and cellulose nanofibrils (PVA/CNF) to prepare volumetric architectures by direct ink writing (DIW). The presence of CNF in the aqueous PVA suspensions conferred rheology profiles that were suitable for extrusion and solidification in pre-designed shapes. The viscoelastic behavior of the hybrid inks enabled precise control on processability and shape retention, for instance, as demonstrated in multilayered lattice structures of high fidelity. After lyophilization, the obtained 3D-printed hydrogels presented a very high porosity, with open and interconnected pores, allowing a high-water uptake capacity (up to 1600%). The mechanical strength of the composite 3D-printed materials matched those of soft tissues, opening opportunities for skin applications. As such, drug-loaded samples revealed a controlled and efficient delivery of an antioxidant (ascorbic acid) in PBS buffer media at 23 °C (~80% for 8 h). Altogether, PVA/CNF hydrogels were introduced as suitable precursors of 3D-lattice geometries with excellent physical and mechanical characteristics.
Composites Part B: Engineering
Polymer Engineering & Science
Materials Research Express
International Journal of Biological Macromolecules
In this study, we reported the design and fabrication of starch/gelatin/graphene oxide biodegrada... more In this study, we reported the design and fabrication of starch/gelatin/graphene oxide biodegradable nanocomposite films with proper potential for food packaging applications. The experiments were designed using Design Expert software via RSM by defining gelatin/starch weight ratio (G/S wt. ratio) and graphene oxide (GO) wt.% as process parameters affecting on the properties of the prepared films. The optimization was done and various properties of the optimum film were investigated. The XRD and SEM images confirmed that GO layers could intercalate in the starch/gelatin matrix and proper dispersion of nanofillers in the matrix obtained via solution casting method. The mechanical strength, thermal stability, surface hydrophilicity, and water vapor permeability were improved in the present of GO which could be related to reinforcing effect and proper barrier property of GO. Degradation of the prepared films under the soil was investigated during 6 weeks and the results indicated at least 30% weight loss happened throughout the test duration. Overall, the obtained results corroborate that the starch/gelatin/GO compounding can be a good candidate for fabricating of biodegradable nanocomposite films for food packaging applications.
Journal of Biomaterials Applications
Peripheral nervous system in contrary to central one has the potential for regeneration, but its ... more Peripheral nervous system in contrary to central one has the potential for regeneration, but its regrowth requires proper environmental conditions and supporting growth factors. The aim of this study is to design and fabricate a conductive polyaniline/graphene nanoparticles incorporated gelatin nanofibrous scaffolds suitable for peripheral nervous system regeneration. The scaffolds were fabricated with electrospinning and the fabrication process was designed with Design-Expert software via response surface methodology. The effect of process parameters including applied voltage (kV), syringe pump flow rate (cm3/h), and PAG concentration (wt%), on the scaffold conductivity, nanofibers diameter, and cell viability were investigated. The obtained results showed that the scaffold conductivity and cell viability are affected by polyaniline/graphene concentration while nanofiber diameter is more affected by the applied voltage and syringe pump flow rate. Optimum scaffold with maximum conduct...
Journal of biomaterials applications, Jan 24, 2016
In this study, we reported the preparation of self cross-linked oxidized alginate-gelatin hydroge... more In this study, we reported the preparation of self cross-linked oxidized alginate-gelatin hydrogels for muscle tissue engineering. The effect of oxidation degree (OD) and oxidized alginate/gelatin (OA/GEL) weight ratio were examined and the results showed that in the constant OA/GEL weight ratio, both cross-linking density and Young's modulus enhanced by increasing OD due to increment of aldehyde groups. Furthermore, the degradation rate was increased with increasing OD probably due to decrement in alginate molecular weight during oxidation reaction facilitated degradation of alginate chains. MTT cytotoxicity assays performed on Wharton's Jelly-derived umbilical cord mesenchymal stem cells cultured on hydrogels with OD of 30% showed that the highest rate of cell proliferation belong to hydrogel with OA/GEL weight ratio of 30/70. Overall, it can be concluded from all obtained results that the prepared hydrogel with OA/GEL weight ratio and OD of 30/70 and 30%, respectively, co...
