Preparation and interfacial properties of functionalised graphene oxide modified carbon fibre/epoxy resin matrix composites

Abstract

The interfacial properties of carbon fibre (CF) reinforced epoxy resin composites are the key factors affecting the mechanical properties of the materials. To improve the interfacial adhesion between CF and epoxy resin, an effective CF surface modification method is proposed in this paper. The surface of graphene oxide (GO) was functionalised with 3-aminopropyltriethoxysilane (APTES), and then the functionalised graphene oxide (FGO) was grafted on the surface of CF. The surface roughness of modified CF was significantly improved by the SEM experiment. The effectiveness of grafting was verified by FTIR and XPS, and the chemical functional groups on the surface of modified CF were increased. The microstructure of the failure interface of the composites was observed, the modification did not reduce the tensile strength of CF, and the interlaminar shear strength (ILSS) of modified CF/ epoxy resin composite was increased by 39.91%. It was found that the CF modified by FGO was beneficial to the improvement of the interface properties of CF/epoxy resin composite. This has positive academic significance for improving the interfacial and mechanical properties of CF composites.

Keywords

Carbon fibre graphene oxide interlaminar shear strength carbon fibre composites

Introduction

With the progress of science and technology and the rapid development of aviation, high-speed rail and other fields, there is an increasing demand for high-performance materials. While pursuing the basic properties such as material strength and stiffness, reducing quality and multifunction have become a new development direction. As ideal structural materials, CF composites have been widely used in national defence and military industry, aerospace, rail transit, automobile industry and other fields because of their high specific strength, high specific modulus, design flexibility, low density, high-temperature resistance and other performance characteristics [1-5]. In composites, CF as reinforcement is bonded with resin matrix through the interface layer. When the composite is loading, the stress is transmitted through the interface layer between the two-phase materials, so the interface performance will directly affect the stress transfer capability. At the same time, the existence of the interface layer can effectively inhibit the generation and propagation of damage at the micro-level in the composite, and then affect the mechanical properties of the composite [6]. As a common high-performance fibre material, CF has low surface energy, smooth surface and lack of active groups [7]. In order to utilise the excellent properties of CF in composites, it is necessary to improve the wettability and adhesion between fibre and resin as the reinforcing phase of composites. Interfacial modification has always been one of the hotspots in the research of CF composites. The common surface modification methods mainly include coating method [8-10], nano-particle modification [11-13], plasma treatment [14], chemical oxidation [15], electrochemical oxidation [16-18], etc. In the coating method and nano-particle deposition modification method, to protect the fibre a transition layer between the fibre and matrix is formed through physical or chemical action. The treatment with resin sizing agent is the most commonly used method in industrial production, but the improvement of most interface strength is not obvious [19]. The CF surface treatment method with plasma, chemical oxidation and electrochemical oxidation can significantly enhance the roughness, but it is easy to cause the surface damage to fibre and reduce the tensile strength of CF [20]. As a common chemical modifier, 3-aminopropyltriethoxysilane (APTES) has been used in glass fibre modification [21]. The special molecular structure of the APTES makes it possible to combine one end with the fibre molecular and the other end with the matrix molecular to improve the interfacial properties. Graphene oxide (GO) is a derivative material of graphene. It not only has a two-dimensional sheet structure and large surface area like the graphene but also contains a large number of oxygen-containing groups such as hydroxyl, carboxyl and epoxy [22], which can be effectively combine with matrix materials to improve the interface properties of composites. It is found that the functionalisation of GO surface can be realised by chemical reaction and intermolecular interaction between the oxygen-containing group and APTES [23, 24]. It is understood that although there are many studies on the surface modification of CF, there are few reports of studies on GO graft modified CF after functionalised treatment.

As mentioned above, the surface of CF was modified by functionalised graphene oxide (FGO) and the interfacial properties of composites after modification were studied in this paper, and the surface morphology between CFs before and after modification was compared by SEM. The surface chemical structures of CF before and after modification were analysed by FTIR and XPS. At the same time, the failure mechanism of the composite was discovered by SEM. Finally, the effect of FGO on the interfacial strength of CF is comprehensively evaluated. It is proven that the modified CF composites have excellent interfacial properties.

