Evolved Gas Analysis-mass Spectrometry Research Articles

Material Characterization of Silicones for Additive Manufacturing.

Three-dimensional printing is ideally suited to produce unique and complex shapes. In this study, the material properties of polysiloxanes, commonly named silicones, produced additively by two different methods, namely, multi-jet fusion (MJF) and material extrusion (ME) with liquid printing heads, are investigated. The chemical composition was compared via Fourier-transform infrared spectroscopy, evolved gas analysis mass spectrometry, pyrolysis gas chromatography coupled to mass spectrometry, and thermogravimetry (TGA). Density and low-temperature flexibility, mechanical properties and crosslink distance via freezing point depression were measured before and after post-treatment at elevated temperatures. The results show significant differences in the chemical composition, material properties, as well as surface quality of the tested products produced by the two manufacturing routes. Chemical analysis indicates that the investigated MJF materials contain acrylate moieties, possibly isobornyl acrylate linking branches. The hardness of the MJF samples is associated with crosslinking density. In the ashes after TGA, traces of phosphorus were found, which could originate from initiators or catalysts of the curing process. The ME materials contain fillers, most probably silica, that differ in their amount. It is possible that silica also plays a role in the processing to stabilize the extrusion strand. For the harder material, a higher crosslink density was found, which was supported also by the other tested properties. The MJF samples have smooth surfaces, while the ME samples show grooved surface structures typical for the material extrusion process. Post-treatment did not improve the material properties. In the MJF samples, significant color changes were observed.

Selective recovery of pyrolyzates of biodegradable (PLA, PHBH) and common plastics (HDPE, PP, PS) during co-pyrolysis under slow heating

Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis–gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273–378 °C) than HDPE, PP, and PS (386–499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics.

Impact of Climate on Soil Organic Matter Composition in Soils of Tropical Volcanic Regions Revealed by EGA-MS and Py-GC/MS.

Soil organic matter (SOM) crucially influences the global carbon cycle, yet its molecular composition and determinants are understudied, especially for tropical volcanic regions. We investigated how SOM compounds change in response to climate, vegetation, soil horizon, and soil properties and the relationship between SOM composition and microbial decomposability in Tanzanian and Indonesian volcanic regions. We collected topsoil (0-15 cm) and subsoil (20-40 cm) horizons (n = 22; pH: 4.6-7.6; SOC: 10-152 g kg-1) with undisturbed vegetation and wide mean annual temperature and moisture ranges (14-26 °C; 800-3300 mm) across four elevational transects (340-2210 m asl.). Evolved gas analysis-mass spectrometry (EGA-MS) documented a simultaneous release of SOM compounds and clay mineral dehydroxylation. Subsequently applying double-shot pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) at 200 and 550 °C, we detailed the molecular composition of topsoil and subsoil SOM. A minor portion (2.7 ± 1.9%) of compounds desorbed at 200 °C, limiting its efficacy for investigating overall SOM characteristics. Pyrolyzed SOM closely aligns with the intermediate decomposable SOM pool, with most pyrolysates (550 °C) originating from this pool. Pyrolysates composition suggests tropical SOM is mainly microbial-derived and subsoil contains more degraded compounds. Higher litter inputs and attenuated SOM decomposition due to cooler temperatures and lower soil pH (<5.5) produce less-degraded SOM at higher elevations. Redundancy analyses revealed the crucial role of active Al/Fe (oxalate-extractable Al/Fe), abundant in low-temperature/high-moisture conditions, in stabilizing these less-degraded components. Our findings provide new insights into SOM molecular composition and its determinants, critical for understanding the carbon cycle in tropical ecosystems.

