Fibrous Microstructure Research Articles

The ultrastructural and morphological characteristics of the anterior cruciate ligament of the pig: a study using 7.0-Tesla diffusion tensor imaging.

Diffusion tensor imaging research on the anterior cruciate ligament (ACL) is limited, and no study has revealed the ACL fibrous microstructure by 7.0-Tesla magnetic resonance imaging. Therefore, we used magnetic resonance imaging to assess the ACL. Eight porcine ACLs were investigated by diffusion tensor imaging. Imaging was performed with a 7.0-Tesla scanner using a diffusion-weighted two-dimensional spin-echo echo-planar imaging pulse sequence optimised for muscle. The diffusion tensor eigenparameters, fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were used for bones and muscles. Three-dimensional projection maps of the principal eigenvectors were plotted to visualise the microstructure. The mean FA and ADC for the ACL were 0.27 ± 0.079 and 0.0012 ± 0.0005, respectively. There were no significant differences between the values in the proximal and distal portions . However, the ADC was smaller in the centre than on the sides (0.0015 ± 0.0007), and the mean FA was larger in the centre than on the sides (0.42 ± 0.23). The ACL fibres were parallel on the proximal and distal sides but interweaved in the centre. These findings may be beneficial for artificial ligaments.

Influence of the Nanostitch Sensor Embedment on the Fibrous Microstructure of Glass Fiber Prepreg Laminates.

Changes in the fibrous microstructure in glass fiber/epoxy prepreg quasi-isotropic laminates after the introduction of embedded sensors in the form of "nanostitch" as interleaves are investigated using 3D imaging with synchrotron radiation computer tomography (SRCT). Nanostitch interfaces are created by aligned carbon nanotubes (CNTs) with two different morphologies. The laminates are fabricated using an autoclave. The investigated microstructural features include: thickness variability of the plies and laminate, resin rich gaps at the interfaces, presence of voids, and misorientation of plies and misalignment of fibers deep inside the plies and close to the ply interfaces. The analysis of the SRCT images, at a resolution of 0.65 µm, shows the following: (1) the laminate preserves its thickness, with a resin/CNT-rich gap of ~5 µm created at the interface and the plies compacted by nano-capillarity; (2) there are no voids with sizes over 1-2 µm both in the baseline and nanostitched laminates; (3) the misorientation of plies (the in-plane difference of the average fiber direction from the nominal ply angle) is under 2°; (4) the misalignment (standard deviation of fiber orientations) has the same characteristics in the baseline and nanostitched laminates: it is in the range of 1.5°-3° in-plane and 2°-4° out-of-plane; the misalignment close to interfaces is increased in comparison with the misalignment deep within plies by ~1°. We conclude that the embedment of the nanostitch sensor does not alter the microstructural parameters of the laminate.

Magnetically‐Assisted 3D Bioprinting of Anisotropic Tissue‐Mimetic Constructs

AbstractRecreating the extracellular matrix organization and cellular patterns of anisotropic tissues in bioengineered constructs remains a significant biofabrication challenge. Magnetically‐assisted 3D bioprinting strategies can be exploited to fabricate biomimetic scaffolding systems, but they fail to provide control over the distribution of magnetic materials incorporated in the bioinks while preserving the fidelity of the designed composites. To overcome this dichotomy, the concepts of magnetically‐ and matrix‐assisted 3D bioprinting are combined here. By allowing low viscosity bioinks to remain uncrosslinked after printing, this approach enables the arrangement of incorporated magnetically‐responsive microfibers without compromising the resolution of printed structures before inducing their solidification. Moreover, the fine design of these magnetic microfillers allows the use of low inorganic contents and weak magnetic field strengths, minimizing the potentially associated risks. This strategy is evaluated for tendon tissue engineering purposes, demonstrating that the synergy between the biochemical and biophysical cues stemming from a tendon‐like anisotropic fibrous microstructure, combined with remote magneto‐mechanical stimulation during in vitro maturation, is effective on directing the fate of the encapsulated human adipose‐derived stem cells toward tenogenic phenotype. In summary, the developed strategy allows the fabrication of anisotropic high‐resolution magnetic composites with remote stimulation functionalities, opening new horizons for tissue engineering applications.