Experiment

Materials

Commercial polyacrylonitrile-based carbon fibre (T700SC-12 K) was supplied by Toray Industries, Inc (Japan). The epoxy resin (E-51) was purchased from Nantong Xingchen synthetic materials Co., Ltd. Epoxy resin curing agent (T-31) was purchased from Tianjin Jinning Sanhe Chemical Co., Ltd. Graphene oxide (GO) was purchased from Shanghai Yuanye Biotechnology Co., Ltd. Potassium permanganate, 3-aminopropyltriethoxysilane (APTES) and acetone are provided by Sinopharm Chemical Reagent Co., Ltd.

The preparation of FGO

The complete hydrolysis time of APTES in an aqueous solution is extremely short. Alcohols were produced during hydrolysis. Hydrolysis equilibrium is a chemical equilibrium system in which the increase of the product slows down the intensity of the reaction. So adding alcohol suppresses the hydrolysis rate [25]. To prevent the failure of solid siloxane formed by polymerisation owing to excessive hydrolysis of APTES. Based on the principle of hydrolysis equilibrium, a solution mixed APTES with absolute ethanol was prepared according to the ratio of 5:18. The solution was stirred evenly, 4 ml of deionised water was dropped into the solution and then stirred again with ultrasonic vibration for 5 min to make it uniform. An Ultrasonic cleaning machine with 40 KHz vibration (Shengsong, SCQ-1020b, China) is adopted. 200 mg GO was slowly put into the mixed solution abovementioned, fully stirred, heated in a 60°C water bath, and stirred the solution again with ultrasonic vibration for 30 min to obtain an FGO solution.

CF modification process

Before modification, the purchased CF has desized shall be treated according to the modification process shown in Figure 1. First, the CF was oxidised with 5% potassium permanganate solution as the oxidant for 2 h. The CF was repeatedly cleaned with deionised water and absolute ethanol and dried at 80°C. Then, the dried CF was immersed in the previously obtained FGO solution and stirred the solution again with ultrasonic vibration for 6 h to make it fully grafted, cleaned and dried.

The preparation of composites

The composite specimens were prepared by vacuum-impregnation process. Cut the modified or unmodified CF woven cloth into the appropriate size, four layers of CF plain-woven cloth are manufactured into a testpiece. Seal the testpiece with a vacuum bag, and suck out the air in the vacuum bag. Prepare the resin according to the ratio of 100:23 of epoxy resin (E-51) and curing agent (T-31). Introduce the prepared resin into the vacuum bag, let it stand at room temperature for 24 h to cure the resin, and then heat it at 60°C for 6 h to cure it more fully. After demolding, trim the edges and corners and cut them into corresponding sizes according to the characterisation experimental standards.

Characterisation

The interfacial bonding properties between adjacent layers were characterised by the interlaminar tensile shear test, and the effect of CF modification on interlaminar shear strength (ILSS) of CF composites was obtained. Test according to GB/T 33334-2016. Prepare composite testpieces with a size of 150 mm × 25 mm. The testpieces are divided into two groups: CF and FGO-KMnO₄-CF. At least 10 samples are tested in each group. A universal material testing machine (GOTECH, TCS-2000, China) is used for testing, and the test speed is set to 3 mm/min.

The surface morphology and fracture morphology of the composites at each stage of CF modification was observed by SEM (ZEISS, ULTRA-55, Germany), and the microstructure changes of the composites were analysed. Before the test, the non-conductive composite sample is sprayed with a conductive coating. The changes of CF surface chemical functional groups before and after modification were analysed by FTIR (Bruker, INVENIO-R, Germany). The scanning range was 400–4000 cm⁻¹ and the spectral resolution was 4 cm⁻¹. The chemical composition of the CF surface and the composite interface was characterised by XPS (Thermo Scientific K-Alpha, America), with a monochromatic Al Kα X-ray source and 400 μm spot size. The energy of 150 and 50 eV is used for full-spectrum scanning and narrow-spectrum scanning. The narrow spectrum C1s of each element take 284.8 eV as the reference peak.

Results and discussion

Functionalisation of GO

As shown in Figure 2, the solution of APTES is alkaline because of the presence of amino groups on APTES [26]. The –OH on the silanol reacts with the –COOH and other active groups on the GO surface and is grafted on the GO surface by generating a new chemical bond. At the same time, this reaction introduces a new chemical group –NH₂ to the GO surface [27], which was also confirmed by FTIR of GO before and after functionalisation. According to the analysis of the spectral line in Figure 3, when the wavenumber is about 3400cm⁻¹, the absorption peak corresponds to the stretching vibration of O–H. The 2975 cm⁻¹ absorption peak corresponding to –CH₂–. After functionalisation, the characteristic peak becomes wider and the intensity becomes higher because the N–H stretching vibration peak is superimposed with the O–H stretching vibration peak. Due to the stretching vibration of the C–N bond in aromatic amine, a new characteristic peak appeared at 1320 cm⁻¹, which indicates the existence of the –NH₂ group grafted on the GO surface. The characteristic peak with wavenumber of 1100 cm⁻¹ corresponds to the stretching vibration of Si–OH. The new characteristic peak at about 850 cm⁻¹ comes from the stretching vibration of Si–OOC. A wide characteristic peak appears at the wavenumber of 1645 cm−¹, which is corresponding to the bending vibration of N–H. Summarising the above analysis, it can be concluded that APTES was successfully grafted on the GO surface.