Additive manufacturing of wet-spun chitosan/hyaluronic acid scaffolds for biomedical applications

Additive manufacturing (AM) holds great potential for processing natural polymer hydrogels into 3D scaffolds exploitable for tissue engineering and in vitro tissue modelling. The aim of this research activity was to assess the suitability of computer-aided wet-spinning (CAWS) for AM of hyaluronic acid (HA)/chitosan (Cs) polyelectrolyte complex (PEC) hydrogels. A post-printing treatment based on HA chemical cross-linking via transesterification with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was investigated to enhance the structural stability of the developed scaffolds in physiological conditions. PEC formation and the esterification reaction were investigated by infrared spectroscopy, thermogravimetric analysis, evolved gas analysis-mass spectrometry, and differential scanning calorimetry measurements. In addition, variation of PMVEMA concentration in the cross-linking medium was demonstrated to strongly influence scaffold water uptake and its stability in phosphate buffer saline at 37 °C. The in vitro cytocompatibility of the developed hydrogels was demonstrated by employing the murine embryo fibroblast Balb/3T3 clone A31 cell line, highlighting that PMVEMA cross-linking improved scaffold cell colonization. The results achieved demonstrated that the developed hydrogels represent suitable 3D scaffolds for long term cell culture experiments.

Long-lasting flavor compounds of myrtle and immortelle from ancient Egyptian tombs: A study by analytical pyrolysis

In this work, an approach based on evolved gas analysis-mass spectrometry and double-shot analytical pyrolysis-gas chromatography-mass spectrometry was employed to investigate the low and high molecular weight fractions of two aromatic plants, myrtle and immortelle. The method was used to investigate myrtle and immortelle plants from historical herbaria, as well as archaeological samples from garlands found in ancient Egyptian tombs. Analytical pyrolysis allowed us to characterize both the volatile and non-volatile fractions, by sequentially performing a thermal desorption step and a pyrolysis step on the same sample. Volatile components ascribable to the flavor of myrtle and immortelle were detected in the first-shot chromatograms of all samples. These compounds included mono/sesquiterpenoids such as pinene and eucalyptol, and small phenols such as catechol and syringol. The results show that a portion of the volatile compounds of these plants can remain trapped in the lignocellulosic matrix for long times, and that double-shot Py-GC/MS can provide information on the volatile fraction of even archaeological plant samples.

Low- and high-molecular weight fractions of geological ambers detected by evolved gas analysis-mass spectrometry

We used evolved gas analysis-mass spectrometry (EGA-MS) to characterize a pool of ambers belonging to different geological varieties, with the aim of obtaining information on both their non-polymeric and polymeric components. Small molecular components can be trapped in amber during the fossilization process. Their characterization can provide insights into the maturation process of amber and help in determining its age and botanical origin. Most of the analyzed ambers showed two gas evolution regions, corresponding to the desorption of low-molecular weight compounds at low temperature, and to the pyrolysis of the macromolecular matrix at high temperature. We established characteristic m/z signals of the non-polymeric and polymeric fractions, and we were able to classify most of the samples in agreement with the available literature. We also performed principal component analysis of diterpenoid ambers using their average mass spectra. This allowed us to differentiate between succinite and rumanite ambers, which showed very similar spectra. The results demonstrate that EGA-MS constitutes a reliable technique to obtain information on the molecular composition of ambers, and on their relative content of low- and high-molecular weight fractions.

Preserving the Ephemeral: A Micro-Invasive Study on a Set of Polyurethane Scenic Objects from the 1960s and 1970s.

Among the innovative materials used by 20th-century artists, polyurethane (PUR) has been shown to be highly unstable, and therefore artworks made of it are now in need of careful conservation strategies. This study presents a multi-analytical investigation of PUR foam scenic objects originally made between the 1960s and 1970s during the Italian Arte Viva movement. The main components in the foam and additives were characterized through micro attenuated total reflectance infrared spectroscopy (μ-ATR-FTIR) and pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS). Painted samples were further investigated through μ-FTIR and Raman spectroscopy to define binders and pigments. The use of μ-ATR-FTIR in combination with evolved gas analysis-mass spectrometry (EGA-MS) allowed the variable conditions of the artworks to be assessed and attained some insights into the chemical processes responsible for aging. At the same time, morphological changes due to the degradation phenomena were recorded through optical (OM) and scanning electron microscopy (SEM). The detailed characterization of the PUR foam and painting materials was helpful in attaining some insights into harmful environmental parameters for the artworks, thus informing preventive conservation.

