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Article

Electrosprayed Chitosan Nanospheres-Based Films: Evaluating the Effect of Molecular Weight on Physicochemical Properties

by
Bruna Farias
*,
Francisca Rizzi
,
Rafael Gerhardt
,
Eduardo Ribeiro
,
Daiane Dias
,
Tito Roberto Cadaval
and
Luiz Antonio Pinto
School of Chemistry and Food, Federal University of Rio Grande (FURG), km 8 Itália Avenue, Rio Grande 96203-900, Brazil
*
Author to whom correspondence should be addressed.
Coatings 2024, 14(9), 1159; https://doi.org/10.3390/coatings14091159
Submission received: 6 August 2024 / Revised: 27 August 2024 / Accepted: 6 September 2024 / Published: 9 September 2024
(This article belongs to the Special Issue Advances and Trends in Edible Films and Coatings)
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Abstract

:
This study explores the effect of chitosan molecular weight on the formation of chitosan-based films by electrospraying process. The oxidative pathway was employed in chitosan with 220.1 kDa to obtain samples with 124.5 and 52.7 kDa. Both samples of depolymerized chitosan resulted in spheres within electrosprayed chitosan-based films due to a higher deacetylation degree (~85%). The increase in molecular weight (52.7 to 124.5 kDa) resulted in nanospheres (562 nm) within electrosprayed chitosan-based films, enhancing the surface area-to-volume ratio of the material. The electrospraying process maintained the structural integrity and thermal stability of all chitosan-based films while reducing their crystallinity. These findings highlight the impact of chitosan properties, particularly molecular weight, on the physicochemical characteristics of electrosprayed chitosan-based films. For instance, this work provides insights for the application of electrosprayed chitosan-based films in various fields.

1. Introduction

Chitosan is a non–toxic biopolymer composed of residues of 2–acetamido–2–deoxy–β–D–glucopyranose and 2–amino–2–deoxy–β–D–glucopyranose. Industrially, this polysaccharide is produced through the alkaline deacetylation of chitin, which is mainly isolated from crustacean shells and fungal cell walls [1,2]. Among the properties of chitosan, its polyelectrolytic nature (pKa~6.3) stands out. In acidic solutions, the amine groups (–NH2) within the polymer chain become protonated, resulting in the formation of (–NH3)+. Therefore, chitosan can form electrostatic interactions between its positively charged amine groups and different negatively charged compounds [3,4]. Furthermore, chitosan-based nanomaterials have an increased surface area, thereby enhancing the reactivity of the biopolymer. This property makes chitosan attractive for the development of pharmaceutical and food carriers, purification of organic compounds, treatment of wastewater and development of antimicrobial food packaging [5,6,7,8,9,10].
Among chitosan-based nanomaterials, films composed of nanospheres can be developed using electrohydrodynamic techniques such as electrospraying. The effectiveness of this process is influenced by solution parameters, including molecular weight and concentration. These parameters affect the solution regimes and, consequently, the entanglement of polymer chains and the flow behavior of the solution [11,12,13]. The development of nanospheres requires the achievement of Rayleigh instability. This instability occurs prior to the semidilute regime with entanglement. During the electrostatic repulsion of the jet, its surface area increases, while surface tension tends to minimize the jet’s surface area. Therefore, the absence or insufficient amount of entanglement among the polymer chains results in the fragmentation of the jet into droplets, which are attracted to the collector to form micro- or nanospheres. Furthermore, the electrostatic repulsion among the charged droplets is important to prevent their coalescence [14,15].
A previous study has investigated the effect of chitosan molecular weight on the development of microspheres as delivery vehicles for bioactive molecules [16]. However, to the best of our knowledge, no research has been conducted on the development of chitosan nanosphere-based films or examined the effects of molecular weight on their structural, crystallinity and thermal properties. Although it is known that the molecular weight of chitosan influences the solution properties during electrospraying, there is a lack of information in the literature regarding the impact of chitosan molecular weight on electrosprayed chitosan-based films. It should be mentioned that the development of films by electrospraying is an emerging topic [17,18,19]. The electrospraying process allows the deposition of small droplets with electrostatic repulsion among them, resulting in deposition without agglomeration and achieving greater homogeneity [20,21]. For instance, it is pertinent to study the effect of chitosan characteristics, with an emphasis on molecular weight, on the production of films containing spheres by electrospraying. Therefore, this work aimed to investigate how molecular weight influences the fabrication of chitosan-based films composed of spheres and to characterize their physicochemical properties.

2. Materials and Methods

2.1. Material

Chitosan

Chitosan was obtained following methodologies established in earlier studies [22,23,24]. Initially, chitin was isolated from shrimp waste (Penaeus brasiliensis) through a series of processes including demineralization, deproteinization and deodorization. The production of chitosan involved the chemical deacetylation of chitin under specified conditions: chitin particle size (1 mm), NaOH solution-to-chitin ratio (20:1 w v−1), NaOH solution concentration (45%, w v−1) and reaction duration (90 min). Subsequently, chitosan was purified and dried. Moreover, the depolymerization reaction via the oxidative pathway was employed according to previous work to obtain chitosan with different molecular weight values [25]. Chitosan (2%, w v−1) was dissolved in hydrochloric acid solution (0.05 mol L−1) at 25 ± 1 °C, under magnetic stirring (300 rpm) (Fisatom, 752, São Paulo, Brazil) for 12 h. Subsequently, 5 mL of hydrogen peroxide (0.2 mol L−1) was added to the solution at 65 ± 1 °C, under magnetic stirring (300 rpm) (Fisatom, 752, São Paulo, Brazil) for 100 and 8 min. The depolymerized chitosan was then precipitated using sodium hydroxide solution (10%, w v−1) until the pH of 12.5 was achieved, followed by neutralization to pH 7.0 with hydrochloric acid solution (10%, v v−1). Finally, the depolymerized chitosan was washed and separated via centrifugation (Sigma, 6–16, Steinheim, Germany).
The deacetylation degree of chitosan was determined using the potentiometric titration method [26]. The viscosity-average molecular weight (MW) of chitosan was determined using a Cannon–Fenske viscometer (Schott Gerate, GMBH–D65719, Mainz, Germany). Initially, the intrinsic viscosity (η) was calculated using Huggin’s equation, Equation (1). Moreover, the MW was derived through the application of the Mark–Houwink equation, Equation (2).
η S P   c = ( η ) + k ( η ) 2 c
η = K ( M W ) a
where ηSP/c is the reduced viscosity (mL g−1); ηSP is the specific viscosity, which relates the viscosity of chitosan in solution and the viscosity of the solvent (dimensionless); c is the chitosan concentration (g mL−1); k is the Huggins constant (dimensionless); and K and a are constants, which are used depending on the solvent–polymer system (K = 1.81 × 10−3 mL g−1 and a = 0.93) [27].

2.2. Development of Electrosprayed Chitosan-Based Films

The obtained chitosan with different molecular weight values were used to develop electrosprayed chitosan-based films. Therefore, chitosan (5–13%, w v−1) was dissolved in 90% (v v−1) acetic acid solution for 12 h, under stirring (300 rpm) (Fisatom, 752, São Paulo, Brazil) at 25 °C. The chitosan-based films were produced via electrospraying technique (Instor, Viamão, Brazil). Based on initial experiments, the chitosan solution was electrosprayed using a metallic capillary diameter of 0.7 mm, applied voltage of 25 kV, capillary–collector distance of 5 cm and flow rate of 0.02 mL h−1. The chitosan-based films were synthesized at 25 ± 1 °C and relative humidity of 40 ± 1%.

2.3. Morphology of Electrosprayed Chitosan-Based Films

The diameter and surface morphology of chitosan-based films and spheres were analyzed using a scanning electron microscope (SEM) (JEOL, JSM–6610, Akishima-shi, Japan) operating at 10 kV. Before imaging, the samples were coated with a 1 nm layer of gold. The average diameter was calculated by randomly measuring the diameters of 20 individual spheres [28].

2.4. Structural Modifications of Electrosprayed Chitosan-Based Films

Structural changes in the electrosprayed chitosan-based films were analyzed using attenuated total reflectance infrared spectroscopy (ATR–FTIR) (Shimadzu, Prestige 21, Kyoto, Japan). The ATR–FTIR measurements were carried out at 20 °C, encompassing a wavenumber range from 650 to 4000 cm−1 [29].

2.5. Crystallinity of Electrosprayed Chitosan-Based Films

Crystalline modifications in electrosprayed chitosan-based films were assessed through X-ray diffraction (XRD) analysis (Shimadzu, XD3A, Kyoto, Japan). XRD measurements were performed at 40 kV and 40 mA, with a diffraction angle (2θ) from 5° to 90° in increments of 0.05°. The interplanar spacing, denoted as d (Å), was determined using Bragg’s Law (Equation (3)) [25].
n R λ = 2 d   sin θ
where n represents the reflection order (dimensionless), λ the X-ray wavelength (1.5418 Å) and θ the angle of incidence (°).

2.6. Thermal Properties of Electrosprayed Chitosan-Based Films

The thermal properties of electrosprayed chitosan-based films were investigated using both differential scanning calorimetry (DSC) (Shimadzu, DSC–60, Kyoto, Japan) and thermogravimetric analysis (TGA) (Shimadzu, TGA–50, Kyoto, Japan). DSC analysis was used to evaluate physical transitions. It was conducted from 25 °C to 500 °C with a nitrogen flow rate of 50 mL min−1, employing a heating rate of 10 °C min−1 [30]. TGA was used to examinate the thermal stability of the samples. It was performed from 25 °C to 500 °C, under a nitrogen flow rate of 30 mL min−1 at a heating rate of 10 °C min−1 [31].

2.7. Statistical Analysis

The statistical analysis encompassed the comparison of deacetylation degree and molecular weight of chitosan. Mean differences were calculated by Statistica 7.0 software (StatSoft, Tulsa, OK, USA), with significance set at a 95% confidence level (p < 0.05). Graphical representations were created using OriginPro 8.5 software (OriginLab, Northampton, MA, USA).

3. Results and Discussion

3.1. Characterization of Chitosan

Table 1 shows the characteristics of chitosan regarding its molecular weight and deacetylation degree. The chitosan produced under the deacetylation reaction (CH–D) exhibited a higher molecular weight compared to chitosan depolymerized via the oxidative pathway for 8 min (CH–O8) and 100 min (CH–O100). Therefore, the oxidative pathway successfully hydrolyzed a portion of the β–D–(1,4) glycosidic bonds, resulting in significant differences (p < 0.05) in molecular weight among all samples. Moreover, a longer reaction time (100 min) led to the production of low molecular weight chitosan (≤50 kDa). It should be mentioned that obtaining chitosan with different molecular weight values is relevant because this parameter affects chain entanglements and, consequently, the electrospraying process [14].
The degree of deacetylation of CH–D was significantly different (p < 0.05) compared to CH–O8 and CH–O100. Considering that the oxidative pathway is random, it might have cleaved N–acetyl groups, increasing the deacetylation degree of chitosan [25]. It should be argued that a high deacetylation degree is important in electrospraying due to the electrostatic repulsion caused by protonated amino groups (–NH3+) within chitosan structure, which enhances the surface area of the jet. This contributes to Rayleigh instability, which is necessary for forming spheres and preventing their coalescence [16,32].

3.2. Morphology of Electrosprayed Chitosan-Based Films

Figure 1 presents the SEM images of chitosan-based films CH–D and CH–O100. The development of spheres (1.66 ± 0.77 µm) was achieved only at a concentration of 13% (w v−1) for the CH–O100. Nevertheless, for CH–D, a chitosan-based film was only formed at a concentration of 5% (w v−1), which comprised a structure that did not correspond to spheres or fibers. Figure 2 presents the chitosan-based film CH–O8. The development of spheres was possible at both concentrations, 12% (w v−1) and 13% (w v−1), which revealed spheres with diameters of 0.562 ± 0.248 and 2.68 ± 2.09 µm, respectively. The results indicate the importance of high deacetylation degree of chitosan (>80%). Indeed, spheres formation is possible under certain operational conditions, as previously discussed. A minimum amount of ionizable functional groups and polymer concentration is required to achieve a high surface charge density in the jet without polymer chain entanglement. This condition enables jet fragmentation due to Rayleigh instability and electrostatic repulsion of the droplets, which prevents coalescence and results in sphere formation [16,32].
Regarding the effect of chitosan molecular weight, the CH–O8 compared to the CH–O100 may have shown greater overlap among the polymer chains, however, without entanglement. This indicates that a minimum molecular weight provides adequate intermolecular cohesion, which enables the jet to be stretched and elongated without premature breakup, resulting in the formation of spherical particles rather than beads. Therefore, this condition resulted in the formation of spheres at two distinct concentrations. For CH–O8, the reduction in concentration from 13% (w v−1) to 12% (w v−1) may have resulted in greater mobility among the polymer chains. For instance, it could have promoted more stretching of the jet, resulting in smaller droplets and, consequently, the formation of spheres with a reduced diameter. The reduction in spheres diameter is relevant to enhance the access and availability of functional groups within chitosan structure, which can improve the interaction with other compounds in food, pharmaceutical and environmental fields [33,34,35]. Furthermore, all samples presented a production rate of 0.01 g h−1, which can be considered satisfactory according to the literature (0.01–0.02 g h−1) [36,37]. Therefore, due to the smaller diameter, the 12% (w v−1) concentration for the CH–O8 was chosen for further characterizations, along with the CH–O100 (13%, w v−1) and CH–D (5%, w v−1).

3.3. Structural Evaluation of Electrosprayed Chitosan-Based Films

The impact of the electrospraying technique on the structural and molecular characteristics of chitosan-based films was evaluated using ATR–FTIR spectra, which is shown in Figure 3. The spectra revealed that all electrosprayed chitosan-based films displayed typical chitosan peaks, particularly the combined stretching vibrations of O–H and N–H groups, evident as a broader peak in the range of 3440–3120 cm−1. Moreover, the N–H bending vibration (amide II band) and bending vibrations of the C–H bonds in CH2 and CH3 groups were observed at 1540 and 1400 cm−1, respectively. The peak at 1070 cm−1 could be attributed to the stretching vibrations of the C–O–C bridge in the chitosan polysaccharide backbone. Indeed, the difference among the FTIR spectra was the peak at 1630 cm−1 observed in chitosan-based film CH–D (Figure 3c), corresponding to stretching vibrations of the C = O bond within the amide groups (amide I band). This result could be attributed to the lower deacetylation degree of this chitosan (72.5%), resulting in a higher proportion of acetyl groups (–COCH3) compared to other electrosprayed chitosan-based films, CH–O8 and CH–O100 (Figure 3a,b). Therefore, it could be argued that the electrospraying technique maintained the structural stability of all chitosan samples, which is important for further applications requiring their reactivity [25,29,38].

3.4. Crystallinity Evaluation of Electrosprayed Chitosan-Based Films

The XRD analysis was carried out to study the effect of electrospraying technique on the crystalline structure of chitosan-based films, which is shown in Figure 4. The N–acetyl–D–glucosamine and N–glucosamine portions were identified at d = 10.28 Å and d = 6.70 Å, respectively (first and second arrows), which is in agreement with the literature [25,39,40,41]. Moreover, the lack of reflection angles in all samples can suggest a reduction in crystallinity in chitosan-based films after the electrospraying process. This phenomenon may result from the partial substitution of intramolecular hydrogen bonds between O3 and O5 atoms, stabilized by acetyl groups within chitosan chains and by hydrogen bonds between solvent molecules and polymeric chains. In addition, a comparison of diffractograms revealed a pronounced reduction in reflection angles for electrosprayed chitosan-based film CH–O100. This result could be explained considering that the depolymerization reaction occurs preferentially in the crystalline region of chitosan, which also promotes some destabilization of hydrogen bonds among polymeric chains [25]. Therefore, the increase in amorphous character, resulting from reduced ordered structure, can improve the diffusion rate of compounds, heat and fluids. This property can provide advantages in drug delivery systems by improving the wettability and rate of dissolution; in the purification of organic compounds and wastewater treatment by enhancing the diffusion rate of compounds into function groups in adsorption process; and in energy storage by increasing the electrons transfer and conductivity [42,43,44]. However, the enhancement of the amorphous character can also facilitate the diffusion of oxygen and water, which can be detrimental to food packaging applications.