The surface morphology of GO particles was characterised by SEM, as shown in Figure 4. Figure 4(a) shows the surface morphology of the original GO, it can be seen that GO has excellent dispersion and no agglomeration. After APTES grafted treatment, the surface morphology of GO changed significantly (Figure 4(b)). The roughness of the GO flake structure increased significantly, and granular bulges were formed on the surface, which provided anchor points for grafting reaction and was more conducive to improving interface interaction in the modification process. The bonding force between GO sheet structures is enhanced so that a three-dimensional structure with better bonding performance is formed on the fibre surface.

CF surface modification

Surface morphology and properties

According to Figure 1, the modification process adopts the form of interlayer transition, and the modification process is divided into two steps: potassium permanganate pretreatment and graft. Through the tensile strength test of monofilament fibre (GB/T 31290-2014), it can be seen that the advantages of this modification are very obvious. According to the test results in Figure 5, before and after modification, the tensile strength of monofilament fibre is not decreased but is slightly enhanced. Compared to the method used in the literature [20], the system caused no damage to the fibre surface.

As shown in Figure 6(a–d), significant differences in surface morphology of CF before and after treatment can be observed through SEM images. It can be seen that in Figure 6(a), the surface of CF is relatively smooth and tidy before treatment. After KMnO₄ oxidation, sporadic etching marks appear on the surface of CF, as shown in Figure 6(b), which indicates that the skin-core structure on the surface of the oxidised fibre is slightly damaged. Figure 6(c) shows the surface morphology of CF modified by FGO, and the roughness of fibre surface is significantly enhanced. This phenomenon can be more clearly observed from the high magnification image (Figure 6(d)). The obvious increase in roughness is mainly owing to the flocculent or granular deposition layer formed by GO on the fibre surface under the bridge of APTES. From the high-power Figure 6(d), it can be observed that the fibre surface is covered with many flake particles of about 100 nm, and flocculent aggregates are formed on the fibre surface. This flocculent aggregate does not damage the dense graphite structure on the surface of CF, has a certain degree of repair effect on defects such as grooves on the surface of CF, and is effective in enhancing the tensile strength and interface strength of CF.

Surface element and chemical structure analysis

The chemical structure of the CF surface layer can be obtained by FTIR. As shown in Figure 7, the FTIR spectrum of CF, CF oxidised by potassium permanganate and FGO grafted CF was given. In the spectrum of untreated CF (de-sized via acetone), there are only a few insignificant absorption peaks around the wavenumbers of 800 and 2200 cm⁻¹. The peaks come from the stretching vibration of C=C and the out-of-plane bending vibration of C–H. This also shows that the surface of the original CF lacks the chemically active groups, which is consistent with the existing research results [28]. After being treated with potassium permanganate solution, a new absorption peak appears at 1012 cm⁻¹, which is speculated to be owing to the stretching vibration of C–O. It shows that part of the stable structure on the surface of CF is destroyed after oxidation, and potassium permanganate is effective for the pretreatment of CF. The preliminary pretreatment provides a good attachment anchor for FGO grafting. In Figure 7, the new strong and wide absorption peak at wavenumber 3360 cm⁻¹ is attributed to the stretching vibration of –NH, the absorption peak at wavenumber 1625 cm⁻¹ is –NH bending vibration. In addition, the characteristic peak at the wavenumber of 1100 cm⁻¹ changes significantly compared with not modification CF, which may be caused by the superposition of the stretching vibration peak of Si–O–Si and the stretching vibration peak of C–O. This result is consistent with FGO in Figure 2, which shows that the FGO can be grafted onto the CF surface to form a stable structure.