Network Degradation Assessed by Evolved Gas Analysis–Mass Spectrometry Combined with Principal Component Analysis (EGA–MS–PCA): A Case of Thermo-Oxidized Epoxy/Amine Network

To study the degradation of thermosetting polymers, we apply a novel method to simultaneously study the chemical structural changes and network topology: evolved gas analysis–mass spectrometry combined with principal component analysis (EGA–MS–PCA). This technique was applied to thermo-oxidative aging of an epoxy/amine network. The signals of various pyrolyzates remain overlapped in the complicated EGA–MS profiles. The key fragments of thermally evolved gases derived from the components of the network are effectively selected by PCA from the complicated EGA–MS profiles. EGA–MS–PCA provides information on the network structure: (i) the oxidized fraction of cross-links (i.e., chemically damaged cross-links), (ii) the relative quantification of unbonded chains, and (iii) the formation of dangling chains. The proposed technique can simultaneously characterize chemical degradation and network structural properties. This characterization technique can be utilized as a generally applicable tool for determining the structural durability of thermosetting polymers.

Pyrolysis mechanism of aliphatic amines bound to titania nanoparticles after H2O2 oxidation

Organic compounds bound to peroxotitanates can influence the photocatalytic activity of TiO2 nanoparticles (NPs) obtained by subsequent annealing. Knowledge of how this influence plays out is fundamental for the development of NPs with desirable catalytic behavior, which can be used for several applications. Thermoanalytical techniques can be used to simulate the annealing process on a small scale, but there is a lack of literature on this topic. This is especially true for nitrogen-containing organic compounds, which are not often used as organic modifiers in NP synthesis. Here, we present a multianalytical study of the pyrolytic behavior of the organic fraction of amine-functionalized titania NPs after peroxide treatment (namely peroxotitanate nanoparticles modified with aliphatic amines). The study was carried out by TGA-MS, evolved gas analysis-mass spectrometry (EGA-MS) and double-shot analytical pyrolysis-GC-MS. The most abundant peaks in the GC-MS profiles obtained after thermal desorption were ascribed to nitriles, unsaturated hydrocarbons, and oxygenated compounds, whose total relative areas accounted for almost 100% for DPA and up to 70% for the other amines. This indicated that the presence of an N-Ti bond modulated the oxidating effect of hydrogen peroxide. Pyrolysis of the residual organic fraction on oxidized NPs underwent coupling reactions that led to the formation of aromatic species and, most interestingly, heteroaromatic compounds.

Evolved Gas Analysis-Mass Spectrometry of Polypropylene in Air Atmosphere Using High-resolution Time-of-Flight Mass Spectrometer

Evolved Gas Analysis-Mass Spectrometry of Polypropylene in Air Atmosphere Using High-resolution Time-of-Flight Mass Spectrometer

A multi-analytical approach for precise identification of alkyd spray paints and for a better understanding of their ageing behaviour in graffiti and urban artworks

Contemporary graffiti and murals became an artistic expression worthy of attention worldwide as well as their conservation. The application of spray paints with increasing technical performance mirrors the variety of the chemical composition of these increasingly common painting materials. An insight into the formulation and the ageing process is extremely important to predict and prevent the possible decay phenomena observed on outdoor urban artworks. This paper aims to investigate the relationship between the macroscopic outcomes and the chemical changes occurring on spray paints after the ageing by a multi-analytical approach. A systematic artificial ageing procedure was performed on multiple sets of concrete mock-ups painted with three different alkyd-based spray paints and in three different light-sensitive colours. The colour variation was assessed by colorimetric measurements, the changes in the paint cross section were observed by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) was applied both to characterize the spray paints and to detect the chemical changes of the organic compounds during the ageing. A significant and innovative contribution to this research is the application of the evolved gas analysis-mass spectrometry (EGA-MS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) with tetramethylammonium hydroxide in double-shot mode. These two analytical methodologies allowed an accurate classification of the different alkyd-based binders, the identification of plasticizers, organic pigments and other components often hard to spot in complex formulations, and an analysis of their fate following ageing.