International journal of biological macromolecules, Jan 29, 2016
Porous gelatin-chitosan microcarriers (MCs) with the size of 350±50μm were fabricated with blends... more Porous gelatin-chitosan microcarriers (MCs) with the size of 350±50μm were fabricated with blends of different gelatin/chitosan (G/C) weight ratio using an electrospraying technique. Response surface methodology (RSM) was used to study the quantitative influence of process parameters, including blend ratio, voltage, and syringe pump flow rate, on MCs diameter and density. In the following, MCs of the same diameter and different G/C weight ratio (1, 2, and 3) were fabricated and their porosity and biocompatibility were investigated via SEM images and MTT assay, respectively. The results showed that mesenchymal stem cells (MSCs) could attach, proliferate, and spread on fabricated porous MCs during 7 days of culturing especially on those prepared with a G/C weight ratio of 1. Such porous gelatin-chitosan MCs with a G/C weight ratio of 1 may be considered as a promising candidate for injectable carriers supporting attachment and proliferation of MSCs.
Polymer-Plastics Technology and Engineering, 2015
ABSTRACT Ethylene vinyl acetate (EVA)-based nanocomposites with 18 and 28 wt.% vinyl acetate were... more ABSTRACT Ethylene vinyl acetate (EVA)-based nanocomposites with 18 and 28 wt.% vinyl acetate were prepared via solution casting method. In order to improve the mechanical and barrier properties of EVA, linear low density polyethylene (LLDPE) and graphene oxide (GO) were introduced to matrix. The morphological studies indicated that the GO diffraction peak was disappeared in all prepared nanocomposites probably due to its exfoliation; also proper dispersion and good interaction between nanofillers and polymer matrix were achieved. By introducing low amount of GO into the matrix the mechanical and thermal properties, and oxygen permeability were improved especially for those with 28 wt.% vinyl acetate monomer.
Materials & Design, 2009
This paper is devoted to investigation of morphological and physical-mechanical properties of pol... more This paper is devoted to investigation of morphological and physical-mechanical properties of polyethylene (PE)/clay nanocomposites prepared via in situ polymerization method using bi-supported Ziegler-Natta catalyst. Bentonite type clay and MgCl 2 (ethoxide type) were used as the support of TiCl 4. Catalyst support and polymerization process have been done in slurry phase using Triisobutylaluminum as the cocatalyst. The microstructure of the nanocomposites was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM indicated that almost fully exfoliated PE/clay nanocomposites were produced successfully using this method. According to permeability measurements, it was found that oxygen permeability values of the nanocomposite samples prepared with in situ polymerization method were dropped more than 200% introducing only 1 wt% clay to polymeric matrix. Differential scanning calorimetry (DSC) results indicated that the crystallization temperatures of samples are significantly higher than that of virgin PE. Moderate thermal stability enhancement of in situ polymerized nanocomposites was confirmed using thermogravimetric analysis (TGA).The storage modulus, Young's modulus and tensile strength of prepared samples were increased where the toughness was declined slightly. It seems that good dispersion and exfoliation of clay during polymerization should be responsible to get more effective reinforcing properties for clay in this method comparing to melt blending method for preparation of polyethylene nanocomposites.
International Journal of Polymeric Materials and Polymeric Biomaterials, 2015
Highly conductive polypyrrole/graphene (PYG) nanocomposite was synthesized with chemical oxidatio... more Highly conductive polypyrrole/graphene (PYG) nanocomposite was synthesized with chemical oxidation process via emulsion polymerization and used for the preparation of novel porous conductive gelatin/chitosan-based scaffolds. The effect of PYG loading on various properties of scaffolds was investigated. The obtained results indicated that by introducing PYG into the polymeric matrix, the porosity and swelling capacity decreased while electrical conductivity and Young's modulus demonstrated increasing trend. The in vitro biodegradation test revealed that pure gelatin/chitosan matrix lost 80% of its weight after six weeks in the presence of lysozyme whilst the biodegradation rate was significantly lower for the conductive scaffolds. Furthermore, Schwann cell attachment and proliferation were evaluated by MTT assay and SEM image and the results revealed significant cell biocompatibility of the conductive scaffold with low amount of PYG. The results confirmed the potential of gelatin...
