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Fabrication of bacterial cellulose/polyaniline nanocomposite paper with excellent conductivity, strength and flexibility Guiqiang Fei, Yu Wang, Haihua Wang, Yongning Ma, Qian Guo, Wenhuan Huang, Dong Yang, Yanming Shao, and Yonghao Ni ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/ acssuschemeng.8b06306 • Publication Date (Web): 09 Apr 2019 Downloaded from http://pubs.acs.org on April 10, 2019

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ACS Sustainable Chemistry & Engineering

Fabrication of bacterial cellulose/polyaniline nanocomposite paper with excellent conductivity, strength and flexibility Guiqiang Fei†, Yu Wang†, Haihua Wang†*, Yongning Ma†, Qian Guo†, Wenhuan Huang†, Dong Yang†, Yanming Shao†, Yonghao Ni‡

† Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, 7# Xuefu Road , Weiyang district, Xi’an 710021, Shaanxi province, China

‡ Limerick Pulp and Paper Center, University of New Brunswick, 3 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada *Corresponding author: Tel: +86-18681808820. E-mail address: [email protected]

ABSTRACT: Bacterial cellulose/polyaniline (BC/PANI) nanocomposites display many potential applications in various fields. However, the conductivity and mechanical properties remain a challenge. Here, we developed a novel method to prepare BC/PANI nanocomposites via the chemical grafting of PANI onto epoxy modified BC (EBC), followed by the grafting of polyacrylamide (PAM). For comparison, an in-situ BC/PANI sample was also prepared. The grafting reaction between PANI and EBC and the retention of PANI on EBC were confirmed by FTIR, X-ray photoelectron spectroscopy and elemental analysis. The cross-section morphology of BC transformed into a three dimensional and continuous network structure with the incorporation of PANI. The effects of epoxy and PAM contents on the morphology, conductivity and mechanical properties of PANI-g-EBC and PANI-g-EBC3/PAM nanocomposites were investigated. Compared with those of the in-situ BC/PANI sample, the conductivity of PANI-g-EBC increased from 0.12 to 1.08 S/cm, while the stress increased from 8.18 to 18.47 MPa. With the addition of PAM, the conductivity of PANI-g-EBC/PAM nanocomposite paper further increased to 1.43 S/cm and the stress increased to 47.94 MPa. The conductivity of PANI-g-EBC3/PAM nanocomposites only decreased from 1.43 to 1.36 S/cm after refolding 160 times. PANI-g-EBC and PANI-g-EBC3/PAM nanofibers could be

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blended with conventional plant cellulose fiber to prepare flexible and high strength conductive composite paper. KEYWORDS: Conductive nanocomposites; epoxy chloropropane; modified BC; polyaniline; polyacrylamide.

Introduction High-strength, flexible and conductive cellulose nanocomposites have received growing interest.[1,2] As an important potential application in flexible electronic devices,[3,4,5] the development of conductive paper has become an active research field. Polyaniline (PANI) is considered as one of the most promising conducting polymer materials due to its facile synthesis, good environmental stability and controllable electrical conductivity via simple doping/dedoping chemistry.[6,7] PANI has also been used as a conductive polymer to improve the performance of flexible electronic devices.[8,9] However, its conjugated structure imparts PANI with poor processability. Therefore fabricating PANI composites becomes a continuing trend to extend the PANI application.[10] Cellulose is a considerably attractive material due to its abundance in nature, renewability, biodegradability, biocompatibility and good mechanical properties.[11,12] Among them, bacterial cellulose (BC) has received more and more attention since BC is pure and doesn’t contain hemicelluloses, lignin, pectin, or wax.[13] BC is produced from bacteria cultivations via biosynthesis, bacteria may include gluoconacetobacter xyliums and acetobacter xylinus.[14,15] BC possesses unique characteristics including high crystallinity, specific surface area, low thermal expansion, three-dimensional porous structure, anisotropic thermal conductivity in addition to good mechanical properties and biocompatibility.[13,16] Therefore, combining BC and PANI to make flexible and conductive BC/PANI nanocomposite membranes is an interesting concept. The in-situ polymerization of aniline onto a BC membrane leads to the formation of BC/PANI nanocomposites.[17,18,19] Hu et al. synthesized BC/PANI nanocomposites via in situ oxidative polymerization of aniline in the presence of BC membranes.[19] The highest conductivity was 0.05 S/cm, and its stress decreased by almost 4 times as a result of the PANI incorporation


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into BC membranes. Lin et al. developed a new route of limited interfacial polymerization by which aniline monomer was polymerized on the surface of BC membranes.[20] The surface resistivity decreased to 40.1 Ω.cm and the stress decreased by three times with the incorporation of PANI. The conductivity of BC/PANI nanocomposites made by this approach was very low. Recently some methods were put forward to improve the conductivity. For instance, protic ionic liquid based on N-butylguanidinium tetrafluoroborate (BG-BF4) was introduced to BC/PANI nanocomposites. The conductivity increased from 10-4 to 10-2 S/cm, however, significant decrease of the stress of such membranes to 5-6 MPa was observed.[21] Wan et al. increased the conductivity of BC/PANI from 0.82 to 1.7 S/cm with the addition of graphene.[22] In situ polymerization of aniline onto BC nanofibers is another approach to synthesize BC/PANI nanocomposites and subsequently flexible composite paper is obtained using the vacuum filtration technique.[11,12] Wang et al. obtained BC/PANI nanocomposites by in situ polymerization of aniline on wet BC nanofibers in DMF/H2O medium, the conductivity reached 5.1 S/cm when the aniline content was 200% based on the weight of BC nanofibers.[11] The crystalline structure of BC was fully hindered by amorphous PANI coating, which may affect the mechanical properties of BC/PANI nanocomposites. Gopakumar et al also obtained nanocomposites for sustainable microwave absorbers through the in situ polymerization of aniline on cellulose nanofibers, the conductivity is 0.314 S/cm.[12] Relative high mechanical properties can be achieved for the BC/PANI nanocomposites prepared using the first approach, since BC membranes of high modulus and stress were used as raw material. But the conductivity was very low and stress also decreased significantly with the incorporation of PANI. Additionally, this approach is difficult to scale since the product yield is limited. The second approach is able to produce a large amount of BC/PANI nanocomposites, but the conductivity improves by compromising the mechanical properties. How to have satisfactory results between conductivity and mechanical properties for BC/PANI nanocomposites remains a big challenge. Herein, a novel approach was proposed to prepare BC/PANI nanocomposites with high conductivity and mechanical properties. First, epoxy groups were incorporated into BC structure by chemical grafting of epoxy chloropropane (ECP) onto BC. Then PANI was chemically grafted onto epoxy modified BC (PANI-g-EBC) to improve the interaction and compatibility between PANI and BC, as well as to promote the formation of more uniform and continuous conductive