Product specific thermal degradation kinetics of bisphenol F epoxy in inert and oxidative atmospheres using evolved gas analysis–mass spectrometry

Knowledge of the degradation kinetics for polymer materials is important for understanding thermal stability. Here, evolved gas analysis–mass spectrometry and pyrolysis gas-chromatography-mass spectrometry were evaluated for the potential to deliver additional insight into thermal degradation kinetics of diglycidal ether of bisphenol F (DGEBF) epoxy thermoset under inert and oxidative atmospheres. Degradation products of selected precursor ions were evaluated for their uniqueness to the specific precursor using extracted ion thermographs. Unique mass peaks, solely attributed to a single reaction pathway of a specific product, were determined from extracted ion thermographs and used to determine both activation energy (Ea) and pre-exponential factors for the specific primary reaction pathways. These primary reaction pathways for DGEBF epoxy degradation were then evaluated in the context of transition state theory (TST) and related transition state enthalpies (ΔH‡) and entropies (ΔS‡) of activation to further elucidate the degradation process. It was determined under pyrolysis conditions, as suggested by the Ea, the formation of bisphenol F monomer was the rate-limiting step toward the formation of xanthene and phenol. In contrast, under thermo-oxidative conditions, reactions involving oxygen containing species were identified as the rate-limiting step for all observed products based on the large negative ΔS‡ calculated from TST. This work demonstrates a powerful combination of technique and theory that can provide new insight into the degradation of polymer materials.

Synthesis of Decorated Carbon Structures with Encapsulated Components by Low-Voltage Electric Discharge Treatment

Polycondensation of complexes of chloromethanes with triphenylphosphine by the action of low-voltage electric discharges in the liquid phase gives nanosized solid products. The elemental composition involving the generation of element distribution maps (scanning electron microscopy–energy dispersive X‑ray spectroscopy mapping) and the component composition (by direct evolved gas analysis–mass spectrometry) of the solid products have been studied. The elemental and component compositions of the result-ing structures vary widely depending on the chlorine content in the substrate and on the amount of triphenylphosphine taken. Thermal desorption analysis revealed abnormal behavior of HCl and benzene present in the solid products. In thermal desorption spectra, these components appear at an uncharacteristically high temperature. The observed anomaly in the behavior of HCl is due to HCl binding into a complex of the solid anion {text{HCl}}_{2}^{ - } with triphenyl(chloromethyl)phosphonium chloride, which requires a relatively high temperature (up to 800 K) to decompose. The abnormal behavior of benzene is associated with its encapsulated state in nanostructures. The appearance of benzene begins at 650 K and continues up to temperatures above 1300 K.

Plastics in robots: a degradation study of a humanoid skin mask made of soft urethane elastomer

Understanding the degradation of plastic materials is a big challenge for curators, conservators and conservation scientists in museums worldwide aiming to preserve their collections due to the variety of formulations of synthetic polymers and pigments. The conservation of polyurethane (PUR) based objects is challenging because they can suffer from extensive degradation. Particularly PUR elastomers can degrade shortly after their production, as occurred to the mask of the Japanese robot SAYA, which within 8 years suffered from two large tears, discoloration and stickiness. This research aims at studying the degradation phenomena of the androids’ synthetic skin. Better knowledge of the chemical composition of the mask and the chemical and physical decay will contribute to planning a suitable stabilization treatment. Within a multi-analytical approach, colorimetric and microscopic investigations highlighted discolored areas, which showed further color changes within a five months monitoring campaign, confirming the instability of the material likely due to ongoing degradation. Raman microscopy allowed the identification of Pigment White 6 (titanium dioxide TiO2) in the anatase form, known to promote the photosensitivity of PUR substrates towards ultraviolet (UV) light. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy identified the PUR composition of the mask, the presence of phthalates as plasticizers and suggested the formation of quinone chromophores in the polymer structure as a result of photo-oxidation, possibly responsible for the mask yellowing. Evolved gas analysis-mass spectrometry (EGA-MS) and double-shot-gas chromatography/mass spectrometry (TD/Py–GC/MS) analyses support the characterization of the formulation of the mask as being made of methylene diphenyl diisocyanate (MDI) PUR ether elastomer. Plasticizers in high concentration, mainly diisononyl phthalate (DINP) and bis(2-ethylhexyl)phthalate (DEHP), and the UV stabilizer Tinuvin 328 were also detected. In addition, the presence of styrene-acrylonitrile (SAN) could also contribute to the mask’s chemical instability. More amount of UV stabilizer and phthalates were detected at the surface (contributing to its stickiness) than in the inner core. The degradation of the mask results from the light susceptibility of MDI PUR ether and SAN, as well as the higher photochemical activity of anatase. The mask was transferred on to a mannequin and placed in the storage area to prevent light exposure and photo-oxidation. As loose edges had to be stabilized, tests were conducted and adhesive stripes glued with a PUR dispersion were selected for keeping the head’s shape. The novelty of this study is the implementation of conservation science on the study of androids with PUR elastomeric components in robotic collections, which are becoming increasingly popular in technical museums, however still seldomly studied.