Research Subject: One of the important methods in the treatment of skin wounds is the use of woun... more Research Subject: One of the important methods in the treatment of skin wounds is the use of wound dressings. Recently, the use of polymer-based wound dressings has become increasingly common. The use of natural polymers is very important in wound dressings. The aim of the present study is to design and manufacture a polyvinyl alcohol/ aloe vera wound dressing with the capability of healing skin wounds. Research Approach: The electrospinning method was applied to prepare the samples. Aloe vera gel was first extracted, purified, and powdered by freeze-drying. In all samples, the amount of polyvinyl alcohol and aloe vera powder was fixed at 8 wt.%. This value was selected empirically based on the quality of the produced fibers. Different samples including different amounts of polyvinyl alcohol and aloe vera were produced and their properties including morphology, tensile strength, swelling, degradability, and antimicrobial properties were investigat-
International Journal of Biological Macromolecules
Journal of Biomaterials Applications
In the present study, alginate/cartilage extracellular matrix (ECM)-based injectable hydrogel was... more In the present study, alginate/cartilage extracellular matrix (ECM)-based injectable hydrogel was developed incorporated with silk fibroin nanofibers (SFN) for cartilage tissue engineering. The in situ forming hydrogels were composed of different ionic crosslinked alginate concentrations with 1% w/v enzymatically crosslinked phenolized cartilage ECM, resulting in an interpenetrating polymer network (IPN). The response surface methodology (RSM) approach was applied to optimize IPN hydrogel's mechanical properties by varying alginate and SFN concentrations. The results demonstrated that upon increasing the alginate concentration, the compression modulus improved. The SFN concentration was optimized to reach a desired mechanical stiffness. Accordingly, the concentrations of alginate and SFN to have an optimum compression modulus in the hydrogel were found to be 1.685 and 1.724% w/v, respectively. The gelation time was found to be about 10 s for all the samples. Scanning electron mi...
Macromolecular Materials and Engineering
ACS Sustainable Chemistry & Engineering
We developed a 3D-printing process based on thermoset biocomposites termed Delayed Extrusion of C... more We developed a 3D-printing process based on thermoset biocomposites termed Delayed Extrusion of Cold Masterbatch (DECMA). DECMA is a processing method, based on controlling the degree of curing, that takes some responsibility of the 3D printing from materials and as such can be used to 3D print otherwise unprintable materials. First, a masterbatch was produced by mixing a bio-based resin (bioepoxy) and sawdust and lignin. This paste was partially cured at room temperature until reaching an apparent viscosity suitable for extrusion (≈10 5 mPa•s at 1 s −1). The system was next cooled (5−10°C) to delay subsequent hardening prior to 3D printing. The printability of the biocomposite paste was systematically investigated and the merits of the delayed extrusion, via DECMA, were assessed. It was found that DECMA allowed the revalorization of sawdust and lignin via 3D printing, as direct printing led to failed prints. Our approach afforded cost-effective, shearthinning dopes with a high bio-based content (58−71%). The bio-based 3D-printed materials demonstrated good machinability by computer numerical control (CNC). Overall, the benefits of the introduced DECMA method are shown for processing bio-based materials and for on-demand solidification during additive manufacturing.