paths. Afterwards, a moderate amount of polyacrylamide (PAM) was introduced into PANI-g-EBC3 nanofibers to further improve the conductivity and mechanical properties via enhancing the interactions between fibers and PANI while maintaining the crystal characteristic of BC. The structure, morphology and properties of PANI-g-EBC and PANI-g-EBC3/PAM nanocomposites were systematically investigated. PANI-g-EBC and PANI-g-EBC3/PAM nanofibers can also be blended with plant cellulose fiber to make flexible and conductive paper, and the related properties were also studied.

Experimental Materials Aniline was supplied by Tianjin Chemical Reagent Factory and distilled under reduced pressure before utilization. Bacterial Cellulose (BC) was obtained from Guilin Qi Hong Technology Co., Ltd. Epoxy chloropropane (ECP) was supplied by Tianjin Tianli Chemical Reagent Co., Ltd. Hydrochloric acid (HCl) was provided by Tianjin Institute of Chemical Reagents. Ammonium persulfate (APS) was bought from Hedong District of Tianjin Hongyan reagent Factory. NaOH was obtained from Tianjin Tianli Chemical Reagent Co, Ltd. Polyacrylamide (PAM) was purchased from Tianjin Hongyan reagent Factory.

Preparation of epoxy modified BC (EBC) 0.2 wt% BC solution was prepared by diluting BC in distilled water under vigorous stirring for 20 min. The solution was heated up to 80°C, then ECP of different content was added. The pH value was adjusted to 11 with 1 mol/L NaOH. Epoxy modified BC (EBC) solution was thereby obtained after 5 h reaction. The as-prepared samples were named EBC1, EBC2, EBC3, EBC4 and EBC5, in which the 1-5 represents the mass fraction of ECP is 1.1 g/L, 2.2 g/L, 3.3 g/L, 4.4 g/L, 5.5 g/L, respectively.

Preparation of PANI-g-EBC, in situ BC/PANI and PANI-g-EBC3/PAM nanocomposite paper 98.05 μL aniline was added into the above EBC solution, and the reaction was kept at 80°C for 2 h. Then the reaction system was placed in an ice-water bath and the solution was cooled down to 5°C. Afterwards, 0.455 g ammonium persulfate (APS) was dropped into the reaction solution, after which 1


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mol/L HCl was utilized to adjust the pH value to 1-2. After 24 h, polyaniline grafted EBC (PANI-g-EBC) suspensions were obtained, and the samples were named as PANI-g-EBC1, PANI-g-EBC2, PANI-g-EBC3, PANI-g-EBC4 and PANI-g-EBC5 based on the ECP content. In situ BC/PANI was prepared according to the same procedure as abovementioned except that the EBC was replaced by BC. PAM of different concentrations was added into 100 g PANI-g-EBC3 suspensions, the temperature was heated up to 60°C and the reaction was kept for 2 h to prepare PANI-g-EBC3/PAM suspensions. The samples were designated as PANI-g-EBC3/PAM1, PANI-g-EBC3/PAM2, PANI-g-EBC3/PAM3, PANI-g-EBC3/PAM4 and PANI-g-EBC3/PAM5 when the PAM concentration was 0.4g/L, 0.6 g/L, 0.8 g/L, 1.0 g/L and 1.2 g/L, respectively. Vacuum filtration technique was adopted to fabricate nanocomposite paper. After filtration, the nanocomposite paper was washed several times with distilled water and freeze dried in a LGJ-12 freeze dryer for 24 h. The PANI-g-EBC, in situ BC/PANI and PANI-g-EBC3/PAM nanocomposite paper was obtained after being peeled off the filter paper.

Preparation of conventional plant cellulose fiber/nanofiber nanocomposite paper The PANI-g-EBC3 suspension or PANI-g-EBC3/PAM suspension was mixed with plant cellulose fiber at different ratios in a blender with a stirring speed of 3000 rpm. Then, the obtained suspension was formed into paper with a handsheet machine and the as-prepared paper was pressed and dried at 105°C (0.5 MPa) for 5min, followed by drying at room temperature for 12 h. As a result, the conductive nanocomposite papers were fabricated, in which the mass fraction of PANI-g-EBC3 and PANI-g-EBC3/PAM2 is 5%, 10%, 15%, 20%, 25%, 30%, respectively. 60 g/m2 nanocomposite paper sheets were prepared according to TAPPI methods (T205 SP-95).

Characterizations The structure of prepared nanocomposites was characterized by Fourier transformed infrared (FTIR, VECTOR-22, Germany) and X-ray photoelectron spectroscopy (XPS, AXIS SUPRA, UK). The surface and cross-section morphology were observed by scanning electron microscopy (SEM, S-4800, Hitachi, Japan) and transmission electron microscopy (TEM, S-570, US). The elemental composition was analyzed by organic elemental analysis (Vario EL III, Germany). The conductivity



was measured by four-point probe technique (BD-86A, China). The mechanical properties were measured using a universal testing machine (GT-U55, China). The thermal stability of samples was performed by thermogravimetric analyses (TGA, TGA Q500, US). The crystalline phases were characterized by X-ray diffraction instrument (XRD, R-600, Japan). The tearing index, folding endurance, tensile index test were measured according to paper bursting tester (DCP-MIT13, China), paper folding tester (DCP-MIT135A, China) and stress tester (062/969921, China)

Results and discussion Structure, morphology and conductivity analysis of EBC and PANI-g-EBC nanocomposite

Fig.1. Synthesis mechanism of EBC (A) and PANI-g-EBC nanocomposites (B); Schematic model of PANI-g-EBC nanocomposites (C); and TEM images of PANI, BC, EBC and PANI-g-EBC nanocomposites (D).