Thermal decomposition behavior of MnO2/Mg-Al layered double hydroxide after removal and recovery of acid gas

Acidic gases such as HCl, SO2, and NOx are compounds that are generated through the incineration of waste products. Hence, an efficient method of removing such gases is highly desired. In this study, we present a novel method for treatment of acidic gases by using an MnO2/Mg-Al layered double hydroxide (MnO2/Mg-Al LDH), which provides several advantages in removing NO when compared to other removal methods, in addition to enabling the removal of HCl and SO2. We tested the recovery of acidic gases using the dry process, which separates the adsorbed gases from the LDH and recovers them as gases again, allowing them to be reused, and the adsorbent to be regenerated. To achieve this, we analyzed the pyrolysis behavior of MnO2/Mg-Al LDH at different temperatures and with various acidic gases adsorbed, using thermogravimetry (TG) and evolved gas analysis-mass spectrometry (EGA-MS), and further studied the recovery of adsorbed acidic gases. For HCl, NO, and SO2, outlet concentrations of 4000, 1000, and 950 ppm, respectively, were achieved, with recovery rates above 99% for all three. Additionally, we identified that for removal of both HCl and NO, MnO2/Mg-Al LDH desorbed the acid gas and generated Mg-Al layered double oxide (Mg-Al LDO) as the LDH structure collapsed. Furthermore, for SO2 removal, MgAl2O4 and MgO were generated. Overall, we confirmed that acidic gases such as HCl, NO, and SO2, can be recovered with high efficiency and at a high concentration by using MnO2/Mg-Al LDH. This method of removal can have many potential applications.

Synergistic effects during co-pyrolysis of milled wood lignin and polyolefins at the gas phase and liquid/solid phase contacting modes

Co-pyrolysis of biomass and waste plastics is the preferred technology for enhancing the production of fuels and valuable chemicals. Here, we studied the co-pyrolysis of milled wood lignin (MWL) with polyethylene (PE) and polypropylene (PP) at various weight ratios by thermogravimetry (TG), evolved gas analysis–mass spectrometry (EGA–MS), and product recovery tests using a fixed-bed reactor. Two reaction modes, liquid/solid phase (LSP) and gas phase (GP) contacting modes, were applied to investigate the physical prevention of melted polymers on the interactions between the vapored intermediates. The TG results showed that the weight losses were slightly altered in the MWL/PE and the decomposition was delayed in MWL/PP blends, whereas the EGA-MS analysis indicated that more vaporized products from the blends were detected by MS. The fixed-bed experiments showed that the yield of liquid was largely enhanced by the higher proportion of PE or PP in the blends, primarily due to the formation of lower oligomeric hydrocarbons from polyolefins. The yields of gasoline and kerosene were significantly increased in the GP mode from the co-pyrolysis of MWL with PE and PP, respectively. These results suggest that the MWL pyrolysates could enhance the cracking of PE intermediates in the GP reaction mode, whereas the rearrangement reactions of PP intermediates may be inhibited in the LSP reaction mode, converting more wax products into liquid. This paper provides a better understanding of the detailed synergistic effects during biomass and plastics co-pyrolysis.