Journal of Wound Care
Objective: Providing a suitable environment to improve the healing process is the main target of ... more Objective: Providing a suitable environment to improve the healing process is the main target of wound dressing that also protects the wound from additional harms. In the present study, fabrication and characterisation of a new kind of electrospun wound dressing composed of polyvinyl alcohol (PVA) and quince seed mucilage (QSM) is reported. Method: QSM was extracted from quince seeds, purified, freeze-dried and used to produce aqueous solutions containing different amounts of PVA and QSM. The wound dressings were fabricated via the electrospinning method and their characteristics were investigated with scanning electron microscope (SEM) images, Fourier transform infrared (FTIR) spectra, tensile and swelling test, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) cytotoxicity assay against fibroblast cells. Results: SEM images confirmed that proper, uniform, non-oriented nanofibres with an average diameter in the range of 60–240nm, depending on the QSM conten...
Materials Science and Engineering: C
We proposed a simple method to process hydrogels containing polyvinyl alcohol and cellulose nanof... more We proposed a simple method to process hydrogels containing polyvinyl alcohol and cellulose nanofibrils (PVA/CNF) to prepare volumetric architectures by direct ink writing (DIW). The presence of CNF in the aqueous PVA suspensions conferred rheology profiles that were suitable for extrusion and solidification in pre-designed shapes. The viscoelastic behavior of the hybrid inks enabled precise control on processability and shape retention, for instance, as demonstrated in multilayered lattice structures of high fidelity. After lyophilization, the obtained 3D-printed hydrogels presented a very high porosity, with open and interconnected pores, allowing a high-water uptake capacity (up to 1600%). The mechanical strength of the composite 3D-printed materials matched those of soft tissues, opening opportunities for skin applications. As such, drug-loaded samples revealed a controlled and efficient delivery of an antioxidant (ascorbic acid) in PBS buffer media at 23 °C (~80% for 8 h). Altogether, PVA/CNF hydrogels were introduced as suitable precursors of 3D-lattice geometries with excellent physical and mechanical characteristics.
Composites Part B: Engineering
Polymer Engineering & Science
Materials Research Express
International Journal of Biological Macromolecules
In this study, we reported the design and fabrication of starch/gelatin/graphene oxide biodegrada... more In this study, we reported the design and fabrication of starch/gelatin/graphene oxide biodegradable nanocomposite films with proper potential for food packaging applications. The experiments were designed using Design Expert software via RSM by defining gelatin/starch weight ratio (G/S wt. ratio) and graphene oxide (GO) wt.% as process parameters affecting on the properties of the prepared films. The optimization was done and various properties of the optimum film were investigated. The XRD and SEM images confirmed that GO layers could intercalate in the starch/gelatin matrix and proper dispersion of nanofillers in the matrix obtained via solution casting method. The mechanical strength, thermal stability, surface hydrophilicity, and water vapor permeability were improved in the present of GO which could be related to reinforcing effect and proper barrier property of GO. Degradation of the prepared films under the soil was investigated during 6 weeks and the results indicated at least 30% weight loss happened throughout the test duration. Overall, the obtained results corroborate that the starch/gelatin/GO compounding can be a good candidate for fabricating of biodegradable nanocomposite films for food packaging applications.
Journal of Biomaterials Applications
Peripheral nervous system in contrary to central one has the potential for regeneration, but its ... more Peripheral nervous system in contrary to central one has the potential for regeneration, but its regrowth requires proper environmental conditions and supporting growth factors. The aim of this study is to design and fabricate a conductive polyaniline/graphene nanoparticles incorporated gelatin nanofibrous scaffolds suitable for peripheral nervous system regeneration. The scaffolds were fabricated with electrospinning and the fabrication process was designed with Design-Expert software via response surface methodology. The effect of process parameters including applied voltage (kV), syringe pump flow rate (cm3/h), and PAG concentration (wt%), on the scaffold conductivity, nanofibers diameter, and cell viability were investigated. The obtained results showed that the scaffold conductivity and cell viability are affected by polyaniline/graphene concentration while nanofiber diameter is more affected by the applied voltage and syringe pump flow rate. Optimum scaffold with maximum conduct...