The synthesis mechanisms of EBC and PANI-g-EBC were exhibited in Fig.1A and 1B. ECP was incorporated into nanosized bacterial cellulose (BC) via the condensation reaction between epoxy groups in ECP and -OH groups in BC. PANI was subsequently chemically grafted into BC through the reaction between epoxy groups and amine groups, the schematic model is shown in Fig.1C. The corresponding TEM morphology is shown in Fig. 1D. Pure PANI displayed spherical morphology with particle sizes in the range of 20-90 nm, and BC presented 3D network fabric structure. The


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incorporation of ECP into BC did not significantly alter the network structure of BC. The PANI-g-EBC sample displayed a 3D network structure constituted by PANI modified BC nanofibers. Some spherical PANI particles were also evident in the TEM image of PANI-g-EBC nanocomposite. In our previous study, when conductive polymer/cellulose fibers were prepared through in situ oxidation polymerization, conductive polymers not only deposited on the fiber surface, but also distributed inside the cellulose fiber wall to form 3D conductive networks.[23] Correspondingly, PANI can also form 3D conductive networks on the surface and inside of the EBC nanofiber, the spherical particles only represent a fraction of PANI, and partial PANI form uniform and continuous conductive film. The SEM morphology of PANI-g-EBC nanocomposites formed with different reaction times was also provided, as shown in Fig.2. As the reaction proceeded, more and more PANI particles formed on the EBC nanofibers, favorably forming a continuous conductive network.

Fig.2. SEM images of PANI-g-EBC nanocomposites formed with the reaction time of 0 min, 20 min, 40 min, 3 h, 6 h, 10 h, 16 h and 24 h.

The XPS N1s spectra of aniline-g-EBC and PANI-g-EBC nanocomposites were shown in Fig.3A and 3B, respectively. Two distinct peaks corresponding to -NH2 and -NH species were found at 399.4 and 398.4 eV (Fig.3A), which can be ascribed to free aniline monomers and -NH groups formed by the reaction of amine groups in PANI with epoxy groups in EBC.[24, 25] It also indicates the presence of aniline in the reaction system as free monomers. Three peaks at 399.1 eV, 398.4 eV and 397.6 eV corresponding to positively charged nitrogen (-NH3+), benzenoid amine (-NH-) and quinoid amine (-N=), were identified for the PANI-g-EBC nanocomposite (Fig.3B), demonstrating the oxidation polymerization of aniline monomers with the addition of initiator APS.[25] The related peak area ratio



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was shown in Table 1, the presence of -NH3+ peak confirmed the doped PANI.

Fig.3. High resolution XPS N 1s spectra of aniline-g-EBC (A) and PANI-g-EBC nanocomposite (B); FTIR spectra of BC, EBC, PANI, PANI-g-EBC nanocomposites(C); SEM images of EBC (D); SEM surface (E) and cross-sectional (F) images of BC; SEM surface (G) and cross-sectional images (H) of PANI-g-EBC3 nanocomposites. Table 1. Peak ratio calculated based on XPS spectra Samples

Peak area ratio (%) +

-NH2 (399.4 eV)

-NH3 (399.1 eV)

-NH- (398.4 eV)

-N= (397.6 eV)

Aniline-g-EBC

21.49

-

78.51

-

PANI-g-EBC

-

12.22

39.69

48.09

FTIR spectra of BC and EBC were shown in Fig.3C. In the FTIR spectra of BC, those at 3340, 2800-3000, 1055 cm-1 were ascribed to the -OH, C-H stretching modes and absorption peaks of C-O-C, respectively.[20] The characteristic absorption peaks of BC were also observed in the FTIR spectra of EBC, indicative of the intact BC structure. However, a new peak at 910 cm-1 was detected in the FTIR spectra of EBC, which can be assigned to the epoxy group, demonstrating the successful incorporation of ECP into BC.[26] In Fig.3C, the characteristic peaks of PANI at 1467 and 1564 cm-1 were found in the spectra of PANI-g-EBC nanocomposites, and the characteristic absorption peak of epoxy group at 910 cm-1 disappeared, supporting the successful grafting of PANI into EBC.[27] SEM surface images of EBC, BC, PANI-g-EBC3 and cross-sectional images of BC and PANI-g-EBC3 nanocomposites were also shown in Fig.3D, Fig.3E, 3G, 3F and 3H, respectively. The surface morphology of BC, EBC and PANI-g-EBC3 nanocomposites displayed 3D network structures, furthermore, the 3D network structure of PANI-g-EBC3 became more compact compared with BC. Additionally, a layered structure was evident for the cross section of BC (Fig.3F), while dense 3D network structure was found for the PANI-g-EBC3 nanocomposites (Fig.3H).


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Effects of epoxy content on structure and properties of PANI-g-EBC. The epoxy content of PANI-g-EBC nanocomposites was determined through a hydrochloric acid-acetone method, as shown in the supporting information (Equation.S1),[28] and it increased from 0.026 to 0.151 mol/100g when the ECP concentration was increased from 1.1 to 3.3 g/L, and then increased to 0.168 mol/100g when the ECP concentration was further increased to 5.5 g/L (Table.S1). The retention of ECP on BC increased from 44.1% to 85.3% by increasing the ECP concentration from 1.1 to 3.3 g/L, then decreased to 56.9% by further increasing the ECP concentration to 5.5 g/L. The decrease of retention could be due to the self-polymerization of ECP at a higher ECP concentration, the self-polymerization mechanism of ECP is shown in Fig.S1.[29] As the epoxy content increased, the retention of PANI increased from 47.7% to 99.8% (Table.S2). It is also worthy to note that the PANI retention in BC/PANI was 41.1%, which is much lower than that of PANI-g-EBC. The results indicate that the incorporation of epoxy groups into BC is beneficial for the graft and retention of PANI on BC. The SEM and TEM morphology of PANI-g-EBC nanocomposites was shown in Fig.4. Significant PANI aggregation was observed for the PANI-g-EBC1 sample due to the limited amount of epoxy groups on BC, which was also supported by the TEM analysis. By increasing the ECP concentration, the large PANI aggregations disappeared, demonstrating the uniform distribution of PANI in BC. Partial PANI was also evident inside BC, indicating that aniline monomers penetrate into porous BC, leading to the oxidative polymerization inside BC, as demonstrated by TEM morphology. Our previous study showed that the oxidative polymerization did occur on the fiber surface and inside the porous fiber wall,[23] which is beneficial to increase the connected conductive paths, thereby increasing the conductivity. By further increasing the ECP concentration, fibers became aggregated, as a result of excessive interactions among fibers. The representative models for PANI-g-EBC1, PANI-g-EBC3 and PANI-g-EBC5 are also given in Fig.4C, which shows that the PANI-g-EBC samples form uniform and connected conductive paths.



Fig.4. SEM (A), TEM (B), the representative models (C) for PANI-g-EBC1, PANI-g-EBC3, PANI-g-EBC5 nanocomposites.

The conductivity reached the max of 1.08 S/cm for the PANI-g-EBC3 sample, which can be attributed to the formation of more uniform and conductive paths (Fig.5A). In contrast, the decreased conductivity for samples PANI-g-EBC4 and PANI-g-EBC5 can be ascribed to the inhomogeneous distribution of PANI in these samples. In addition, excessive aniline monomers react directly with epoxy groups, resulting in decreased conductivity. The stress of PANI-g-EBC nanocomposites is also investigated, as shown in Fig.5B. By increasing the ECP concentration from 1.1 to 3.3 g/L, the stress increased from 12.41 to 18.47 MPa, the elongation at break also increased from 2.49% to 3.46%. At a low ECP concentration, the formation of large PANI aggregations led to decreased interactions among fibers, thereby decreasing the mechanical properties. By increasing the ECP concentration, the stress increased due to the enhanced interactions among fibers. TGA and DTG curves of PANI-g-EBC nanocomposites were also


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provided (Fig.5C and 5D). The decomposition temperature at weight loss of 10% for PANI-g-EBC3 nanocomposites increased to 342°C, which was compared to that of PANI-g-EBC1 (297°C) and that of PANI-g-EBC5 nanocomposite (320°C). The DTG results also indicated that the temperature at the maximum decomposition rate increased from 274°C to 352°C for the PANI-g-EBC sample, which can also be attributed to the increased interactions.

Fig.5. Electrical conductivity of PANI-g-EBC1, PANI-g-EBC2, PANI-g-EBC3, PANI-g-EBC4, PANI-g-EBC5 composites (A); Stress-strain curves of PANI-g-EBC1, PANI-g-EBC2, PANI-g-EBC3, PANI-g-EBC4, PANI-g-EBC5 composites (B); TGA decomposition curves of PANI-g-EBC1, PANI-g-EBC3, PANI-g-EBC5 (C); DTG curves of PANI-g-EBC1, PANI-g-EBC3, PANI-g-EBC5 composites (D).

Comparison study between in situ BC/PANI and PANI-g-EBC nanocomposites. Fig. 6A shows XRD patterns of BC/PANI and PANI-g-EBC nanocomposites, those at 14.7°, 18.2°, and 22.7° were typical for BC.[18] The peak intensity increased for the PANI-g-EBC sample, indicative of increased crystallinity degrees. Compared with BC/PANI blend, the stress of



PANI-g-EBC also increased from 8.18 MPa to 18.47 MPa, and the elongation at break increased from 2.12% to 2.93% (Fig.6B). The improved mechanical properties can be ascribed to the increased 3D network structure and crystallinity, as discussed in the previous section. TGA results (Fig.6C) revealed that the decomposition temperature of PANI-g-EBC nanocomposites was enhanced to 342oC compared with BC/PANI nanocomposites (267°C) when the weight loss was 10%. DTG results also showed that the temperature at the maximum decomposition for PANI-g-EBC increased from 315°C to 352°C, indicative of the enhanced thermal stability (Fig.6D).

Fig.6. XRD pattern (A), Stress-strain curves (B), TGA decomposition curves (C) and DTG curves (D) of BC/PANI and PANI-g-EBC nanocomposites.

The TEM morphology of BC/PANI nanocomposites showed that BC/PANI nanocomposites were composed of free PANI particles and fiber networks with distinct PANI agglomerations on fibers (Fig.7A). SEM surface (Fig.7B), cross-sectional (Fig.7C) morphology and high magnification SEM images (Fig.7D) also indicated the presence of PANI aggregation on the fiber surface. In contrast, few free PANI particles appeared in the TEM morphology of PANI-g-EBC, only some PANI particles were evident on the fiber surface (Fig.7G). Compared with the cross-sectional morphology of BC/PANI, the PANI-g-EBC showed more compact structure, with finer fibrils (Fig.7I), which is responsible for the fact that the PANI-g-EBC sample exhibited higher conductivity and mechanical properties. The electrical conductivity of PANI-g-EBC3 was 1.08 S/cm, which was almost one order higher than that of BC/PANI blend, supporting the conclusion that the chemical graft method was much more efficient for improving the uniform distribution of PANI in nanocomposites, thereby improving conductive networks, thus the conductivity. EDS mapping images of N element on nanofibers show that N elements uniformly distribute on the surface of nanofibers, forming the interconnected conductive network (Fig.7E and 7K).


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Fig.7. TEM morphology (A, G), SEM surface morphology (B, H), SEM cross-section morphology (C, I), high magnification SEM images (D, J) and EDS mapping (E, K), schematic model (F, L) of BC/PANI nanocomposites and PANI-g-EBC nanocomposites.

Improvement of conductivity and mechanical property with PAM addition To further improve the conductivity and mechanical properties of composite paper, polyamide (PAM) was added to the PANI-g-EBC3 system. PAM is able to impart more hydrogen bonding between PANI and PANI-g-EBC3 fibers, thereby forming interpenetrating networks with PANI-g-EBC3 fiber and increasing the mechanical properties, the schematic reaction and model of PANI-g-EBC3/PAM, as shown in Fig.8.



Fig.8. Schematic reaction between PANI-g-EBC3 fiber and PAM and representative model of

PANI-g-EBC3/PAM nanocomposites FTIR spectra of PANI-g-EBC3/PAM nanocomposites were shown in Fig.9A. For the PANI-g-EBC3/PAM sample, the peak at 1668 cm-1 was ascribed to the C=O stretching modes, indicative of PAM.[30] The characteristic absorption peaks of PANI at 1480 and 1560 cm-1 also appeared in the FTIR spectra of PANI-g-EBC3/PAM.[27] Fig.9B showed XRD patterns of PAM, BC and PANI-g-EBC3/PAM nanocomposites. The XRD patterns BC showed typical peaks at 14.4o, 16.6o, 22.7o [18,31] all of which appeared in the PANI-g-EBC3/PAM sample, demonstrating that the crystalline structures of BC are intact in the presence of PAM. By increasing the PAM content, these peaks became weaker and weaker. The UV absorption spectrum of PANI-g-EBC3/PAM (Fig.9C) showed a shoulder-like absorption at 220~350 nm, corresponding to π-π* benzenoid rings and a strong absorption of polaron band at 740~800 nm.[32,33] Additionally, those at 220~350 nm of the PANI-g-EBC3/PAM2 nanocomposites red-shifted and became stronger compared to those of the PANI-g-EBC3/PAM5, indicative of conductive conjugated double bonds. As the PAM concentration increased from 0.0 to 0.6 g/L, the N content increased from 2.496% to 4.072%, and then decreased to 2.555% by increasing the PAM concentration further to 1.2 g/L (Table 2). By increasing the PAM concentration, more and more PAM was adsorbed on PANI-g-EBC3 nanofiber via hydrogen bonding. However, some PAM desorbed from nanofibers by further increasing the PAM concentration, which is responsible for the decreased N content (Table 2).


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Fig.9. FTIR spectra of PANI-g-EBC3/PAM nanocomposites with different PAM content (A); XRD patterns of PANI-g-EBC3/PAM nanocomposites (B); UV spectra of PANI-g-EBC3/PAM nanocomposites (C). Table 2. Elemental content of PANI-g-EBC3 and PANI-g-EBC3/PAM nanocomposites

Samples

N (%)

C (%)

O (%)

H (%)

PANI-g-EBC3

2.496

46.950

44.383

6.171

PANI-g-EBC3/PAM1

2.348

46.43

45.084

6.138

PANI-g-EBC3/PAM2

4.072

48.90

40.967

6.061

PANI-g-EBC3/PAM3

3.993

48.91

41.024

6.073

PANI-g-EBC3/PAM 4

3.736

48.73

41.460

6.074

PANI-g-EBC3/PAM 5

2.555

46.72

44.579

6.146

By increasing the PAM concentration from 0.4 to 1.2 g/L, the fiber network becomes denser and denser, and small spherical PANI particles are also formed on the surface of fibers (Fig.10A). At a high PAM concentration (e.g., 1.2 g/L), PAM might form polymer films on the fiber surface. In comparison with PANI-g-EBC3, the stress of PANI-g-EBC3/PAM increased from 18.97 to 47.94 MPa, the elongation at break increased from 2.93% to 4.58% (Fig.10B), which can be ascribed to the enhanced interaction between fibers as a result of PAM addition. Moreover, the decomposition

temperature

at

the

weight

loss

of

10%

for

PANI-g-EBC3/PAM1,

PANI-g-EBC3/PAM3 and PANI-g-EBC3/PAM5 is 207°C, 236°C, and 252°C, respectively, indicative of increased thermal stability due to the enhanced interactions (Fig.10C).



Fig.10. SEM surface morphology of PANI-g-EBC3/PAM1, PANI-g-EBC3/PAM3, PANI-g-EBC3/PAM5 nanocomposites (A); Mechanical property (B) and TG thermograms (C) of PANI-g-EBC3/PAM nanocomposites; Electrical conductivity of PANI-g-EBC3/PAM nanocomposites (D). Table 3. The Electrical conductivity of PANI-g-EBC3, PANI-g-EBC3/PAM and BC/PANI/PAM nanocomposites Samples

Electrical conductivity (S/cm)

PANI-g-EBC3

1.08

PANI-g-EBC3/PAM

1.43

BC/PANI/PAM

0.97

The conductivity of PANI-g-EBC3/PAM nanocomposites increased from 1.24 to 1.43 S/cm when the PAM concentration was increased from 0.4 to 0.6 g/L, and then decreased to 1.02 S/cm when the PAM concentration increased to 1.2 g/L (Fig.10D). The main reason for the decreased conductivity at a very high PAM concentration is that PAM is non-conductive, and excessive amounts on the fiber surface destroyed the conductive paths. The conductivity of PANI-g-EBC3/PAM (1.43 S/cm) was also higher than that of PANI-g-EBC3 (1.08 S/cm, Table 3). The conductivity of BC/PANI/PAM (0.97 S/cm, Table 3) was also higher than that of BC/PANI (0.12 S/cm). These results support the notion that moderate amounts of PAM can improve the nanocomposite conductivity via enhancing the interactions among fibers and PANI (Table 3). The conductivity of PANI-g-EBC and PANI-g-EBC3/PAM2 nanocomposites under different bending conditions was also measured (Fig.11). The conductivity of PANI-g-EBC3 nanocomposites was 10.18% lower after folding 50 times. In contrast, the conductivity of PANI-g-EBC3/PAM nanocomposite was only 4.89% lower after folding 160 times. The conductivity of PANI-g-EBC3/PAM under bending conditions improved with the PAM addition.


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Fig. 11. Electrical conductivity of PANI-g-EBC (A) and PANI-g-EBC3/PAM2 (B) nanocomposites under different bending conditions.

Preparation of flexible conductive nanocomposite paper PANI-g-EBC3 and PANI-g-EBC3/PAM2 conductive fibers were blended with original cellulose fibers to make flexible conductive nanocomposite paper, the resistivity, tearing index, folding endurance and tensile index of nanocomposite paper were shown in Fig.12. By increasing the PANI-g-EBC3 content from 5% to 30%, the resistivity decreased from 9.92 kΩ/cm to 3.21 kΩ/cm, the tearing index increased from 6.15 to 9.02 mN.m2/g, the folding endurance increased from 13 to 50 times, and the stress increased from 13 to 30.11 N.m/g, followed by a slight decrease when the PANI-g-EBC3 addition was higher than 20%. The tearing index, folding endurance and tensile index for original paper made of the original cellulose fibers were 5.49 mN.m2/g, 9 times and 8.89 N.m/g, respectively. The results suggest that the incorporation of nanosized PANI-g-EBC3 conductive fibers into conventional cellulose fibers can enhance the interactions among cellulose fibers, thereby significantly increasing the paper strength. Compared with PANI-g-EBC3/plant fiber nanocomposite paper, the resistivity of PANI-g-EBC3/PAM2/cellulose fiber nanocomposite paper, decreased from 3.13 to 1.56 KΩ/cm with the addition of only 10% PANI-g-EBC3/PAM2 nanofibers. The tearing index, folding endurance and tensile index reached 17.92 mN.m2/g, 171 times and 43.67 N.m/g when the PANI-g-EBC3/PAM2 content was 25%, which was much higher than those of the PANI-g-EBC3 nanocomposite paper (9.02 mN.m2/g, 50 times and 30.11 N.m/g). The as-prepared nanocomposite paper was foldable, rollable and bendable (Fig.12J). It can be concluded that the incorporation of PANI-g-EBC3/PAM2 nanofibers is able to generate strong conductive networks for cellulose fibers, leading to comprehensive improvement of conductivity and mechanical properties.



Fig. 12. The volume resistivity (A), the tear index(B), the folding endurance (C), the tensile index (D) of composite paper with different contents of PANI-g-EBC3 conductive fibers; Surface resistivity (E), tearing index (F), folding endurance (G), and tensile index (H) of conductive nanocomposite paper with different contents of PANI-g-EBC3/PAM conductive fibers; Strengthening mechanism of nanosized conductive fiber on composite paper (I); Bending, rolling and folding photograph of nanocomposite paper (J).

The strengthening mechanism of adding nanosized conductive fibers is summarized in Fig. 12I. Generally, paper strength depends mainly on the hydrogen bonds between fibers. The incorporation of nanofibers is able to increase the number of hydrogen bonds between fibers, and functions as “bridges” to connect the plant cellulose fibers; furthermore, the increased interactions between fibers also leads to denser and stronger 3D networks, as demonstrated by the SEM results (Fig.12I(b)). By increasing the amount of nanofibers, more and more nanofibers are inserted into cellulose fibers, there are more interactions between nanofibers and original fibers. Nanofibers simultaneously functionalize as nanofillers and bridges for original fibers, thereby improving the interaction between fibers to improve the mechanical properties of composite paper, the bridging-filling function mechanism is shown in Fig.12I(c). However, when the cellulose fibers are


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totally filled with PANI-g-EBC3 fibers, the original hydrogen bonds between fibers are almost totally destroyed and replaced by the interactions between conductive nanofibers. The interactions between conductive nanofibers are weakened since the surface of nanofibers was covered by conductive PANI, resulting in decreased mechanical properties (Fig.12I(d)).

Conclusion The conductivity and mechanical properties of bacterial cellulose/polyaniline (PANI) nanocomposites were significantly improved by chemical grafting of PANI onto epoxy modified BC (EBC), and a higher graft efficiency of PANI on EBC was achieved by increasing the epoxy content. PANI aggregations on fiber surfaces occurred at a low epoxy range, and fiber aggregation was observed at a high epoxy range. In contrast, more uniform and connected networks were formed when the epoxy content was 0.151 mol/100g, resulting in the improved conductivity and mechanical properties. PANI-g-EBC nanocomposite paper also displayed higher conductivity and mechanical properties than that of the in-situ BC/PANI sample. By adding moderate amounts of PAM into PANI-g-EBC, the conductivity and mechanical properties of PANI-g-EBC3/PAM nanocomposite paper were further improved, which is due to the enhanced interactions between fibers and the PAM-aided denser fiber networks. A slight decrease in the conductivity of PANI-g-EBC3/PAM nanocomposite was observed after 160 folds. Based on bridging-filling function mechanisms, the as-prepared PANI-g-EBC and PANI-g-EBC3/PAM nanofibers can also blend with conventional cellulose fibers to make flexible and conductive composite paper of high strength. These novel nanocomposites may have prosperous applications in various fields such as the flexible electronic devices, antistatic and electromagnetic materials. Supporting Information Data and discussion on the determination of epoxy value.

Acknowledgements The authors express sincere thanks to the Key Research and Development Program of Shaanxi Province--International Cooperation Project (No. 2018KW-007), Key Research and



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Development Program of Shaanxi Province (No. 2017GY154), Innovation Supporting Plan of Shaanxi Province-Innovation Research Team (No. 2018TD-015), National Natural Science Foundation of China (No. 21505089), Scientific Research Foundation (SRF) for Returned Overseas Chinese scholars (ROCS), State Education Ministry (SEM) (No. [2012]1707).