Hot Compression Deformation Behavior and Microstructure of As-Cast and Homogenized AA2195 Al-Li Alloy

To understand the effect of the initial state of AA2195 Al-Li alloy on the forming process, as-cast and homogenized ingots were compressed by using a Gleeble-3150 thermo-mechanical simulator at different temperatures (360–480 °C) and strain rates (0.01–10 s−1). The hot compression deformation behaviors and microstructural characteristics of the two types of ingots were systematically investigated. The as-cast alloy possessed a better hot compressibility with higher power dissipation efficiency and lower rheological stress than the homogenized alloy under the same deformation conditions. When the temperature was increased above 450 °C, all the alloys showed similar rheological curves. Based on the rheological stress curves, processing maps for the as-cast (AC) and homogenized (HG) alloys were established, and optimal processing domains were identified. In addition, the homogenized alloys were dominated by a fibrous microstructure during deformation, whereas the as-cast alloy produced fine crystals at low temperature (360 °C) and equiaxed crystals at high temperature (480 °C). Our results show that it is possible to use the as-cast 2195 Al-Li alloy as the initial billet to get complicated components. This is attributed to the dispersed eutectic phases, which can provide more nucleation sites for Dynamic Recrystallization (DRX) and Dynamic Recovery (DRV) during hot deformation.

Shear-induced structuring of phase-separated sodium caseinate - sodium alginate blends using extrusion-based 3D printing: Creation of anisotropic aligned micron-size fibrous structures and macroscale filament bundles

3D food printing is considered a promising method to prepare personalized foods having unique macroscopic design and composition. It is still challenging to create 3D printed foods with tailored microstructure, e.g. fibrous microstructures, to print meat-like foods. In this study we investigated the preparation of 3D printed model food gels that have macro- and microscale aligned fibrous structures using sodium caseinate - sodium alginate (SC/SA) blends with extrusion-based printing. A bath containing an agar fluid gel was used to allow precise deposition and solidification of the SC/SA blend after the printing process. Besides, the influences of nozzle type and printing speeds on texture were assessed. We succesfully created aligned micron-size fibrous structures and macroscale aligned filament bundles. Filaments extruded using tapered nozzles had finer fibrous structures compared to those extruded using straight nozzles. Both printing speed and nozzle type significantly influenced Young's moduli of 3D printed model food gels. A higher printing speed resulted in smaller Young's moduli of individual printed filaments. This study shows that anisotropic structures can be created by extrusion-based 3D printing of phase-separated sodium caseinate - sodium alginate blends. The results of this study might become relevant when striving for meat analogues made by 3D-printing.

Bioinspired polypyrrole based fibrillary artificial muscle with actuation and intrinsic sensing capabilities

A non-conventional, bioinspired device based on polypyrrole coated electrospun fibrous microstructures, which simultaneously works as artificial muscle and mechanical sensor is reported. Fibrous morphology is preferred due to its high active surface which can improve the actuation/sensing properties, its preparation still being challenging. Thus, a simple fabrication algorithm based on electrospinning, sputtering deposition and electrochemical polymerization produced electroactive aligned ribbon meshes with analogous characteristics as natural muscle fibers. These can simultaneously generate a movement (by applying an electric current/potential) and sense the effort of holding weights (by measuring the potential/current while holding objects up to 21.1 mg). Electroactivity was consisting in a fast bending/curling motion, depending on the fiber strip width. The amplitude of the movement decreases by increasing the load, a behavior similar with natural muscles. Moreover, when different weights were hung on the device, it senses the load modification, demonstrating a sensitivity of about 7 mV/mg for oxidation and − 4 mV/mg for reduction. These results are important since simultaneous actuation and sensitivity are essential for complex activity. Such devices with multiple functionalities can open new possibilities of applications as e.g. smart prosthesis or lifelike robots.