Journal of biomaterials applications, Jan 24, 2016
In this study, we reported the preparation of self cross-linked oxidized alginate-gelatin hydroge... more In this study, we reported the preparation of self cross-linked oxidized alginate-gelatin hydrogels for muscle tissue engineering. The effect of oxidation degree (OD) and oxidized alginate/gelatin (OA/GEL) weight ratio were examined and the results showed that in the constant OA/GEL weight ratio, both cross-linking density and Young's modulus enhanced by increasing OD due to increment of aldehyde groups. Furthermore, the degradation rate was increased with increasing OD probably due to decrement in alginate molecular weight during oxidation reaction facilitated degradation of alginate chains. MTT cytotoxicity assays performed on Wharton's Jelly-derived umbilical cord mesenchymal stem cells cultured on hydrogels with OD of 30% showed that the highest rate of cell proliferation belong to hydrogel with OA/GEL weight ratio of 30/70. Overall, it can be concluded from all obtained results that the prepared hydrogel with OA/GEL weight ratio and OD of 30/70 and 30%, respectively, co...
International journal of biological macromolecules, Jan 29, 2016
Porous gelatin-chitosan microcarriers (MCs) with the size of 350±50μm were fabricated with blends... more Porous gelatin-chitosan microcarriers (MCs) with the size of 350±50μm were fabricated with blends of different gelatin/chitosan (G/C) weight ratio using an electrospraying technique. Response surface methodology (RSM) was used to study the quantitative influence of process parameters, including blend ratio, voltage, and syringe pump flow rate, on MCs diameter and density. In the following, MCs of the same diameter and different G/C weight ratio (1, 2, and 3) were fabricated and their porosity and biocompatibility were investigated via SEM images and MTT assay, respectively. The results showed that mesenchymal stem cells (MSCs) could attach, proliferate, and spread on fabricated porous MCs during 7 days of culturing especially on those prepared with a G/C weight ratio of 1. Such porous gelatin-chitosan MCs with a G/C weight ratio of 1 may be considered as a promising candidate for injectable carriers supporting attachment and proliferation of MSCs.
Polymer-Plastics Technology and Engineering, 2015
ABSTRACT Ethylene vinyl acetate (EVA)-based nanocomposites with 18 and 28 wt.% vinyl acetate were... more ABSTRACT Ethylene vinyl acetate (EVA)-based nanocomposites with 18 and 28 wt.% vinyl acetate were prepared via solution casting method. In order to improve the mechanical and barrier properties of EVA, linear low density polyethylene (LLDPE) and graphene oxide (GO) were introduced to matrix. The morphological studies indicated that the GO diffraction peak was disappeared in all prepared nanocomposites probably due to its exfoliation; also proper dispersion and good interaction between nanofillers and polymer matrix were achieved. By introducing low amount of GO into the matrix the mechanical and thermal properties, and oxygen permeability were improved especially for those with 28 wt.% vinyl acetate monomer.
Materials & Design, 2009
This paper is devoted to investigation of morphological and physical-mechanical properties of pol... more This paper is devoted to investigation of morphological and physical-mechanical properties of polyethylene (PE)/clay nanocomposites prepared via in situ polymerization method using bi-supported Ziegler-Natta catalyst. Bentonite type clay and MgCl 2 (ethoxide type) were used as the support of TiCl 4. Catalyst support and polymerization process have been done in slurry phase using Triisobutylaluminum as the cocatalyst. The microstructure of the nanocomposites was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD and TEM indicated that almost fully exfoliated PE/clay nanocomposites were produced successfully using this method. According to permeability measurements, it was found that oxygen permeability values of the nanocomposite samples prepared with in situ polymerization method were dropped more than 200% introducing only 1 wt% clay to polymeric matrix. Differential scanning calorimetry (DSC) results indicated that the crystallization temperatures of samples are significantly higher than that of virgin PE. Moderate thermal stability enhancement of in situ polymerized nanocomposites was confirmed using thermogravimetric analysis (TGA).The storage modulus, Young's modulus and tensile strength of prepared samples were increased where the toughness was declined slightly. It seems that good dispersion and exfoliation of clay during polymerization should be responsible to get more effective reinforcing properties for clay in this method comparing to melt blending method for preparation of polyethylene nanocomposites.