References 1. Ma, Y.; Xie, X.; Lv, R.; Na, B.; Ouyang, J. B.; Liu, H. Nanostructured Polyaniline-Cellulose Papers for Solid-State Flexible Aqueous Zn-Ion Battery. ACS Sustainable Chem. Eng. 2018, 6 (7), 8697-8703, DOI 10.1021/acssuschemeng.8b01014. 2. Wang, H.; Sun, L.; Fei, G.; Fan, J.; Shi, X. A Facile Approach to Fabricate Waterborne, Nanosized Polyaniline-Graft-(Sulfonated Polyurethane) as Environmental Antistatic Coating. J. Appl. Polym. Sci. 2017, 134 (41), 45412, DOI 10.1002/app.45412. 3. Veerubhotla, R.; Das D.; Pradhan, D. A Flexible and Disposable Battery Powered by Bacteria Using Eyeliner Coated Paper Electrodes. Biosens. Bioelectron. 2017, 94, 464-470, DOI 10.1016/j.bios.2017.03.020. 4. Sadak, O.; Sundramoorthy, A. K.; Gunasekaran, S. Facile and Green Synthesis of Highly Conductive Graphene Paper. Carbon. 2018, 138, 108-117, DOI 10.1016/j.carbon.2018.05.076. 5. Tang, Y.; Mosseler, J. A.; He, Z.; Ni, Y. Imparting Cellulosic Paper of High Conductivity by Surface Coating of Dispersed Graphite. Ind. Eng. Chem. Res. 2014, 53 (24), 10119-10124, DOI

10.1021/ie500558f. 6. Liu,

X.;

Wen,

N.;

Wang,

X.;

Zheng,

Y.

A

High-Performance

Hierarchical

Graphene@Polyaniline@Graphene Sandwich Containing Hollow Structures for Supercapacitor Electrodes. ACS Sustainable Chem. Eng. 2015, 3 (3), 475-482, DOI 10.1021/sc5006999. 7. Wang, H.; Wen, H.; Hu, B.; Fei, G.; Shen, Y.; Sun, L. Facile Approach to Fabricate Waterborne Polyaniline Nanocomposites with Environmental Benignity and High Physical Properties. Sci. Rep. 2017, 7, 43694, DOI 10.1038/srep43694. 8. Liu, Y.; Sun, B.; Li, J.; Cheng, D.; An, X.; Yang, B.; He, Z.; Lutes, R.; Khan, A.; Ni, Y. Aqueous Dispersion of Carbon Fibers and Expanded Graphite Stabilized from the Addition of Cellulose


Page 21 of 24 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Nanocrystals to Produce Highly Conductive Cellulose Composites, ACS Sustainable Chem. Eng. 2018, 6 (3), 3291-3298, DOI 10.1021/acssuschemeng.7b03456. 9. Shao, L.; Wang, Q.; Ma, Z.; Ji, Z.; Wang, X.; Song, D. A High-Capacitance Flexible Solid-State Supercapacitor Based on Polyaniline and Metal-Organic Framework (Uio-66) composites. J. Polym. Sci. 2018, 379, 350-361, DOI 10.1016/j.jpowsour.2018.01.028.

10. Miao, F.; Shao, C.; Li, X.; Wang, K.; Lu, N.; Liu, Y. Electrospun Carbon Nanofibers/Carbon Nanotubes/Polyaniline Ternary Composites with Enhanced Electrochemical Performance for Flexible Solid-State Supercapacitors. ACS Sustainable Chem. Eng. 2016, 4 (3), 1689-1696, DOI 10.1021/acssuschemeng.5b01631. 11. Wang, H.; Zhu, E.; Yang, J.; Zhou, P.; Sun, D.; Tang, W. Bacterial Cellulose Nanofiber-Supported

Polyaniline

Nanocomposites

with

Flake-Shaped

Morphology

as

Supercapacitor Electrodes. J. Phys. Chem. C. 2012, 116 (24), 13013-13019. DOI 10.1021/jp301099r. 12. Gopakumar, D. A.; Pai, A. R.; Pottathara, Y. B.; Pasquini, D.; Carlos, L. D. M.; Luke, M.; Thomas, S. Cellulose Nanofiber-Based Polyaniline Flexible Papers as Sustainable Microwave Absorbers in the X-Band. ACS. Appl. Mater. Inter. 2018, 10(23), 20032-20043, DOI 10.1021/acsami.8b04549. 13. Rahman, M. M.; Netravali, A. N. Aligned Bacterial Cellulose Arrays as “Green” Nanofibers for

Composite

Materials.

ACS.

Macro.

Lett.

2016,

5(9),

1070-1074,

DOI

10.1021/acsmacrolett.6b00621. 14. Lv, X.; Yang, J.; Feng, C.; Li, Z.; Chen, S.; Xie, M.; Xu, Y. A Bacterial Cellulose-Based Biomimetic Nanofibrous Scaffold with Muscle Cells for Hollow Organ Tissue Engineering. ACS. Biomater. Sci. Eng. 2015, 2 (1), 19-29, DOI 10.1021/acsbiomaterials.5b00259. 15. Wang, S.; Li, T.; Chen, C.; Kong, W.; Zhu, S.; Dai, J. Transparent, Anisotropic Biofilm with Aligned Bacterial Cellulose Nanofibers. Adv. Funct. Mater. 2018, 28 (24), 1707491, DOI 10.1002/adfm.201707491 16. Singhsa, P.; Narain, R.; Manuspiya, H. Bacterial Cellulose Nanocrystals (BCNC) Preparation and Characterization from Three Bacterial Cellulose Sources and Development of Functionalized BCNCs as Nucleic Acid Delivery Systems. ACS. Appl. Nano. Mater. 2017, 1 (1), 209-221, DOI 10.1021/acsanm.7b00105.



17. Marins, J.; Soares, B.; Dahmouche, K.; Ribeiro, S.; Barud, H.; Bonemer, D. Structure and Properties of Conducting Bacterial Cellulose-Polyaniline Nanocomposites. Cellulose. 2011, 18 (5), 1285-1294, DOI 10.1007/s10570-011-9565-4. 18. Alonso, E.; Faria, M.; Mohammadkazemi, F.; Resnik M.; Ferreira, A.; Cordeiro, N. Conductive Bacterial Cellulose-Polyaniline Blends: Influence of the Matrix and Synthesis Conditions. Carbohyd. Polym. 2018, 183, 254-162, DOI 10.1016/j.carbpol.2017.12.025. 19. Hu, W.; Chen, S.; Yang, Z.; Liu, L.; Wang, H. Flexible Electrically Conductive Nanocomposite Membrane Based on Bacterial Cellulose and Polyaniline. J. Phys. Chem. B. 2011, 115 (26), 8453-8457, DOI 10.1021/jp204422v. 20. Lin, Z.; Guan, Z.; Huang, Z. New Bacterial Cellulose/Polyaniline Nanocomposite Film with One Conductive Side Through Constrained Interfacial Polymerization. Ind. Eng. Chem. Res. 2013, 52 (8), 2869-2874, DOI 10.1021/ie303297b. 21. Rogalsky, S.; Bardeau, J. F.; Makhno, S.; Babkina, N.; Tarasyuk, O.; Cherniavska, T. New Proton Conducting Membrane Based on Bacterial Cellulose/Polyaniline Nanocomposite Film Impregnated with Guanidinium-Based Ionic Liquid. Polymer. 2018, 142, 185-195, DOI 10.1016/j.polymer.2018.03.032. 22. Wan, Y.; Li, J.; Yang, Z.; Ao, H.; Xiong, L.; Luo, H. Simultaneously Depositing Polyaniline onto Bacterial Cellulose Nanofibers and Graphene Nanosheets toward Electrically Conductive Nanocomposites. Curr. Appl. Phys. 2018, 18 (8), 933-940, DOI 10.1016/j.cap.2018.05.008. 23. Wang, H.; Leaukosol, N.; He, Z.; Fei, G.; Si, C.; Ni, Y. Microstructure, Distribution and Properties of Conductive Polypyrrole/Cellulose Fiber Composites. Cellulose. 2013, 20 (4), 1587-1601, DOI 10.1007/s10570-013-9945-z. 24. Nascimento, G. M. D.; Constantino, V. R. L.; Landers, R.; Temperini, M. L. A. Spectroscopic Characterization of Polyaniline Formed in the Presence of Montmorillonite Clay. Polymer. 2006, 47 (17), 6131-6139, DOI 10.1016/j.polymer.2006.06.036. 25. Gu, H.; Rapole, S. B.; Sharma, J.; Huang, Y.; Cao, D.; Colorado, H. A. Magnetic polyaniline nanocomposites toward toxic hexavalent chromium removal. RSC Advances. 2012, 2 (29), 11007-11018, DOI 10.1039/c2ra21991c. 26. Qiao, H.; Xu, W.; Chao, M.; Liu, J.; Lei, W.; Zhou, X. Preparation and Performance of Silica/Epoxy Group-Functionalized Bio-Based Elastomer Nanocomposite. Ind. Eng. Chem. Res.


Page 22 of 24

Page 23 of 24 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


2017, 56 (4), 881-889, DOI 10.1021/acs.iecr.6b03517. 27. Luong, N. D.; Korhonen, J. T.; Soininen, A. J.; Ruokolainen, J.; Johansson, L. S.; Seppälä, J. Processable Polyaniline Suspensions through in situ Polymerization onto Nanocellulose. Eur. Polym. 2013, 49 (2), 335-344, DOI 10.1016/j.eurpolymj.2012.10.026. 28. Zhao, S.; Abu-Omar, M. M. Biobased Epoxy Nanocomposites Derived from Lignin-Based Monomers. Biomacromolecules. 2015, 16 (7), 2025-2031, DOI 10.1021/acs.biomac.5b00670. 29. Kim, G.; Rho, Y.; Park, S.; Kim, H.; Son, S.; Kim, H. The Biocompatibility of Self-Assembled Brush Polymers Bearing Glycine Derivatives. Biomaterials. 2010, 31 (14), 3816-3826, DOI 10.1016/j.biomaterials.2010.01.130. 30. Alvi, M. U.; Zulfiqar, S.; Yavuz, C.T.; Kweon, H. S.; Sarwar, M. I. Influence of Aminosilane Coupling Agent on Aromatic Polyamide/Intercalated Clay Nanocomposites. Ind. Eng. Chem. Res. 2013, 52 (21), 6908-6915, DOI 10.1021/ie400463z. 31. Kawai, T.; Ohtsuki, C.; Kamitakahara, M.; Tanihara, M.; Miyazaki, T.; Sakaguchi, Y.; S, Konagaya. Removal of Formaldehyde by Hydroxyapatite Layer Biomimetically Deposited on Polyamide Film. Environ. Sci. Technol. 2006, 40 (13), 4281-4285, DOI 10.1021/es050098n. 32. Sengupta, P. P.; Gloria, J. N.; Amato, D. N.; Amato. D. V.; Patton, D. L.; Murali. B. Utilizing Intrinsic Properties of Polyaniline to Detect Nucleic Acid Hybridization Through UV-Enhanced Electrostatic

Interaction. Biomacromolecules.

2015,

16

(10),

3217-3225,

DOI

10.1021/acs.biomac.5b00935. 33. Liao, Y.; Zhang, C.; Zhang, Y.; Strong, V.; Tang, J.; Li, X. G. Carbon Nanotube/Polyaniline Composite Nanofibers: Facile Synthesis and Chemosensors. Nano. Lett. 2011, 11 (11), 954-959, DOI 10.1021/nl103322b.



Abstract Graphic:

Synopsis: The sustainable bacterial cellulose/polyaniline nanocomposites may have prosperous application in various fields such as the flexible electronic device, antistatic and electromagnetic materials.


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Polyaniline ... - ACS Publications

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