Thin Cellulose Research Articles

Characterization of Structure and Morphology of Cellulose Lyocell Microfibers Extracted from PAN Matrix

Polymer matrices can be reinforced with cellulose fillers in a variety of geometric shapes. Depending on the morphology of the particles, the volume fraction of the composite additive may decrease, while the values of the elastic modulus may increase. Increasing the length while decreasing the width of the cellulose filler is an intriguing path in the development of composite additives and materials based on it. It is difficult to form thin continuous cellulose fibers, but this can be accomplished via the sea-island composite fiber manufacturing process. The creation of cellulose fibrils in polyacrylonitrile (PAN)/cellulose based systems happens during the spinning of the mixed solution. A selective solvent facilitates the isolation of cellulose fibrils. The structure of the isolated microfibers was investigated using X-ray diffraction, IR spectroscopy, SEM, and AFM. The structure of the resulting cellulose microfibers was compared to bacterial cellulose. It has been shown that composite fibers have a superposition pattern, while cellulose fibrils have a structure different from native cellulose and similar to Lyocell fibers (polymorph II). The crystallite sizes and crystallinity of regenerated cellulose were determined. The identified structural parameters for cellulose fibrils provide strength at the level of industrial hydrated cellulose fibers.

Microporous Polyethylene and Cellulose Composite Separators for Reversible Lithium Electrode in Lithium Rechargeable Batteries

AbstractThe lithium metal anode is the best candidate for high energy density batteries because of its high specific capacity and low negative potential. Rechargeable lithium metal batteries (RLMB) have not yet been commercialized. The key factors that limit the practical use of RLMB are the formation and growth of lithium dendrites during the lithium deposition process and the reaction of the lithium anode with the organic solvent of the electrolyte, quantified by the Columbic efficiency (CE). To suppress the lithium dendrite formation and to improve CE, many approaches such as the formation of a protective layer on the lithium electrode and the use of additives to the electrolyte have been proposed. In this study, the effect of a thin cellulose film to improve CE of lithium deposition and stripping on the lithium electrode was examined. The cycle performance of a Li/Li symmetrical cell with a cellulose and polyethylene composite separator was examined for a carbonate electrolyte and an ether electrolyte. The improvements of CE were observed for both electrolytes with the cellulose film separator. The improvement could be explained by the good wettability of the cellulose film separator with the electrolyte.

Unveiling the Multifunctional Carbon Fiber Structural Battery.

Structural batteries refer to the multifunctional device capable of both storing electrical energy and bearing mechanical loads concurrently. In this context, carbon fibers emerge as a compelling choice of material and serve dual purpose by storing energy and providing stiffness and strength to the battery. Previous investigation has demonstrated proof-of-concept of functional positive electrodes against metallic lithium in structural battery electrolyte. Here, an all-carbon fiber-based structural battery is demonstrated utilizing the pristine carbon fiber as negative electrode, lithium iron phosphate (LFP)-coated carbon fiber as positive electrode, and a thin cellulose separator. All components are embedded in structural battery electrolyte and cured to provide rigidity to the battery. The energy density of structural battery is enhanced by use of the thin separator. The structural battery composite demonstrates an energy density of 30Whkg-1 and cyclic stability up to 1000 cycles with ≈100% of Coulombic efficiency. Remarkably, the elastic modulus of the all-fiber structural battery exceeds 76GPa when tested in parallel to the fiber direction - by far highest till date reported in the literature. Structural batteries have immediate implication in replacing structural parts of electric vehicles while reducing the number of conventional batteries. Thus, offering mass savings to future electric vehicles.

An environmentally friendly and scalable manufacturing route to the high performance composite polymer electrolytes for lithium-metal batteries

Environmentally friendly manufacturing of flexible all-solid-state electrolytes in large-scale and low cost is important for market entering of lithium metal batteries. Herein, a simple and practical solvent-free route to the high performance composite polymer electrolyte is proposed by infiltrating the hot-molten polyether polymer (F127)/Li-salt (LiTFSI) slurry into a thin cellulose fibrous membrane. The good compatibility between the slurry and cellulose membrane allows the formation of a highly dense F127/LiTFSI/cellulose composite electrolyte with a thin thickness of 28 μm. The solvent-free feature without side-reaction as well as the good mechanical stability of such electrolyte makes great significance to ensure the safety and stability of the batteries. Therefore, its Li symmetric cell can stably operate with an ultralong lifespan of more than 3600 h without dendritic growth of metal lithium, and the LiFePO4//Li cell can also deliver an excellent cycling stability with an initial capacity of 130.1 mAh g−1 and a capacity retention of 84.11 % after more than 260 cycles at 0.5C and 60 °C. Additionally, the performance of high-loading cathode full cell and the flexible pouch cell further confirm its excellent stability and safety for practical use.

Electrospun Core-Sheath Nanofibers with a Cellulose Acetate Coating for the Synergistic Release of Zinc Ion and Drugs.

Precisely modulating the synergistic release behavior of multiple bioactive substances has emerged as a formidable challenge in recent years. In this work, we successfully prepared core-sheath nanofibers, where a thin cellulose acetate (CA) coating enrobed the core. Curcumin (Cur) was encapsulated in the core layer as a model drug, while zinc oxide (ZnO) nanoparticles were loaded on the sheath layer. The prepared fiber exhibited a straight cylindrical morphology containing nanoparticles, and the distinct core-sheath nanostructure was demonstrated through transmission electron microscopy (TEM). X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were conducted to study the physical state and compatibility among CA, Cur, and ZnO. Drug release data indicated that core-sheath nanofibers were able to decelerate the rate of drug release, and the thickness of the sheath layer increased in the presence of ZnO particles. Most remarkably, these core-sheath nanofibers exhibited the remarkable ability to sustain the release of drugs and zinc ion (Zn2+), the two-day synergistically release behavior leading to a significant increase in cell proliferation. This material preparation strategy for the synergistic and controlled release of two bioactive substances is instructive for the exploration of innovative and versatile drug delivery systems.

Nanoscopic lignin mapping on cellulose nanofibers via scanning transmission electron microscopy and atomic force microscopy

Cellulose has been developed as an alternative to petrochemical materials. By comparison with refined nanofibers (RCNFs), lignocellulose nanofibers (LCNFs) show particular promise because it is produced from biomass using only mild pretreatment. The mechanical properties of LCNFs depend on the contained lignin. However, the microscopic location of the lignin contained in LCNFs has not been determined. Thus, we developed two methods to detect and visualize lignin. One uses a scanning transmission electron microscope (STEM) equipped with an energy dispersive X-ray spectroscopy detector. The other method uses an atomic force microscope (AFM) equipped with a cantilever coated with an aromatic molecule. Both methods revealed that the lignin in LCNFs covers a thin cellulose fiber and is precipitated in a grained structure. In particular, the AFM system was able to determine the nanoscopic location of lignin-rich areas. The present study establishes a strong tool for analyzing the characteristics of lignin-containing materials.Graphical abstract

On the strain stiffening and nanofiber orientation of physically crosslinked nanocellulose hydrogels

Nanocellulose hydrogels that consist of physically crosslinked nanofibrous networks with large amounts of interstitial water have many potential applications as structural materials in biomedical engineering. Quantifying the relationship between micro/nanostructures and their mechanical responses can provide some guidelines for the high-performance mechanical design of counterparts. To this end, we develop a modified physically based constitutive model for examining the effects of the micro/nanostructures of a nanofibrous network on the strain stiffening behaviors of nanocellulose hydrogels under stretching. In addition to the configurational entropy of cellulose nanofiber and mixing energy of water molecule, this theoretical model is particularly concerned with the contribution of the potential energy of hydrogen bond in a thermodynamics framework. Increasing the physical crosslinks between cellulose nanofibers or decreasing the content of water molecules in a certain range can enhance the strain stiffening behaviors of nanocellulose hydrogels. Relatively long and thin cellulose nanofibers have increased tensile strengths. The theoretical predictions are in good agreement with the relevant experimental results. We propose a fiber orientation model for quantifying the relationship between the nanofiber orientation degree and mechanical stretching. This model provides a theoretical foundation for fabricating anisotropic nanofibrous hydrogels via cold drawing.

APPLICATION OF CHITOSAN-BASED PRODUCTS TO INCREASE HYDROPHOBIC PROPERTIES OF CRAFT PA-PER

We devoted our research to study and substantiate the possibility of using products based on commercial chitosan. As an animal polysaccharide, it was applied as an additive in manufacturing laboratory samples of kraft packaging paper with increased hydrophobic properties.
 The research aimed to optimize conditions to produce packaging kraft paper by means of mathematical planning method of the experiment in accordance with the three factor uniform-rotatable second-order model by Box and Hunter.
 It is shown that that the effective hydrophobization of a fairly thin cellulose fibrous material, weight of 1 m2 70 g, is possible. In the studied factor space, we have established mathematical dependences that fit well the influence of the main technological parameters – the consumption of chitosan (0.5–1.5%), the beating degree of paper pulp (25–35 °SR) and softwood content in fiber furnish (80–100%) on the hydrophobicity (increasing moisture resistance) of paper and its physical and mechanical properties.
 It is shown that the presence of chitosan in fiber furnish leads to the hydrophobicity of kraft paper in terms of surface water absorption during one-sided wetting (Cobb test) increases many times and reaches 24–25 g/m2 at the maximum product consumption (1.5%). At the same time, the values of beating degree of paper pulp and softwood content in fiber furnish can vary in a fairly wide technological range, in accordance with the studied factor spaces.
 Increasing the consumption of chitosan, the beating degree of pulp fibers and softwood content in fiber furnish simultaneously provides an increase in the values of almost all physical and mechanical properties of laboratory kraft packaging paper.

Quartz crystal microbalance with dissipation (QCM-D) as a way to study adsorption and adsorbed layer characteristics of hemicelluloses and other macromolecules on thin cellulose films: A Review

Cellulose and hemicellulose are abundant renewable resources. Thus, studying the adsorption mechanism of hemicellulose adsorption onto cellulose will contribute to further understanding of the fiber network, promote the development of new materials, and improve the utilization rate of resources. Quartz crystal microbalance with dissipative (QCM-D) is a research tool that can monitor quality changes at nanograms level; it is often used in the field of adsorption. Starting from the interaction between cellulose and hemicellulose, this paper outlines research on the principle, influencing factors, and kinetics of hemicellulose adsorption onto cellulose by QCM-D and expounds the research methods and means in the field of adsorption of similar biomass that can be used for reference. It provides a reference for further study of adsorption mechanism.

UV-cured Polymer Solid Electrolyte Reinforced using a Ceramic-Polymer Composite Layer for Stable Solid-State Li Metal Batteries

In recent years, solid-state Li metal batteries (SSLBs) have attracted significant attention as the next-generation batteries with high energy and power densities. However, uncontrolled dendrite growth and the resulting pulverization of Li during repeated plating/stripping processes must be addressed for practical applications. Herein, we report a plastic-crystal-based polymer/ceramic composite solid electrolyte (PCCE) to resolve these issues. To fabricate the one-side ceramic-incorporated PCCE (CI-PCCE) film, a mixed precursor solution comprising plastic-crystal-based polymer (succinonitrile, SN) with garnet-structured ceramic (Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub>, LLZO) particles was infused into a thin cellulose membrane, which was used as a mechanical framework, and subsequently solidified by using UV-irradiation. The CI-PCCE exhibited good flexibility and a high room-temperature ionic conductivity of over 10<sup>−3</sup> S cm<sup>−1</sup>. The Li symmetric cell assembled with CI-PCCE provided enhanced durability against Li dendrite penetration through the solid electrolyte (SE) layer than those with LLZO-free PCCEs and exhibited long-term cycling stability (over 200 h) for Li plating/stripping. The enhanced Li<sup>+</sup> transference number and lower interfacial resistance of CI-PCCE indicate that the ceramic-polymer composite layer in contact with the Li anode enabled the uniform distribution of Li<sup>+</sup> flux at the interface between the Li metal and CI-PCCE, thereby promoting uniform Li plating/stripping. Consequently, the Li//LiFePO<sub>4</sub> (LFP) full cell constructed with CI-PCCE demonstrated superior rate capability (~120 mAh g<sup>−1</sup> at 2 C) and stable cycle performance (80% after 100 cycles) than those with ceramic-free PCCE.

A three-dimensional human adipocyte model of fatty acid-induced obesity

Obesity prevalence has reached pandemic proportions, leaving individuals at high risk for the development of diseases such as cancer and type 2 diabetes. In obesity, to accommodate excess lipid storage, adipocytes become hypertrophic, which is associated with an increased pro-inflammatory cytokine secretion and dysfunction of metabolic processes such as insulin signaling and lipolysis. Targeting adipocyte dysfunction is an important strategy to prevent the development of obesity-associated disease. However, it is unclear how accurately animal models reflect human biology, and the long-term culture of human hypertrophic adipocytes in an in vitro 2D monolayer is challenging due to the buoyant nature of adipocytes. Here we describe the development of a human 3D in vitro disease model that recapitulates hallmarks of obese adipocyte dysfunction. First, primary human adipose-derived mesenchymal stromal cells are embedded in hydrogel, and infiltrated into a thin cellulose scaffold. The thin microtissue profile allows for efficient assembly and image-based analysis. After adipocyte differentiation, the scaffold is stimulated with oleic or palmitic acid to mimic caloric overload. Using functional assays, we demonstrated that this treatment induced important obese adipocyte characteristics such as a larger lipid droplet size, increased basal lipolysis, insulin resistance and a change in macrophage gene expression through adipocyte-conditioned media. This 3D disease model mimics physiologically relevant hallmarks of obese adipocytes, to enable investigations into the mechanisms by which dysfunctional adipocytes contribute to disease.

Processing and rheological properties of polyol/cellulose nanofibre dispersions for polyurethanes

Polyols are widely used as precursors, compatibilisers, and viscosity modifiers in the polymer, food, and paint industries, and their rheological properties are critical for engineering the optimal performance of final products and enabling new and diverse applications. This study investigates the mechanical and viscoelastic properties of a polyether polyol filled with long thin cellulose nanofibres (CNF). It provides insights into the influence of loading levels on mechanisms of dispersion, interaction, and gelation behaviour. The steady-shear rheological measurements revealed four different regimes of flow behaviour associated with increasing viscosity and yield stress with increasing loading of CNF in the polyol. The oscillatory-shear rheology enabled a better understanding of interactions of CNF dispersed in the polyol and the determination of the threshold concentration of CNF for percolation network formation. The correlation of mechanical properties of the polyol nanocomposites with Shih et al. suggests the network formation of intraflocs of fractal dimension two at the higher loadings of CNF.

The fire hazard potential of thermally thin cellulose nonwovens with different overlap configurations

The fire hazard potential of nonwovens with different overlap configurations and various thicknesses between 0.5 and 5 mm were investigated to clarify the possible worsening situation induced by the difference in overlapping configurations. The fire hazard of thermally thin nonwovens is characterized by flame spread, flame height, temperature distribution, and mass loss. The flame spread rate and FDI (fire development index) increase and then decrease as the thickness of the nonwovens increases. The fire hazard potential of samples with OL configuration (overlapping layer by layer configuration) is higher than that with AO configuration (accordion-style overlap configuration), which is reflected in the high FDI, average fire spread rate, and flame height, and low ignition time. The difference between the fire risk of the two overlapping configurations was confirmed by analyzing the heat transfer mechanism. Due to the different packaging methods, the AO and OL configurations of nonwovens show different degrees of shrinkage and curling effects during combustion. The large air gap between the layers and the weight of the sample edge are the reasons for the weak contraction of the sample with an AO configuration. The sample shrinkage with OL configuration strengthens the flame spread to a certain extent by increasing the convective heat transfer in the preheat zone.

Three-dimensional analysis of aligner gaps and thickness distributions, using hard x-ray tomography with micrometer resolution.

The morphology of a polymer aligner, designed according to an orthodontic treatment plan, determines clinical outcomes. A fundamental element of orthodontic tooth movement with aligner treatment is the fit of the aligner's surface to the individual teeth. Gaps between the aligner and teeth do occur because current aligner fabrication is not capable of completely reproducing the complex anatomy of the individual denture. Our study aims at a quantitative three-dimensional assessment of the fit between optically transparent aligners placed on a polymeric model of the upper dental arch for two thermofoil thicknesses at preselected thermoforming temperatures. Using an intraoral scan of a subject's upper dental arch, eight models were printed using a stereolithographic system. A series of eight NaturAligners® was manufactured with a pressure molding process, using thermofoils with thicknesses of 550 and and preselected process temperatures between 110°C and 210°C. These aligners placed on the corresponding models were imaged by an advanced micro computed tomography system. The aligners and the models were segmented to extract the gaps and aligners' local thicknesses as a function of the processing temperature for the two foil thicknesses. The results indicate that the aligners show a better fit when the foils are processed at higher temperatures. Nevertheless, processing temperatures can be kept below 150°C, as the gain becomes negligible. Thermal processing reduces the average thickness of the aligners to 60% with respect to the planar starting foil. These thickness distributions demonstrate that the aligners are generally thicker on the occlusal surfaces of molars and premolars but thinner around the incisors and buccal as well as on oral surfaces. Hard x-ray tomography with micrometer resolution is a powerful technique employed to localize the gaps between aligners and teeth, and it also enables film thickness measurements after thermoforming. The thicker film on the occlusal surfaces is most welcome because of aligner abrasion during wear. The NaturAligner® surfaces consist of a -thin cellulose layer, and thus the microplastics released via abrasion of less than this thickness are expected to be substantially less critical than for other commercially available, optically transparent aligners.

Optical Detection of Acetone Using “Turn-Off” Fluorescent Rice Straw Based Cellulose Carbon Dots Imprinted onto Paper Dipstick for Diabetes Monitoring

Persistent bad breath has been reported as a sign of serious diabetes health conditions. If an individual’s breath has a strong odor of acetone, it may indicate high levels of ketones in the blood owing to diabetic ketoacidosis. Thus, acetone gas in the breath of patients with diabetes can be detected using the current easy-to-use fluorescent test dipstick. In another vein, rice straw waste is the most well-known solid pollutant worldwide. Thus, finding a simple technique to change rice straw into a valuable material is highly important. A straightforward and environmentally friendly approach for reprocessing rice straw as a starting material for the creation of fluorescent nitrogen-doped carbon dots (NCDs) has been established. The preparation process of NCDs was carried out via one-pot hydrothermal carbonization using NH4OH as a passivation substance. A testing strip was developed on the basis of cellulose CD nanoparticles (NPs) immobilized onto cellulose paper assay. The NCDs demonstrated a quantum yield of 23.76%. A fluorescence wavelength was detected at 443 nm upon applying an excitation wavelength of 354 nm. NCDs demonstrated remarkable selectivity for acetone gas as their fluorescence was definitely exposed to quenching by acetone as a consequence of the inner filter effect. A linear correlation was observed across the concentration range of 0.5–150 mM. To detect and measure acetone gas, the present cellulose paper strip has a “switch off” fluorescent signal. A readout limit was accomplished for an aqueous solution of acetone as low as 0.5 mM under ambient conditions. The chromogenic fluorescence of the cellulose assay responsiveness depends on the fluorescence quenching characteristic of the cellulose carbon dots in acetone. A thin fluorescent cellulose carbon dot layer was deposited onto the surface of cellulose strips by a simple impregnation process. CDs were made using NP morphology and analyzed using infrared spectroscopy and transmission electron microscopy. The carbon dot distribution on the paper strip was evaluated by scanning electron microscope and energy-dispersive X-ray analysis. The absorption and fluorescence spectral analyses were investigated. The paper sheets’ mechanical qualities were also examined.

Effect of colder stream temperature control on energy utilization, flux, RSF, and membrane integrity in asymmetric temperature FO systems

Water and energy are key components to assess the feasibility of any water treatment technique. For industrial applications of forward osmosis (FO), energy optimization needs to be explored further. Asymmetric temperature conditions, having different feed solution (FS) and draw solution (DS) temperatures, are likely to occur in industrial FO applications and are least explored. Some standard practices are followed without any scientific evidence of their impact on the system performance and energy utilization, like maintaining the colder stream temperature instead of letting it reach a steady state with the hotter stream. This study compares water flux, reverse solute flux (RSF), and energy utilization when the colder stream temperature is maintained and not maintained. