Synergistic role of lignin nanoparticles and microfibrillated cellulose in high-barrier coatings for recyclable 3D-formed fiber packaging

In this study, we present a simple one-pot approach to formulate barrier dispersions by combining nanoscaled cellulose and lignin, while harnessing the hydrophobizing effect of tall oil fatty acid (TOFA) modification. Using an in situ solvent-shifting method, unmodified lignin and TOFA-esterified lignin solutions were directly incorporated into aqueous microfibrillated cellulose (MFC) suspensions, enabling the in situ formation of stable lignin nanoparticles (LNPs and TOFA-LNPs) within the MFC matrix. Nanopapers prepared from TOFA-LNP:MFC dispersion with a ratio of 1:2 exhibited excellent barrier properties, with a water vapor transmission rate of 6 g/m²·day (50 % RH, 23 °C), an oil Cobb 1800 value of 0.3 g/m², and a water Cobb 1800 value of 12 g/m². The results demonstrate that TOFA modification of lignin and its incorporation within the MFC matrix as nanoparticles, facilitates the formation of dense, uniform films with strong resistance to moisture and oil. To gain a deeper understanding of the system, surface-sensitive quartz crystal microbalance with dissipation monitoring (QCM-D) and atomic force microscopy (AFM) were used to analyze how the TOFA modification of lignin affected its physicochemical interactions within cellulose fibrils. Furthermore, humidity-controlled QCM-D measurements were used to analyze the effect of lignin-based nanoparticles on the water vapor adsorption behavior of MFC at different relative humidities providing new insights into their barrier performance, explored here for the first time. Finally, the successful application of dispersion coatings onto commercial fiber-based substrates demonstrates their industrial potential. This work introduces a versatile and scalable route to fully biobased coatings, advancing the transition toward circular and sustainable packaging solutions. • One-step solvent-shifting enabled in situ formation of lignin nanoparticles in MFC dispersions. • TOFA-modified lignin nanoparticles enhanced MFC film hydrophobicity. • Humidity-controlled QCM-D revealed reduced water vapor uptake in TOFA-LNP:MFC films. • Scalable, fully biobased coatings demonstrated excellent water and oil barrier for fiber-based substrate.

Microfibrillated cellulose (MFC), TEMPO-pretreated MFC, and hybrid polymer/MFC mix were used for the production of layered films with interesting properties for application in food packaging. The series of samples were prepared from MFC (base layers) using a dispersion-casting method. The same procedure as well as a bar coating technique was applied to form top layers of different basis weights. The barrier properties and formation of the layered films were investigated in relationship to the preparation procedures, combination of layers, and areal weight (basis weight). Characterization was done with respect to oxygen transmission rates (OTR), water vapor transmission rates (WVTR), tensile properties, and contact angles (CA) with water. The produced layered films yielded OTR values of 4 mL m-2 day-1 and fulfilled oxygen barrier requirements for a modified atmosphere packaging (MAP). Hornification of the MFC films, however, occurred during drying, which may result in a loss of the film’s beneficial properties.

Background: Gelatin is a renewable, biodegradable, and inexpensive food polymer. The insufficient mechanical and functional properties of gelatin-based films (GBF) restrict their commercial application in food packaging. This work proposed a facile strategy to prepare an active and robust GBF that has the potential to be used in food packaging. Methods: A strong and active GBF was prepared based on the principle of supramolecular chemistry via the incorporation of gallic acid (GA) as an active crosslinking agent and of microfibrillated cellulose (MFC) as a reinforcing agent. Results: Under the appropriate concentration (1.0 wt%), MFC was evenly dispersed in a gelatin matrix to endow the film with low surface roughness and compact structure. Compared with the GF, the tensile strength and elongation at break of the resultant film reached 6.09 MPa and 213.4%, respectively, representing the corresponding improvement of 12.8% and 27.6%. Besides, a significantly improved water vapor barrier (from 3.985 × 10−8 to 3.894 × 10−8 g·m−1·Pa−1·s−1) and antioxidant activity (from 54.6% to 86.4% for ABTS radical scavenging activity; from 6.0% to 89.1% for DPPH radical scavenging activity) of GBFs were also observed after introducing the aromatic structure of GA and nano-/microfibrils in MFC. Moreover, the UV blocking performance and thermal stability of GGF and GGCFs were also enhanced. Conclusions: this work paves a promising way toward facile preparation of multifunctional GBFs that have great potential to be used in fabricating active and safe food packaging materials for food preservation.

The aim of this work was to develop and characterize microfibrillated cellulose (MFC)/pullulan bionanocomposites. Fourier transform infrared spectroscopy suggested that the affinity between the two polymers resulted in new hydrogen bonding of the nanocomposite materials compared to pristine pullulan. At the same time, an increase in crystallinity was observed proportional to the amount of MFC used, as shown by the X-ray analyses. Accordingly, final films showed improved mechanical properties proportionally to the filler loading, with impressive elastic modulus and tensile strength of ~4.50 GPa and ~60 MPa, respectively, for the sample containing 10 % MFC. However, as demonstrated by the moisture sorption isotherms, the addition of MFC did not help reduce the amount of water adsorbed by the samples. In addition, the oxygen and water vapor permeability data clearly showed that final films still suffered high relative humidity values, whereas their barrier performance toward oxygen was excellent under dry conditions, with O2 permeability coefficients (P′O 2) comparable with those of common high barrier films/coatings. Finally, while the nanocomposites in the form of films had high haze values (from 23 to 40 %), the same nanocomposites in the form of coatings were decidedly more transparent, which suggests that their use as thin layers could be more suitable when the “see-through” capability must be preserved, for example in food packaging applications.

Cellulose from three agri-waste feedstocks—giant cane, Posidonia oceanica seagrass, and coffee silverskin—was processed into aqueous dispersions (1% by weight) of microfibrillated cellulose (MFC) via high-pressure homogenization (HPH) to produce stand-alone films for potential food packaging applications. Rheology, stability, and morphology of dispersions, as well as optical, barrier, mechanical, morphological, and surface properties of the resulting films were evaluated, with Sylvicta® used as a commercial reference. Atomic Force Microscopy (AFM) confirmed successful MFC production (average diameter < 100 nm) after HPH. The dispersions showed good stability (ζ-potential < 30 mV), shear-thinning, and strong-gel behavior (G’/ G’’ ≈ 10). Regardless of cellulose source, the films performed similarly to the commercial solution, including excellent oxygen barrier properties [oxygen transmission rate < 0.01 cm 3 (STP) m −2 day −1 under dry test conditions], high stiffness (Young’s modulus ≈ 7.5 GPa), tensile strength (≈ 85 MPa), and effective UV-shielding. Surface wettability differed: the commercial sample exhibited a higher contact angle (≈ 115°) than the prepared films (≈ 55–95°). Nonetheless, all samples showed initial spreading of the water droplet followed by absorption. This study demonstrates the potential of valorizing agri-food waste and plant residues into sustainable, high-performance cellulosic films for food packaging. The approach supports circular economy strategies and helps reduce the environmental impact of plastics. • Microfibrillated cellulose (MFC) from waste biomasses was mechanically obtained. • MFC films were benchmarked against a cellulosic material on the market. • An in-depth characterization of film-forming dispersion and films was carried out. • The properties of MFC films were comparable to the commercial solution. • MFC films from coffee silverskin outperformed the commercial solution.

Improving barrier and antibacterial properties of chitosan composite films by incorporating lignin nanoparticles and acylated soy protein isolate nanogel

The effect of surface modification of microfibrillated cellulose (MFC) by acid chlorides on the structural and thermomechanical properties of biopolyamide 4.10 nanocomposites

Guar gum based flexible packaging material with an active surface reinforced by litchi shell derived micro fibrillated cellulose and halloysite nanotubes

In order to explore the possibility of polyvinyl alcohol (PVA) reinforced by mixture of chitin nanofibers (ChNFs) and microfibrillated cellulose (MFC) instead of a single reinforcing phase, mechanical properties of PVA based hybrid nanocomposites reinforced with combination of ChNFs and MFC in various mixing ratios were investigated. For comparison, two different experiments were conducted to prepare nanocomposite films by casting technical processing, where ratios of ChNFs to MFC were mixed varying from 1:0, 4:1, 3:2, 1:1, 2:3, 1:4, and 0:1 in both projects, while in Project 1 the weights of PVA and ChNFs were always kept constant and the weight of PVA only was kept constant in Project 2. The results were as follows: (1) The hybrid ternary nanocomposites acquired the highest Young’s modulus and tensile strength when ratio of ChNFs to MFC was 1:1, which exhibited higher Young’s modulus and higher tensile strength than PVA/ChNFs composites, but delivered higher Young’s modulus and similar tensile strength comparing to PVA/MFC composites; (2) Aggregations and voids inside nanocomposites were detrimental to mechanical properties of PVA based hybrid nanocomposites. In some industries such as food packing, PVA based hybrid nanocomposites at mixing ratio 1:1 of ChNFs to MFC are applied presumably with ChNFs partly instead of MFC in the future.

Phase separation of co-solvent promotes multiple bio-nanomaterials conversion from natural lignocellulose

Extraction and physiochemical characterization of micro-fibrillated cellulose based composite biofilm derived from Aegle marmelos fruit shells waste for packaging applications supported by in-silico docking studies.

Starch-based materials seem to be an excellent alternative for conventional plastics used in various applications. Microfibralted cellulose can be used to improve the surface properties of starch-based materials. This study aims to analyze the surface properties of starch-microfibrillated cellulose materials. The surface properties of films were evaluated by ATR-FTIR, surface roughness, water wettability, and surface free energy. The surface homogeneity between corn starch and microfibrillated cellulose (MFC) fibers was confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Microscopic analyses of the film surfaces confirm good compatibility of starch and MFC. The addition of MFC increased the surface roughness and polarity of developed starch/MFC materials. The surface roughness parameter has increased from 1.44 ± 0.59 to 2.32 ± 1.13 for pure starch-based materials and starch/MFC material with the highest MFC content. The WCA contact angle has decreased from 70.3 ± 2.4 to 39.1 ± 1.0°, while the surface free energy is 46.2 ± 3.4 to 66.2 ± 1.5 mJ·m-2, respectively. The findings of this study present that surface structure starch/MFC films exhibit homogeneity, which would be helpful in the application of MFC/starch materials for biodegradable packaging purposes.

The industry and consumers are focusing more and more on the development of biodegradable and lightweight food-packaging materials, which could better preserve the quality of the food and improve its shelf-life. In an attempt to meet these requirements, this study presents a novel bio-substrate able to contain active bio-molecules for future food-packaging applications. Based on a paperboard substrate, the development of an antibacterial bio-packaging material is, therein, achieved using a chlorhexidine digluconate (CHX) solution as a model of an antibacterial molecule, mixed with microfibrillated cellulose (MFC) and used as coating onto paperboard samples. AFM and FE-SEM analyses were performed to underline the nanoporous MFC network able to trap and to progressively release the CHX molecules. The release study of CHX was conducted in an aqueous medium and showed a lower proportion (20%) of CHX released when using MFC. This led to the constant release of low amounts of CHX over 40h. Antibacterial tests were carried out to assess the preservation of the antibacterial activity of the samples after the release studies. Samples remained active against Bacillus subtilis, with better results being obtained when MFC was used. The preservation of the quality of a model food was finally evaluated paving the way for future promising applications in the food packaging industry.

Regenerated silk fibroin (SF) and microfibrillated cellulose (MFC) offer sustainable options as the next generation of green materials based on their desirable properties for multiple applications, also, can be obtained from underutilized side streams in other industries. To date, the SF-MFC composites manufacture relies on multiple steps and cross-linking reactions, which increase their cost and footprint. We propose a sustainable and green alternative for the composite fabrication by simply inducing secondary structure formation of SF on MFC induced through methanol (MeOH) post-treatment. Molecular interactions between MFC and SF were investigated through charge density and quartz crystal microbalance experiments to determine their self-assembly mechanisms, which showed that the SF tended to adsorb on MFC without hindering its capacity to form β-sheet structures when immersed in MeOH. This methodology allowed the formation of homogeneous cryogels with low weight, good dimensional stability, and high relative porosity without the use of external agents. Graphical abstract Impact statement The current high demand for bio-based materials formed through green processing is challenging for the development of versatile composites from abundant and sustainable sources. These new materials should not compete with food sources, be economically feasible, decrease carbon emissions, and provide reproducible materials properties and behaviors. This article presents a processing technique to produce silk and cellulose cryogels using only the inherent chemical properties of the bio-based polymers. The materials used were isolated from undervalued sources, such as discarded silk and sustainably harvested wood feedstocks, adding value to the producers. The self-assembled composites produced and characterized in this study exhibited properties suitable for several high-value applications due to their high porosity, thermal and dimensional stability, and water compatibility.

This article describes the preparation of novel aqueous spongy foams that are composed of three-dimensionally distributed wood-fiber networks stabilized with nanofibrillate cellulose (NFC) and/or microfibrillated cellulose (MFC). The free standing aqueous spongy foams were prepared with the entrapment of NFC and/or MFC—stabilized air-in-water (A/W) capillary foams using “gel trapping technique”. The stability of spongy foams could be controlled by manipulating the volume fraction of NFC and/or MFC and a secondary liquid immiscible with the continuous phase of the NFC and/or MFC suspension. Possible morphology and mechanical distribution of NFC and/or MFC within spongy foams were verified with optical microscope, SEM, and functional load-bearing method. Owing to three-dimensionally dispersed wood-fiber structure, ultra-lightweight (0.01–0.06 g/cm3), high porosity (>90%), and microporous (10–80 μm), the NFC and/or MFC reinforced spongy foams, improved compressional strength-vertical direction obviously, from 0.0 to more than 13.78 kPa.