How the Nonwoven Polymer Volume Microstructure Is Transformed under Tension in an Aqueous Environment.

The fibrous porous structure of polymers can mimic the extracellular matrix of the native tissue, therefore such polymers have a good potential for use in regenerative medicine. Organs and tissues within the body exhibit different mechanical properties depending on their functionality, thus artificial scaffolds should have mechanical behaviors similar to the extracellular matrix in conditions like living organisms, primarily in aqueous media. Several methods have been investigated in aquatic environments, including noninvasive techniques based on ultrasonic focused beams for biological objectives. In this study we explored the tensile behavior of poly(L-lactide) nonwoven polymer scaffolds using high-frequency ultrasound microscopy combined with a horizontal testing machine, which provided a visualization of the reorganization and transformation of the dynamic volume microstructure. The mechanisms of unwinding, elongation, orientation, and deformation of polymer fibers under uniaxial tension were revealed. We observed an association between the lined plastic deformation from 100 to 400% and the formation of multiple necks in the fibers, which caused stress relaxation and significant rarefaction of the fibrous microstructure. It was shown that both peaks on the stress–strain curve corresponded to the microstructure of aligned fibers in terms of initial diameter and thinning fibers. We discuss the possible influence of these microstructure transformations on cell behavior.

Preparation of CO2 -Based Cationic Polycarbonate/Polyacrylonitrile Nanofibers with an Optimal Fibrous Microstructure for Antibacterial Applications.

Utilizing CO2 as one of the monomer resources, poly(vinylcyclohexene carbonates) (PVCHCs) are used as the precursor for preparing cationic PVCHCs (CPVCHCs) via thiol-ene click functionalization. Through the functionalization, CPVCHC-43 with a tertiary amine density of 43% relative to the backbone is able to display a significantly antibacterial ability against Staphylococcus aureus (S. aureus). Blending CPVCHC-43 with polyacrylonitrile (PAN), CPVCHC/PAN nanofiber meshes (NFMs) have been successfully prepared by electrospinning. More importantly, two crucial fibrous structural factors including CPVCHC/PAN weight ratio and fiber diameter have been systematically investigated for the effects on the antibacterial performance of the NFMs. Sequentially, a quaternization treatment has been employed on the NFMs with an optimal fibrous structure to enhance the antibacterial ability. The resulting quaternized NFMs have demonstrated the great biocidal effects against Gram-positive and Gram-negative bacteria. Moreover, the excellent biocompatibility of the quaternized NFMs have also been thoroughly evaluated and verified.

Effects of Deep Rolling on the Microstructure Modification and Fatigue Life of 35Cr2Ni4MoA Bolt Threads

Stress concentration on a bolt thread, resulting from its own special shape, poses a threat to the fatigue strength of the bolt, which directly affects the safety and reliability of aircraft. In this paper, deep rolling was applied to a bolt thread to improve its fatigue resistance. The properties of the plastic deformation layer, including the surface morphology, microstructure, hardness, and residual stress, as well as the fatigue life of the bolt, were characterized by means of SEM, white light interferometer, EBSD, and fatigue tests. The results showed that the surface roughness of the bottom of the thread was reduced to 0.255 μm, and a plastic deformation layer of about 300 μm in depth was formed after rolling. A more compact streamlined fibrous microstructure, composed of refined grains, with increased dislocation density and hardness and decreased tensile residual stress, was formed in the plastic deformation layer. The fatigue life of the bolts after rolling increased by about 113%, evidencing the comprehensive result of these microstructure modifications.

Investigating liquid‐fronts during spontaneous imbibition of liquids in industrial wicks. Part II: Validation by DNS

AbstractTo validate the experimental results of Part‐1, we conducted a two‐phase flow simulation of imbibition of a wetting liquid through 2D microstructures made of ellipses of varying aspect ratios. The flow simulation in the particulate microstructures, characterized by low (ellipse) aspect ratio, produced somewhat even micro‐fronts, thus replicating the sharp fronts at the visual (macroscopic) scale observed in Part‐1. Whereas simulations in the fibrous microstructures produced highly uneven micro‐fronts, suggesting the formation of semi‐sharp or diffuse visual fronts. Increasing the porosity from 50% to 70% resulted in solid‐phase clustering and led to further increase in the unevenness of micro‐fronts, pointing to purely diffuse visual fronts. The evolution of the saturation plots along the flow direction, obtained from area‐averaging of fluid‐distribution plots, pointed to diffusing of sharp fronts with time. The predictions matched our previous experimental and numerical observations, that is, the particulate media create sharp fronts while the fibrous media create semi‐sharp/diffuse fronts.

An approach to improve the microstructure and mechanical properties: A hybrid manufacturing of laser directed energy deposition and shot peening

As one of the most popular additive manufacturing technologies, laser directed energy deposition (LDED) has been extensively and deeply studied to improve the microstructure and properties of formed materials. Hybrid additive manufacturing(HAM) of LDED and shot peening is an innovative technology that combines the principle of surface strengthening and additive manufacturing. It can improve the mechanical properties and optimize the microstructure of the formed materials by strengthening the surface layer-by-layer. In this paper, the phase, oxygen content, microstructure, tensile properties, hardness and fracture morphology of the samples formed by LDED and HAM are compared. It is found that the mechanical properties of the forming samples are significantly improved by HAM, and the yield strength, ultimate tensile strength and average hardness are increased by 53%, 12% and 7%, respectively. Meanwhile, the microstructure of the sample is improved, some of the coarse columnar grains are refined, the heterogeneity of grain size is reduced, and the fibrous microstructure between layers is reduced. The hybrid additive manufacturing of LDED and shot peening can achieve high efficiency and high quality integrated manufacturing of forming parts, which is expected to promote its efficiency and applicability in practical cases in the future.

Deep origin of the crossed‐lamellar microstructure in early Cambrian molluscs

AbstractAragonitic crossed‐lamellar (CL) is one of the most commonly formed and extensively studied molluscan shell microstructures, yet its origin and early evolution within the Mollusca remains poorly understood. Here, a primitive CL microstructure from one of the oldest gastropods, Pelagiella madianensis, and the problematic hyolith Cupitheca sp. of the Cambrian Series 2 Xinji Formation on the North China Platform, was investigated. In P. madianensis, detailed characterization has revealed a typical four‐ordered hierarchical organization of aragonitic crystallites, and a thick layer of organic membranes surrounding its first‐order lamellae. A transitional fibrous microstructure was observed between the outer CL and inner foliated aragonite structural layers. In Cupitheca sp., only the first and second‐order lamellae were visible due to preservation limitations, and the first‐order lamellae were extremely irregular in shape and size, which is consistent with modern representatives. This study demonstrates that the capability to construct highly‐mineralized intricate shells was acquired in early Cambrian stem‐group gastropods. The CL microstructure first emerged in the early Cambrian and as a basal synapomorphic trait in total‐group molluscs. Moreover, presence of the CL microstructure in problematic lophotrochozoans (i.e. hyoliths) is confirmed. This study contributes to a more complete picture of the evolutionary origin and architectural diversity of biomineralized mollusc shells during the Cambrian explosion, and strengthens the phylogenetic links between hyoliths and molluscs.

Decellularized Periosteum-Derived Hydrogels Promote the Proliferation, Migration and Osteogenic Differentiation of Human Umbilical Cord Mesenchymal Stem Cells.

Human umbilical cord mesenchymal stem cells (hUCMSCs) are promising for bone tissue engineering, which have a non-invasive harvesting process, high cell yield, favorable proliferation capacity, and low immunogenicity. However, the osteogenic efficacy of hUCMSCs is relatively lower than that of bone marrow mesenchymal stem cells (BMSCs). Hydrogels from decellularized extracellular matrix (dECM) preserve the biological compositions and functions of natural ECM, which can provide tissue-specific cues to regulate phenotypic expression and cell fate. It is unknown, however, whether hydrogels from periosteum can serve as pro-osteogenic carriers of hUCMSCs. Herein, a decellularized periosteum-derived hydrogel (dPH) was fabricated to reveal the effects of periosteum-specific cues on the bioactivities of hUCMSCs. A widely used non-bone/periosteum-derived ECM hydrogel product, Matrigel, was used as the control group. After decellularization, the absence of nuclei in the histological analysis indicated a successful removal of cellular components, which was also confirmed by DNA content quantification. The storage modulus of dPH increased (from 164.49 ± 29.92 Pa to 855.20 ± 20.67 Pa) with increasing concentration (from 0.5% to 1%). With a highly porous, fibrous microstructure, dPH had a more hydrophilic surface than Matrigel, of which the water contact angle reduced 62.62 ± 0.04%. Furthermore, dPH prominently promoted the initial cellular spreading with a significantly higher cell surface area (1.47-fold), cell spreading length (1.45-fold) and proliferation (approximately 1.05–1.13-fold) of hUCMSCs than those of Matrigel. Additionally, dPH was conducive to cell migration, whereas no cells migrated to Matrigel in the Transwell model. Compared with those of the Matrigel group, the osteogenesis-related genes expression levels (runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN)) and mineralized matrix formation (9.74-fold) of the hUCMSCs significantly increased in the dPH group. Our study indicated that dPH could provide a pro-osteogenic microenvironment for hUCMSCs, thereby revealing a promising application potential to repair bone defects.

Optimizing mechanical property of spray formed Al-Zn-Mg-Cu alloy by combination of homogenization and warm-rolling

Effect of homogenization and warm-rolling on the mechanical properties of Al-11.38Zn-2.45Mg-1.1Cu-0.13Zr-0.1Fe (wt. %) alloy fabricated by spray forming technology was studied by scanning electron microscopy (SEM), electron back-scatter diffraction (EBSD), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The results indicate that the combination of homogenization and warm-rolling exhibit significantly potential for increasing the mechanical properties of the spray formed alloy. The introduction of two-step homogenization process can promote the precipitation of substantial amount of Al3Zr dispersoids, which provide the Orowan strengthening and inhibit recrystallization of the alloy. The warm-rolling at 200 °C produces a large number of dislocations, which not only provide strain hardening, but also promote the precipitation of η’ phase during aging treatment. Besides, the relatively low temperature rolling combined with Al3Zr dispersoids can avoid dynamic recrystallization and thus maintain fibrous microstructure of the alloy. An ultrahigh strength (YS = 868.9 ± 1.6 MPa, UTS = 878.6 ± 2.8 MPa, respectively) is achieved for the alloy due to synergistic effect of homogenization and warm-rolling.

A constitutive model for fibrous tissues with cross-linked collagen fibers including dispersion — With an analysis of the Poynting effect

The present work deals with cross-links in collagenous tissues and proposes a planar continuum model for large strains to mechanically characterize, for example, the well-known stiffening effect associated with the presence of these cross-links. A key novelty of the paper is the consideration of dispersed fibers connected by randomly distributed cross-links. The model is essentially based on two mechanisms: (i) a fiber dispersion-induced cross-link dispersion and (ii) a fiber-independent cross-link dispersion connecting two arbitrary parallel fibers of the sample space. Within the framework of the generalized structure tensors, we derive appropriate invariants that enter the stored-energy function, taking into account the stiffness and relative orientation of the cross-links and the cross-link-fiber interaction. To illustrate the power of the proposed model, we first consider uniaxial tension and simple shear. We investigate the influence of different cross-link configurations on the stress response. In particular, we are interested in simple shear and the sign of the normal stress perpendicular to the shear planes, which is referred to as the Poynting effect. We show that the cross-links have a significant impact on the normal stress considered. This may provide a deeper insight into the microstructural mechanisms in semi-flexible biopolymer gels that are responsible for the tendency, in simple shear, of the top and bottom faces to approach each other. Finally, we investigate the Poynting effect that occurs in a circular hollow cylinder under pure torsion, i.e. how the axial normal force correlates with the cross-linked fibrous microstructure of the specimen.

Deep learning accelerated prediction of the permeability of fibrous microstructures

Permeability of fibrous microstructures is a key material property for predicting the mold fill times and resin flow path during composite manufacturing. In this work, we report an efficient approach to predict the permeability of 3D microstructures from deep learning based permeability predictions of 2D cross-sections combined via a circuit analogy. After validating the network’s predictions in 2D and extending it to 3D, we investigate its capabilities for handling images of various sizes obtained from virtual and real microstructures. More than 90% of 2D predictions is within ± 30% of their counterparts obtained via flow simulations, similarly for 3D transverse permeability predictions, while in 3D case computational time is reduced from several thousands of seconds to less than 10 s. This work provides a robust and efficient framework for characterizing the permeability of fibrous microstructures and paves the way for extending this capability to estimate the permeability of fabric mesostructures.

HA/HDPE Reinforced with MWCNTs for Bone Reconstruction and Replacement Application

The objective of this study is to demonstrate how the effect of adding multi-walled carbon nanotubes (MWCNTs) nanoparticles to the (Hydroxyapatite /High-density polyethylene) bio-composites. In this investigation, the samples with various percentages of (MWCNTs) were fabricated by a hot-press technique. The morphological characteristics, roughness of the surface and thermal properties of the bio-composite samples (HA/HDPE/MWCNTs) were investigated. The excellent homo-geneous distribution of the internal fibrous network and microstructure arrangements were among the most prominent characteristics obtained through FE-SEM and AFM examinations. The degree of crystallinity showed that the (MWCNTs) additives enhance by an increase of approximately (35%), compared with pure sample (without addition MWCNTs). Based on the experimental results obtained, the fabrication of the presented bio-composites sample exhibited the excellent characteristics that make them promising material for biomedical application as a substitute material for hard tissue likes bone reconstruction.

Mechanical and histological characteristics of aortic dissection tissues

Aims: This study investigated the association between the macroscopic mechanical response of aortic dissection (AoD) flap, its fibre features, and patient physiological features and clinical presentations.Methods: Uniaxial test was performed with tissue strips in both circumferential and longitudinal directions from 35 patients with (AoD:CC) and without (AoD:w/oCC) cerebral/coronary complications, and 19 patients with rheumatic or valve-related heart diseases (RH). A Bayesian inference framework was used to estimate the expectation of material constants (C1, D1, and D2) of the modified Mooney-Rivlin strain energy density function. Histological examination was used to visualise the elastin and collagen in the tissue strips and image processing was performed to quantify their area percentages, fibre misalignment and waviness.Results: The elastin area percentage was negatively associated with age (p = 0.008), while collagen increased about 6% from age 40 to 70 (p = 0.03). Elastin fibre was less dispersed and wavier in old patients and no significant association was found between patient age and collagen fibre dispersion or waviness. Features of fibrous microstructures, either elastin or collagen, were comparable between AoD:CC and AoD:w/oCC group. Elastin and collagen area percentages were positively correlated with C1 and D2, respectively, while the elastin and collagen waviness were negatively correlated with C1 and D2, respectively. Elastin dispersion was negatively correlated to D2. Multivariate analysis showed that D2 was an effective parameter which could differentiate patient groups with different age and clinical presentations, as well as the direction of tissue strip.Conclusion: Fibre dispersion and waviness in the aortic dissection flap changed with patient age and clinical presentations, and these can be captured by the material constants in the strain energy density function. Statement of significanceAortic dissection (AoD) is a severe cardiovascular disease. Understanding the mechanical property of intimal flap is essential for its risk evaluation. In this study, mechanical testing and histology examination were combined to quantify the relationship between mechanical presentations and microstructure features. A Bayesian inference framework was employed to estimate the expectation of the material constants in the modified Mooney-Rivlin constitutive equation. It was found that fibre dispersion and waviness in the AoD flap changed with patient age and clinical presentations, and these could be captured by the material constants. This study firstly demonstrated that the expectation of material constants can be used to characterise tissue microstructures and differentiate patients with different clinical presentations.

Microstructures and mechanical properties of V–V3Si eutectic composites

Abstract V–V3Si eutectic alloys were directionally solidified in a high temperature optical floating zone furnace. Depending on the solidification conditions, several microstructures were observed, such as well-aligned broken lamellar, fibrous, or cellular microstructures. The interphase spacings increased with decreasing solidification rates in agreement with the Jackson-Hunt theory. The mechanical properties of the individual phases were investigated by nanoindentation. It was found that the modulus and nanoindentation hardness of V3Si are 214 and 13.8 GPa, respectively, and those of the V solid-solution are 165 and 3.4 GPa, respectively. The high-temperature strength was examined by tensile testing at elevated temperatures. Preliminary results show that the ductile-to-brittle transition temperature is about 800 °C for this composite, and its strength is significantly higher than conventional V solid-solution alloys.

Morphology and permeability of bio-based poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene succinate) (PBS) and linear low-density polyethylene (LLDPE) blend films control shelf-life of packaged bread

Poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene succinate) (PBS) and linear low-density polyethylene (LLDPE) were blended to produce bio-based packaging via blown-film extrusion. Blend ratios modified morphology, crystallinity and relaxation temperatures (T α ) of the films. Binary mixtures caused phase separation and non-homogeneous fibrous microstructures of immiscible polymers. Bio-based blend films containing LLDPE (LLDPE/PBAT and LLDPE/PBS) gave less homogeneous structures than PBAT/PBS films. The formation of oriented fibrous networks subsequently controlled mechanical and barrier properties of the blend films. LLDPE blending modified C=O carbonyl groups in PBAT and PBS, forming voids in topographic images indicating incompatibility. PBAT and PBS blends showed good compatibility and adhesion of polymer interface, causing smooth and compact structures with minimal surface roughness. Incorporation of PBAT and PBS sharply reduced crystallinity of LLDPE/PBAT and LLDPE/PBS films. LLDPE/PBAT blends had lower T α than neat PBAT and LLDPE, while T α of PBAT/PBS blends proportionally decreased at increasing PBS which indicated diverse polymer miscibility and molecular mobility. Water vapor permeability (WVP) and oxygen permeability (OP) fitted with polynomial and exponential equations, respectively and depended on blend ratios. Films containing higher PBS had combined higher WVP and lower OP, delaying fungal growth in packaged bread due to dehydration. Ratios of PBAT, PBS and LLDPE blend films clearly affected mold growth and crumb hardness during storage. Regardless of film components, the firmness of bread crumbs increased linearly with package WVP. Conversely, mold growth had insignificant correlation with OP. Moisture loss from bread crumbs due to high WVP showed dominant effects on microbial growth. Blending PBAT and PBS modified the morphology and permeability of bio-based films and increased the shelf-life of packaged bread. • Systematic investigations for packaging properties in bio-based PBAT/PBS/PE blends. • FTIR intensity ratios effectively monitor bonding and morphology modifications. • H 2 O and O 2 permeability in PBAT/PBS/PE blends fitted to cubic and exponential model. • Hardness of packaged bread linearly increased with water vapor permeability. • Water vapor permeability majorly affected mold growth and increasing crumb hardness.