The surface elements of CF and FGO were studied by XPS (Figure 8). It can be seen that from the spectrum, the CF surface mainly includes C and O, while the modified CF surface adds N and Si elements, which indicates that new functional groups are introduced into the modified fibre surface. Figure 9(a–d) shows the narrow spectrum scanning curve of corresponding elements. To accurately analyse the ratio of each functional group, deconvolutions of narrow-spectrum curve by Gaussian–Lorentzian method [29]. The results of elemental analysis and the content of functional groups are shown in Table 1. The analysis shows that the content of O on the CF surface is increased from 58.6% to 59.86%, while the content of N is increased from 0.92% to 3.59%. At the same time, an Si element with a content of 4.92% is added to the modified CF surface. Through the chemical structure formula, it can be inferred that N and Si come from grafted FGO. This judgment also proves the correctness of FTIR. By comparing the C1s high-resolution spectra of CF, it can be obtained that there are two new peaks in modified CF at 285.6 and 287.7 eV, which is corresponding to C–N and N–C = O, respectively. This proves that APTES is grafted on the CF surface by chemical bonding. The C–O/C–OH is at 286.44 eV and yields a reduction from 12.78% to 2.44%. The C=O is at 287.65 eV and increases from 0.56% to 2.08%. The O–C=O is at 289.14 eV and decreases from 1.04% to 0.76%. The reason why the relative content of C=O increases significantly is that the grafted GO surface contains a large number of oxygen-containing functional groups including C=O [30]. In the N1s fitting curve of the modified CF (Figure 9(c)), the two sub-peaks at 399.81 and 402.02 eV are attributed to –NH– and –NH₂ on the APTES, respectively [31]. The introduction of –NH₂ and other groups increase the reaction opportunity between CF and epoxy resin. Figure 9(d) shows the Si2p fitting curve of modified CF. According to the data in Table 1, the relative contents of Si–C and Si–O–C are 4.48% and 0.44%, respectively. This shows that the Si–OH after APTES hydrolysis breaks and forms a new chemical bond with GO and CF, respectively. FGO deposited on CF surface can obtain better mechanical properties and chemical activity.

Table 1

Elemental analysis results and corresponding content of functional groups.

Sample	Eb%	C						O	N	Si
C–C	C–N	C–O/C–OH	O–C=O	C=O	N–C=O			Si–C	Si–O–C
CF	Eb	284.80	–	286.44	289.14	287.65	–	533.31	401.17	–	–
%	26.10	–	12.78	1.04	0.56	–	58.6	0.92	–	–
Modified CF	Eb	284.80	285.68	286.03	288.45	287.02	287.77	532.16	400.81	102.88	101.78
%	18.70	7.25	2.44	0.76	2.08	0.39	59.86	3.59	4.48	0.44

Interlaminar properties of modified CF composites

In order to characterise the effect of fibre surface modification on composite ILSS, it can be seen from the ILSS test results (Figure 10) that the ILSS of the modified CF composite is increasing by 39.91%. The ILSS of untreated CF/epoxy resin composites is 46.1 Mpa, and the ILSS of modified CF/epoxy resin composites is increased to 64.5 Mpa. By observing the SEM image of the failure interface after the interlaminar shear test (Figure 11(a–d)), the interface fracture of the untreated CF is relatively neat, and the separation between the fibre and the resin matrix is obvious, which indicates that the wettability of the matrix material to the CF is insufficient (Figure 11(a,b)). It can be seen from the high-resolution image that after stripping the resin, the fibre surface is smooth, there are shallow gullies on the surface, and there are no attachments. This shows that the interfacial adhesion between resin matrix and CF is too weak to provide high adhesion. By observing the failure interface of the modified CF composite (Figure 11(c,d)), it can be seen that there are a large number of serrated residual matrices on the fracture surface. The fracture mostly occurs in the resin matrix. After the failure of the specimen, more matrix materials are still attached to the fibre surface, and the embedding of CF is relatively complete. This shows that the interface between the fibre and the matrix is closely bonded and can withstand a higher load [32]. The surface roughness of the modified CF increases and provides more bonding anchors. At the same time, the improvement of interfacial properties makes the shear stress better transmitted from the matrix to the CF, which is conducive to the CF playing an important part in bearing mechanical load.

Analysis of interface modification mechanism

The main form of failure of fibre-reinforced composites is the separation of matrix material from the fibre surface [33]. It can be seen from the micromorphology of the failure interface in Figure 11 that the addition of FGO on the surface of CF forms a mechanical interlock between the two-phase materials, and the mechanical properties of the composite are improved. The grafting of FGO forms a transition layer on the surface of CF, and the existence of a polar chemical bond enhances the interface properties of the composites from multi-scale. When the composite material is damaged by force, small cracks first appear in the matrix material. With the increase of force, the destructive cracks will be transferred from the matrix to the fibre surface. Due to the great difference in mechanical properties between fibre and matrix, stress concentration will occur on the surface of micron fibre [34], which will lead to the separation of the matrix from fibre, and the transfer of cracks between adjacent fibres will lead to material failure. The introduction of FGO on the fibre surface can effectively hinder crack diffusion and improve the fracture toughness of the fibre surface. Its three-dimensional structure can be fully embedded in the matrix material and dissipate more energy during fracture. Compared with the literature [19], interfaces are only combined by physical contacts, and there is no strong chemical bond between interfaces, the process has obvious advantages. The existence of a transition layer can better realise the stress transfer between fibre and matrix, reduce the stress concentration at the weak interface on the fibre surface, and finally improve the mechanical properties of composites.

Conclusion

The surface modification of CF with GO treated by APTES not only improves the interfacial strength between the epoxy resin and CF but also the FTIR and XPS results show that many functional groups are introduced into the CF surface, improving the chemical activity of the CF surface and forms a chemical bond connection with epoxy resin. The special lamellar structure of GO improves the surface roughness of CF and forms many micromechanical connection anchors. By testing the mechanical properties of CF before and after modification, it is found that the modification has no great effect on the tensile strength of CF. The ILSS of modified CF/epoxy resin composites increased by 39.91%. The results show that the treatment of APTES and GO can significantly improve the interfacial properties of CF and epoxy resin, and this modification method has the advantage of environmental friendliness, which provides a new idea for the study of mechanical properties of CF/epoxy resin composites.

Footnotes

Disclosure statement

No potential conflict of interest was reported by the author(s).

References

Hung

, Lau

, Fox

, Surface modification of carbon fibre using graphene–related materials for multifunctional composites. Compos B-Eng. 2018; 133: 240–257.

Karger-Kocsis

, Mahmood

, Pegoretti

All-carbon multi-scale and hierarchical fibers and related structural composites: A review. Compos Sci Technol. 2019; 186: 107932.

, He

, Wang

, Constructing a simple anti-sandwich structure on carbon fiber surface for simultaneously strengthening and toughening the interphase of epoxy composites. Compos Struct. 2020; 240: 112075.

Chen

, Peng

, Zhao

, Grafting carbon nanotubes densely on carbon fibers by poly (propylene imine) for interfacial enhancement of carbon fiber composites. Carbon N Y. 2020; 158: 704–107710.

Zhou

, Zhong

, Zhao

, On the role of carbon nanotubes addition in carbon fiber-reinforced magnesium matrix composites. J Mater Sci. 2020; 55: 1–23.

Huang

, Liu

, Qiu

, Influence of ultrasonic treatment on the characteristics of epoxy resin and the interfacial property of its carbon fiber composites. Compos Sci Technol. 2002; 62: 2153–2159.

Sun

, Memon

, Gu

, Degradation of carbon fiber reinforced polymer from cathodic protection process on exposure to NaOH and simulated pore water solutions. Mater Struct. 2016; 49: 5273–5283.

Liu

, Zhang

, Song

, An effective surface modification of carbon fiber for improving the interfacial adhesion of polypropylene composites. Mater Des. 2015; 88: 810–819.

Zhang

, Cheng

, Guo

, Jin

, Liu

, Li

, Co-depositing bio-inspired tannic acid-aminopropyltriethoxysilane coating onto carbon fiber for excellent interfacial adhesion of epoxy composites. Compos Sci Technol 2020; 204: 108639.

10.

Yuan

, Jiang

, Wei

, PAI/MXene sizing-based dual functional coating for carbon fiber/PEEK composite. Compos Sci Technol. 2020; 201: 108496.

11.

Zhu

, Ruan

, Bao

LM.

Preparation of polyetherimide nanoparticles on carbon fiber surface via evaporation induced surface modification method and its effect on tensile strength and interfacial shear strength. Appl Surf Sci. 2018; 454: 54–60.

12.

Park

, Park

, Yang

, Enhanced interfacial, electrical, and flexural properties of polyphenylene sulfide composites filled with carbon fibers modified by electrophoretic surface deposition of multi-walled carbon nanotubes. Composites Part A. 2018; 109: 124–130.

13.

Zabihi

, Ahmadi

, Li

, Carbon fibre surface modification using functionalized nanoclay: a hierarchical interphase for fibre-reinforced polymer composites. Compos Sci Technol. 2017; 148: 49–58.

14.

Gravis

, Moisan

, Poncin-Epaillard

Surface character of plasma-modified carbon fiber: Correlation between surface chemistry and morphology of the single strand. Surf Interfaces. 2020; 21: 100731.

15.

Cheng

, Liu

, Xiao

, Effect of surface chemical modifications on the bioactivity of carbon fibers reinforced epoxy composites. Surf Coat Technol. 2019; 377: 124889–124889.

16.

Zhang

, Zhang

, Liu

, A novel surface modification of carbon fiber for high-performance thermoplastic polyurethane composites. Appl Surf Sci. 2016; 382: 144–154.

17.

Andideh

, Esfandeh

Effect of surface modification of electrochemically oxidized carbon fibers by grafting hydroxyl and amine functionalized hyperbranched polyurethanes on interlaminar shear strength of epoxy composites. Carbon. 2017; 123: 233–242.

18.

Wang

, Yang

, Mu

, Synergy of electrochemical grafting and crosslinkable crystalline sizing agent to enhance the interfacial strength of carbon fiber/PEEK composites. Compos Sci Technol. 2020; 203: 108562.

19.

Paipetis

, Galiotis

Effect of fibre sizing on the stress transfer efficiency in carbon/epoxy model composites. Composites Part A. 1996; 27: 755–767.

20.

Raphael

, Namratha

, Chandrashekar

, Surface modification and grafting of carbon fibers: a route to better interface. Prog Cryst Growth Charact Mater. 2018; 64: 75–101.

21.

Sorokin

, Petrova

GN.

Lubricants and coupling agents in the processes of the liquid-phase modification of the surface of carbon and glass fiber fillers in the production of structural materials: a review. Theor Found Chem Eng. 2020; 54: 737–744.

22.

, Zhou

, Lin

XD.

Preparation and characterization of functionalized graphene with ethanolamine. Acta Chim Sinica. 2011; 69: 1463–1468.

23.

Wan

, Tang

, Gong

, Grafting of epoxy chains onto graphene oxide for epoxy composites with improved mechanical and thermal properties. Carbon N Y. 2014; 69: 467–480.

24.

Bao

, Guo

, Song

In situ preparation of functionalized graphene oxide/epoxy nanocomposites with effective reinforcements. J Mater Chem. 2011; 24: 13290–13298.

25.

Subramanian

, Van Ooij

WJ.

Effect of the amine functional group on corrosion rate of iron coated with films of organofunctional silanes. Corrosion. 1998; 54: 204–215.

26.

Gao

, Jiang

, Guo

Study of the hydrolysis of 3-aminopropyltriethoxysilane (KH550) and the surface modification of silica. J B Univ Chem Technol (Nat. Sci. Ed.). 2012; 39: 7–12.

27.

Yan

, Liu

, Li

, A novel π bridging method to graft graphene oxide onto carbon fiber for interfacial enhancement of epoxy composites. Compos Sci Technol. 2021; 201: 108489.

28.

Zheng

, Fei

, Gu

, Constructing interfacial path for enhancing mechanical and thermal performances of carbon fiber/cyanate ester resin composite. Colloids Surf A. 2021; 617: 126311.

29.

Mahapatra

, Ramasamy

, Yoo

, A reactive graphene sheet in situ functionalized hyperbranched polyurethane for high performance shape memory material. RSC Adv. 2014; 4: 15146–15153.

30.

Bouazizi

, Vieillard

, Bargougui

, Entrapment and stabilization of iron nanoparticles within APTES modified graphene oxide sheets for catalytic activity improvement. J Alloys Compd. 2019; 771: 1090–1102.

31.

Lee

, Lee

, Byun

JH.

Catecholamine polymers as surface modifiers for enhancing interfacial strength of fiber-reinforced composites. Compos Sci Technol. 2015; 110: 53–61.

32.

LB.

Synergistic effects of interface slip and fiber fracture on stress-dependent mechanical hysteresis of SiC/SiC minicomposites. Compos Interfaces. 2020; 27: 1–72.

33.

Qin

, Wang

, Lu

, Uniform growth of carbon nanotubes on carbon fiber cloth after surface oxidation treatment to enhance interfacial strength of composites. Compos Sci Technol. 2020; 195: 108198.

34.

Bian

, Hui

, Meng

Thermal residual stress and interface binding effects on fiber reinforced composites. Arch Appl Mech. 2021; 91: 3315–103326.