3.5. Thermal Properties of Electrosprayed Chitosan-Based Films

The DSC and TGA analyzes were performed to elucidate physical transitions and thermal stability of electrosprayed chitosan-based films, which are shown in Table 2. The chitosan-based films CH–D and CH–O8 showed the glass transition temperature (Tg = 117 °C), which is in agreement with the literature [2,25]. However, the electrosprayed chitosan-based film CH–O100 showed different Tg (80 °C). This result could be related to the more amorphous nature caused by the depolymerization reaction, as previously discussed. Therefore, the diffusion of solvent molecules into the polymer chain might have been facilitated, allowing the solvent to act as a plasticizer. This process could have broken the intermolecular interactions of the chitosan chains and created free spaces within the polymer chain, thereby increasing the mobility of the polymer chains [45,46]. Moreover, the Tg indicates the transition from glassy to rubbery state. Therefore, above this temperature, there is an increase in molecular mobility, which affects several properties, including mechanical, thermal, electrical and chemical.
The electrosprayed chitosan-based films also showed a relaxation enthalpy (∆HR). This phenomenon could be attributed to the structural relaxation of the amorphous portion of the chitosan samples towards thermodynamic equilibrium at a rate that depends on the temperature and water content [47]. This relaxation state could have been caused by the electrospraying process. The high solvent evaporation rate may have influenced the conformational state of the chitosan, which could have been caused by the reduced distance between the capillary and collector (5 cm) [48,49]. This state may also have been induced by the effect of jet destabilization due to Rayleigh instability, which may impair the molecular orientation of the polymer chains.
Regarding the initial degradation temperature (TID) of electrosprayed chitosan-based films, all samples have shown similar values, without indication of compromised thermal stability. It should be mentioned that the thermal stability of electrosprayed chitosan-based films is important for several applications, such as sterilization process in the biomedical and food fields, enzyme support, energy storage and solar thermal devices [10,50,51,52].

4. Conclusions

This work successfully developed electrosprayed chitosan-based films with different chitosan molecular weight values (220.1; 124.5 and 52.7 kDa). Chitosan depolymerized via the oxidative pathway for 8 min (CH–O8) and 100 min (CH–O100) resulted in electrosprayed chitosan spheres-based films due to a higher deacetylation degree of chitosan (>80%) and higher charge density. CH–O8 resulted in electrosprayed chitosan spheres-based films in more concentrations compared to CH–O100. Therefore, the higher molecular weight (124.5 kDa) could have improved the overlap among the polymer chains, but without reaching entanglement. CH–O8 (12%, w v−1) resulted in a chitosan nanospheres-based film (562 nm), which can improve the reactivity of material. The reduced diameter of nanospheres is relevant to improve the accessibility of functional groups in chitosan. Moreover, the electrospraying process has not compromised the structural integrity of any chitosan-based films. Indeed, all samples maintained the main chitosan functional groups after electrospraying. Furthermore, electrospraying process provoked a reduction in crystallinity of chitosan-based films, which was pronounced by depolymerization reaction over time. In fact, as the depolymerization reaction intensified, the inter-molecular interactions within chitosan were disrupted. In addition, all electrosprayed chitosan-based films have shown thermal stability (≥245 °C). Therefore, this work developed electrosprayed chitosan-based films, which are promising for further applications in pharmaceutical, food and environmental areas.

Author Contributions

Conceptualization, B.F., T.R.C. and L.A.P.; methodology, B.F., T.R.C. and L.A.P.; formal analysis, B.F. and E.R.; investigation, B.F., F.R. and R.G.; resources, D.D., T.R.C. and L.A.P., data curation, B.F. and E.R.; writing—original draft preparation, B.F. and E.R.; writing—review and editing, B.F. and E.R.; visualization, B.F., T.R.C. and L.A.P.; supervision, D.D., T.R.C. and L.A.P., project administration, B.F., funding acquisition, D.D., T.R.C. and L.A.P. All authors have read and agreed to the published version of the manuscript.

Funding

The research was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)/Brazil-Finance Code 001, the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)/Brazil, the Fundação de Amparo à Pesquisa do Estado do RS (FAPERGS)/Brazil and the Secretaria de Desenvolvimento, Ciência e Tecnologia/RS/Brazil (projects DCIT 70/2015 and DCIT 77/2016.

Data Availability Statement

The datasets used during the current study are available from the corresponding author.

Acknowledgments

The authors would like to thank the Nanosul/FURG of the Associate Laboratory of the National System of Laboratories in Nanotechnology (SisNANO)/Brazil, Center for Electron Microscopy of the South Zone (CEME–SUL)/FURG/Brazil and Integrated Analysis Center of the Federal University of Rio Grande (CIA)/FURG/Brazil for research support.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Almajidi, Y.Q.; Ponnusankar, S.; Chaitanya, M.V.N.L.; Marisetti, A.L.; Hsu, C.-Y.; Dhiaa, A.M.; Saadh, M.J.; Pal, Y.; Thabit, R.; Adhab, A.H.; et al. Chitosan-Based Nanofibrous Scaffolds for Biomedical and Pharmaceutical Applications: A Comprehensive Review. Int. J. Biol. Macromol. 2024, 264, 130683. [Google Scholar] [CrossRef] [PubMed]
  2. Ribeiro, E.S.; Machado, B.R.; Farias, B.S.; Santos, L.O.; Duarte, S.H.; Cadaval Junior, T.R.S.; Pinto, L.A.A.; Diaz, P.S. Development of Microstructured Chitosan Nanocapsules with Immobilized Lipase. J. Polym. Environ. 2024, 32, 3627–3639. [Google Scholar] [CrossRef]
  3. Elnaggar, E.M.; Abusaif, M.S.; Abdel-Baky, Y.M.; Ragab, A.; Omer, A.M.; Ibrahim, I.; Ammar, Y.A. Insight into Divergent Chemical Modifications of Chitosan Biopolymer: Review. Int. J. Biol. Macromol. 2024, 277, 134347. [Google Scholar] [CrossRef] [PubMed]
  4. Sultana, T.; Dey, S.C.; Molla, M.A.I.; Hossain, M.R.; Rahman, M.M.; Quddus, M.S.; Moniruzzaman, M.; Shamsuddin, S.M.; Sarker, M. Facile Synthesis of TiO2/Chitosan Nanohybrid for Adsorption-Assisted Rapid Photodegradation of an Azo Dye in Water. React. Kinet. Mech. Catal. 2021, 133, 1121–1139. [Google Scholar] [CrossRef]
  5. Jaworska, M.M.; Antos, D.; Górak, A. Review on the Application of Chitin and Chitosan in Chromatography. React. Funct. Polym. 2020, 152, 104606. [Google Scholar] [CrossRef]
  6. Yang, Y.; Aghbashlo, M.; Gupta, V.K.; Amiri, H.; Pan, J.; Tabatabaei, M.; Rajaei, A. Chitosan Nanocarriers Containing Essential Oils as a Green Strategy to Improve the Functional Properties of Chitosan: A Review. Int. J. Biol. Macromol. 2023, 236, 123954. [Google Scholar] [CrossRef]
  7. Rodrigues, C.; Mello, J.M.M.; Dalcanton, F.; Macuvele, D.L.P.; Padoin, N.; Fiori, M.A.; Soares, C.; Riella, H.G. Mechanical, Thermal and Antimicrobial Properties of Chitosan-Based-Nanocomposite with Potential Applications for Food Packaging. J. Polym. Environ. 2020, 28, 1216–1236. [Google Scholar] [CrossRef]
  8. Araújo, G.M.S.; Rodrigues, J.L.; Yurgel, V.C.; Silva, C.; Paulo, A.M.C.; Loureiro, A.I.S.; Dora, C.L. Designing and Characterization of Curcumin-Loaded Nanotechnological Dressings: A Promising Platform for Skin Burn Treatment. Int. J. Pharm. 2023, 635, 122712. [Google Scholar] [CrossRef]
  9. Jamali, A.A.; Mahar, F.K.; Hussain, N.; Khatri, M.; Ullah, A.; Ahmed, F.; Khatri, Z.; Kim, I.S. Fabrication of Chitosan-β-Cyclodextrin-Fe Nanofibers for the Adsorption of As-III from Aqueous Solution Using a Lab-Scale Filtration System. J. Appl. Polym. Sci. 2023, 140, e54367. [Google Scholar] [CrossRef]
  10. Ribeiro, E.S.; Farias, B.S.; Cadaval Junior, T.R.S.; Pinto, L.A.A.; Diaz, P.S. Chitosan–Based Nanofibers for Enzyme Immobilization. Int. J. Biol. Macromol. 2021, 183, 1959–1970. [Google Scholar] [CrossRef]
  11. Shenoy, S.L.; Bates, W.D.; Frisch, H.L.; Wnek, G.E. Role of Chain Entanglements on Fiber Formation during Electrospinning of Polymer Solutions: Good Solvent, Non-Specific Polymer-Polymer Interaction Limit. Polymer 2005, 46, 3372–3384. [Google Scholar] [CrossRef]
  12. Ramakrishna, S.; Fujihara, K.; Teo, W.E.; Yong, T.; Ma, Z.; Ramaseshan, R. Electrospun Nanofibers: Solving Global Issues. Mater. Today 2006, 9, 40–50. [Google Scholar] [CrossRef]
  13. Bock, N.; Dargaville, T.R.; Woodruff, M.A. Electrospraying of Polymers with Therapeutic Molecules: State of the Art. Prog. Polym. Sci. 2012, 37, 1510–1551. [Google Scholar] [CrossRef]
  14. Farias, B.S.; Cadaval Junior, T.R.S.; Pinto, L.A.A. Chitosan-Functionalized Nanofibers: A Comprehensive Review on Challenges and Prospects for Food Applications. Int. J. Biol. Macromol. 2019, 123, 210–220. [Google Scholar] [CrossRef] [PubMed]
  15. Garg, K.; Bowlin, G.L. Electrospinning Jets and Nanofibrous Structures. Biomicrofluidics 2011, 5, 13403. [Google Scholar] [CrossRef]
  16. Gómez-Mascaraque, L.G.; Sanchez, G.; López-Rubio, A. Impact of Molecular Weight on the Formation of Electrosprayed Chitosan Microcapsules as Delivery Vehicles for Bioactive Compounds. Carbohydr. Polym. 2016, 150, 121–130. [Google Scholar] [CrossRef] [PubMed]
  17. He, Y.; Wang, J.; Fu, X.; Lin, H.; Zhang, W.; Wang, X.; Liu, F. Electrosprayed Thin Film Nanocomposite Polyamide Nanofiltration with Homogeneous Distribution of Nanoparticles for Enhanced Separation Performance. Desalination 2023, 546, 116206. [Google Scholar] [CrossRef]
  18. Nunnenkamp, M.; Nieuwenhuijzen, K.J.H.; Elshof, J.E. Multilayer Films of Exfoliated 2D Oxide Nanosheets by Electrospray Deposition. Sci. Rep. 2022, 12, 8673. [Google Scholar] [CrossRef]
  19. Valdespino-León, M.; Calderón-Domínguez, G.; Salgado-Cruz, M.P.; Rentería-Ortega, M.; Farrera-Rebollo, R.R.; Morales-Sánchez, E.; Gaona-Sánchez, V.A.; Terrazas-Valencia, F. Biodegradable Electrosprayed Pectin Films: An Alternative to Valorize Coffee Mucilage. Waste Biomass Valorization 2021, 12, 2477–2494. [Google Scholar] [CrossRef]
  20. Bodnár, E.; Grifoll, J.; Rosell-Llompart, J. Polymer Solution Electrospraying: A Tool for Engineering Particles and Films with Controlled Morphology. J. Aerosol Sci. 2018, 125, 93–118. [Google Scholar] [CrossRef]
  21. Gaona-Sánchez, V.A.; Calderón-Domínguez, G.; Morales-Sánchez, E.; Chanona-Pérez, J.J.; Velázquez-de la Cruz, G.; Méndez-Méndez, J.V.; Terrés-Rojas, E.; Farrera-Rebollo, R.R. Preparation and Characterisation of Zein Films Obtained by Electrospraying. Food Hydrocoll. 2015, 49, 1–10. [Google Scholar] [CrossRef]
  22. Moura, J.M.; Farias, B.S.; Rodrigues, D.A.S.; Moura, C.M.; Dotto, G.L.; Pinto, L.A.A. Preparation of Chitosan with Different Characteristics and Its Application for Biofilms Production. J. Polym. Environ. 2015, 23, 470–477. [Google Scholar] [CrossRef]
  23. Dotto, G.L.; Souza, V.C.; Moura, J.M.; Moura, C.M.; Pinto, L.A.A. Influence of Drying Techniques on the Characteristics of Chitosan and the Quality of Biopolymer Films. Dry. Technol. 2011, 29, 1784–1791. [Google Scholar] [CrossRef]
  24. Weska, R.F.; Moura, J.M.; Batista, L.M.; Rizzi, J.; Pinto, L.A.A. Optimization of Deacetylation in the Production of Chitosan from Shrimp Wastes: Use of Response Surface Methodology. J. Food Eng. 2007, 80, 749–753. [Google Scholar] [CrossRef]
  25. Farias, B.S.; Grundmann, D.D.R.; Rizzi, F.Z.; Martins, N.S.S.; Cadaval Junior, T.R.S.; Pinto, L.A.A. Production of Low Molecular Weight Chitosan by Acid and Oxidative Pathways: Effect on Physicochemical Properties. Food Res. Int. 2019, 123, 88–94. [Google Scholar] [CrossRef]
  26. Jiang, X.; Chen, L.; Zhong, W. A New Linear Potentiometric Titration Method for the Determination of Deacetylation Degree of Chitosan. Carbohydr. Polym. 2003, 54, 457–463. [Google Scholar] [CrossRef]
  27. Masuelli, M.A. Mark-Houwink Parameters for Aqueous-Soluble Polymers and Biopolymers at Various Temperatures. J. Polym. Biopolym. Phys. Chem. 2014, 2, 37–43. [Google Scholar] [CrossRef]
  28. Goldstein, J.I.; Newbury, D.E.; Michael, J.R.; Ritchie, N.W.M.; Scott, J.H.J.; Joy, D.C. Scanning Electron Microscopy and X-ray Microanalysis; Springer: Berlin/Heidelberg, Germany, 2017. [Google Scholar]
  29. Silverstein, R.W.; Bassler, G.C. Spectrometric Identification of Organic Compounds. J. Chem. Educ. 1962, 39, 546. [Google Scholar] [CrossRef]
  30. ASTM D7426; Standard Test Method for Assignment of the DSC Procedure for Determining Tg of a Polymer or an Elastomeric Compound. American Society for Testing & Material: West Conshohocken, PA, USA, 2013.
  31. ASTM D3850-12; Standard Test Method for Rapid Thermal Degradation of Solid Electrical Insulating Materials By Thermogravimetric Method (TGA). American Society for Testing & Material International: West Conshohocken, PA, USA, 2012.
  32. Burger, C.; Hsiao, B.S.; Chu, B. Nanofibrous Materials and Their Applications. Annu. Rev. Mater. Res. 2006, 36, 333–368. [Google Scholar] [CrossRef]
  33. Lee, S.J.; Gwak, M.A.; Chathuranga, K.; Lee, J.S.; Koo, J.; Park, W.H. Multifunctional Chitosan/Tannic Acid Composite Films with Improved Anti-UV, Antioxidant, and Antimicrobial Properties for Active Food Packaging. Food Hydrocoll. 2023, 136, 108249. [Google Scholar] [CrossRef]
  34. Ahmed, T.A.; Aljaeid, B.M. Preparation, Characterization, and Potential Application of Chitosan, Chitosan Derivatives, and Chitosan Metal Nanoparticles in Pharmaceutical Drug Delivery. Drug Des. Devel Ther. 2016, 10, 483–507. [Google Scholar] [CrossRef]
  35. Shajahan, A.; Shankar, S.; Sathiyaseelan, A.; Narayan, K.S.; Narayanan, V.; Kaviyarasan, V.; Ignacimuthu, S. Comparative Studies of Chitosan and Its Nanoparticles for the Adsorption Efficiency of Various Dyes. Int. J. Biol. Macromol. 2017, 104, 1449–1458. [Google Scholar] [CrossRef]
  36. Morais, A.Í.S.; Vieira, E.G.; Afewerki, S.; Sousa, R.B.; Honorio, L.M.C.; Cambrussi, A.N.C.O.; Santos, J.A.; Bezerra, R.D.S.; Furtini, J.A.O.; Silva-Filho, E.C.; et al. Fabrication of Polymeric Microparticles by Electrospray: The Impact of Experimental Parameters. J. Funct. Biomater. 2020, 11, 4. [Google Scholar] [CrossRef]
  37. Gomez, A.; Bingham, D.; De Juan, L.; Tang, K. Production of Protein Nanoparticles by Electrospray Drying. J. Aerosol Sci. 1998, 29, 561–574. [Google Scholar] [CrossRef]
  38. Pawlak, A.; Mucha, M. Thermogravimetric and FTIR Studies of Chitosan Blends. Thermochim. Acta 2003, 396, 153–166. [Google Scholar] [CrossRef]
  39. Moussout, H.; Ahlafi, H.; Aazza, M.; Bourakhouadar, M. Kinetics and Mechanism of the Thermal Degradation of Biopolymers Chitin and Chitosan Using Thermogravimetric Analysis. Polym. Degrad. Stab. 2016, 130, 1–9. [Google Scholar] [CrossRef]
  40. Zhang, Y.; Xue, C.; Xue, Y.; Gao, R.; Zhang, X. Determination of the Degree of Deacetylation of Chitin and Chitosan by X-Ray Powder Diffraction. Carbohydr. Res. 2005, 340, 1914–1917. [Google Scholar] [CrossRef]
  41. Jayakumar, R.; Tamura, H. Synthesis, Characterization and Thermal Properties of Chitin-g-Poly(ɛ-Caprolactone) Copolymers by Using Chitin Gel. Int. J. Biol. Macromol. 2008, 43, 32–36. [Google Scholar] [CrossRef]
  42. Zhang, J.; Li, Y.; Chen, Z.; Liu, Q.; Chen, Q.; Chen, M. Amorphous Electrode: From Synthesis to Electrochemical Energy Storage. Energy Environ. Mater. 2023, 6, e12573. [Google Scholar] [CrossRef]
  43. Tambe, S.; Jain, D.; Meruva, S.K.; Rongala, G.; Juluri, A.; Nihalani, G.; Mamidi, H.K.; Nukala, P.K.; Bolla, P.K. Recent Advances in Amorphous Solid Dispersions: Preformulation, Formulation Strategies, Technological Advancements and Characterization. Pharmaceutics 2022, 14, 2202. [Google Scholar] [CrossRef]
  44. Stachurski, Z.H. On Structure and Properties of Amorphous Materials. Materials 2011, 4, 1564–1598. [Google Scholar] [CrossRef] [PubMed]
  45. Zhang, Y.; Li, F.; Valenzuela, L.D.; Sammalkorpi, M.; Lutkenhaus, J.L. Effect of Water on the Thermal Transition Observed in Poly(Allylamine Hydrochloride)-Poly(Acrylic Acid) Complexes. Macromolecules 2016, 49, 7563–7570. [Google Scholar] [CrossRef]
  46. Hariri, H.H.; Lehaf, A.M.; Schlenoff, J.B. Mechanical Properties of Osmotically Stressed Polyelectrolyte Complexes and Multilayers: Water as a Plasticizer. Macromolecules 2012, 45, 9364–9372. [Google Scholar] [CrossRef]
  47. Fan, F.; Roos, Y.H. Structural Relaxations of Amorphous Lactose and Lactose-Whey Protein Mixtures. J. Food Eng. 2016, 173, 106–115. [Google Scholar] [CrossRef]
  48. Farias, B.S.; Vidal, É.M.; Ribeiro, N.T.; Silveira, N.; Vaz, B.S.; Kuntzler, S.G.; Morais, M.G.; Cadaval, T.R.S.A.; Pinto, L.A.A. Electrospun Chitosan/Poly(Ethylene Oxide) Nanofibers Applied for the Removal of Glycerol Impurities from Biodiesel Production by Biosorption. J. Mol. Liq. 2018, 268, 365–370. [Google Scholar] [CrossRef]
  49. Ero-Phillips, O.; Jenkins, M.; Stamboulis, A. Tailoring Crystallinity of Electrospun Plla Fibres by Control of Electrospinning Parameters. Polymers 2012, 4, 1331–1348. [Google Scholar] [CrossRef]
  50. Thanisha, F.; Koliyoor, J.; Ismayil; Monteiro, J. Amorphous Magnesium-Doped Chitosan Films as Solid Polymer Electrolytes for Energy Storage Device Applications. Mater. Sci. Eng. B 2024, 301, 117149. [Google Scholar] [CrossRef]
  51. Yang, C.C.; Lo, C.T.; Luo, Y.L.; Venault, A.; Chang, Y. Thermally Stable Bioinert Zwitterionic Sulfobetaine Interfaces Tolerated in the Medical Sterilization Process. ACS Biomater. Sci. Eng. 2021, 7, 1031–1045. [Google Scholar] [CrossRef]
  52. Wang, F.; Wei, D.; Li, Y.; Chen, T.; Mu, P.; Sun, H.; Zhu, Z.; Liang, W.; Li, A. Chitosan/Reduced Graphene Oxide-Modified Spacer Fabric as a Salt-Resistant Solar Absorber for Efficient Solar Steam Generation. J. Mater. Chem. A Mater. 2019, 7, 18311–18317. [Google Scholar] [CrossRef]
Coatings 14 01159 g001
Figure 1. Scanning electron microscope images of electrosprayed chitosan-based films: (a) 13% (m v−1) CH–O100 × 500; (b) 5% (m v−1) CH–D × 500; (c) 13% (m v−1) CH–O100 × 2.500; (d) 5% (m v−1) CH–D × 2.500.
Figure 1. Scanning electron microscope images of electrosprayed chitosan-based films: (a) 13% (m v−1) CH–O100 × 500; (b) 5% (m v−1) CH–D × 500; (c) 13% (m v−1) CH–O100 × 2.500; (d) 5% (m v−1) CH–D × 2.500.
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Coatings 14 01159 g002
Figure 2. Scanning electron microscope images of electrosprayed chitosan-based films CH–O8: (a) 12% (m v−1) × 500; (b) 13% (m v−1) × 500; (c) 12% (m v−1) × 2.500; (d) 13% (m v−1) × 2.500.
Figure 2. Scanning electron microscope images of electrosprayed chitosan-based films CH–O8: (a) 12% (m v−1) × 500; (b) 13% (m v−1) × 500; (c) 12% (m v−1) × 2.500; (d) 13% (m v−1) × 2.500.
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Coatings 14 01159 g003
Figure 3. Attenuated total reflectance infrared spectroscopy spectrum of electrosprayed chitosan-based films: (a) CH–O100; (b) CH–O8; (c) CH–D.
Figure 3. Attenuated total reflectance infrared spectroscopy spectrum of electrosprayed chitosan-based films: (a) CH–O100; (b) CH–O8; (c) CH–D.
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Coatings 14 01159 g004
Figure 4. X-ray diffractograms of electrosprayed chitosan-based films: (a) CH–O100; (b) CH–O8; (c) CH–D.
Figure 4. X-ray diffractograms of electrosprayed chitosan-based films: (a) CH–O100; (b) CH–O8; (c) CH–D.
Coatings 14 01159 g004
Table 1. Characteristics of chitosan.
Table 1. Characteristics of chitosan.
TypeMolecular Weight
(kDa)		Deacetylation Degree (%)
CH–D220.1 ± 3.7 a72.5 ± 3.8 a
CH–O8124.5 ± 2.3 b84.2 ± 0.8 b
CH–O10052.7 ± 1.5 c86.5 ± 0.4 b
Mean value ± standard deviation (n = 3). Small letters with different superscripts in the same column are significantly different (p < 0.05). CH–D: chitosan produced under deacetylation reaction; CH–O8: chitosan depolymerized under oxidative pathway in 8 min; CH–O100: chitosan depolymerized under oxidative pathway in 100 min.
Table 2. Thermal properties of electrosprayed chitosan spheres-based films.
Table 2. Thermal properties of electrosprayed chitosan spheres-based films.
SampleTg
(°C)		∆HR
(J g−1)		TID
(°C)
CH–D117 ± 2247 ± 9275 ± 4
CH–O8117 ± 1197 ± 4245 ± 6
CH–O10080 ± 2397 ± 6260 ± 1
Mean value ± standard deviation (n = 3). CH–D: chitosan produced under deacetylation reaction; CH–O8: chitosan depolymerized under oxidative pathway in 8 min; CH–O100: chitosan depolymerized under oxidative pathway in 100 min; Tg: glass transition temperate; HR: relaxation enthalpy; TID: initial degradation temperature.
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MDPI and ACS Style

Farias, B.; Rizzi, F.; Gerhardt, R.; Ribeiro, E.; Dias, D.; Cadaval, T.R.; Pinto, L.A. Electrosprayed Chitosan Nanospheres-Based Films: Evaluating the Effect of Molecular Weight on Physicochemical Properties. Coatings 2024, 14, 1159. https://doi.org/10.3390/coatings14091159

AMA Style

Farias B, Rizzi F, Gerhardt R, Ribeiro E, Dias D, Cadaval TR, Pinto LA. Electrosprayed Chitosan Nanospheres-Based Films: Evaluating the Effect of Molecular Weight on Physicochemical Properties. Coatings. 2024; 14(9):1159. https://doi.org/10.3390/coatings14091159

Chicago/Turabian Style

Farias, Bruna, Francisca Rizzi, Rafael Gerhardt, Eduardo Ribeiro, Daiane Dias, Tito Roberto Cadaval, and Luiz Antonio Pinto. 2024. "Electrosprayed Chitosan Nanospheres-Based Films: Evaluating the Effect of Molecular Weight on Physicochemical Properties" Coatings 14, no. 9: 1159. https://doi.org/10.3390/coatings14091159

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