Disclosing the chemistry of oil curing by mass spectrometry using methyl linoleate as a model binder

The structure of the polymeric fraction in an oil painting is believed to be strongly connected to the stability of the paint layers over time, but its molecular characterisation is extremely difficult given the complex composition of a vegetable oil-based polymer.In this study we report the implementation of a methodological approach for the systematic mass spectrometric investigation of the molecular features of the products of oxidative degradation and cross-linking of oil paint layers upon curing. The approach is based on the use of methyl linoleate as a simplified model of an oil paint binder. Gas-chromatography coupled with mass spectrometry, solid phase microextraction gas chromatography mass spectrometry, flow injection electrospray mass spectrometry and evolved gas analysis mass spectrometry, are used to analyse the evolution of compounds produced over seven months of natural ageing, from the volatile products to the macromolecular and cross-linked fractions. The aim is to improve our fundamental molecular understanding of the curing process of oil paints, and to investigate the balance between oxidative degradation and cross-linking when specific binder-pigment combinations are in place.Model paint layers were prepared using lead white and ultramarine blue as pigments. These two pigments are known to produce paint layers with different stability over time. The use of methyl linoleate as model oil binder greatly simplifies the mass spectral features of the lipid paint fraction, enabling the detection of products of oxidation and cross-linking with a new high level of molecular detail. Data clearly show that crucial differences between paints containing the two pigments establish with time, which are mostly related to the cross-linked fraction.

Review on Evolved Gas Analysis Mass Spectrometry with Soft Photoionization for the Chemical Description of Petroleum, Petroleum-Derived Materials, and Alternative Feedstocks

Modern industry strongly relies on the molecular analysis of fossil petroleum and petroleum-derived materials. In the context of a circular economy and carbon neutrality, the chemical description o...

Co-pyrolysis of wood and plastic: Evaluation of synergistic effects and kinetic data by evolved gas analysis-mass spectrometry (EGA-MS)

Co-pyrolysis of biomass and plastics gives rise to synergistic effects that can improve the properties of the resulting bio-oil. In this paper, the co-pyrolysis of lignocellulose (softwoods and hardwoods) and plastic (polyethylene and polystyrene) mixtures at different ratios was investigated by evolved gas analysis-mass spectrometry (EGA-MS). Through the extraction of specific sets of m/z values, we were able to build component-specific thermograms representative of each component of the mixtures. Such thermograms were used to evaluate the presence of synergistic effects by the comparison with the theoretical thermograms. The shift of the peak temperatures and the differences between the integrated area of the two thermograms showed that both biomass and plastic influence the pyrolytic behaviour of the other component. Finally, the KAS model-free isoconversional method was used on component-specific thermograms to determine apparent activation energies of the biomass and plastic fractions.

Three-way evolved gas analysis-mass spectrometry combined with principal component analysis (EGA-MS-PCA) to probe interfacial states between matrix and filler in poly(styrene-b-butadiene-b-styrene) (SBS) nanocomposites

We have developed a three-way evolved gas analysis-mass spectrometry technique combined with principal component analysis (EGA-MS-PCA) to probe the interfacial state between matrix and filler in poly(styrene-b-butadiene-b-styrene) (SBS) nanocomposites containing graphene nanoplatelets (GNPs). Although the peaks arising from the polystyrene and polybutadiene components present in the system were readily captured, the different patterns of peak intensities, which vary according to the applied temperature and GNP content, make interpretation of the data difficult. The data sets are thus subjected to mathematical decomposition based on principal component analysis (PCA) to selectively derive essential information. The EGA-MS-PCA process reveals that the inclusion of GNPs essentially works to restrict the decomposition of the polystyrene component in the SBS sample, mostly indicating the formation of a π–π stacking interaction between the SBS and GNPs. This observation, in turn, provides in-depth understanding that is likely to lead to stiffness of SBS by incorporation of GNPs.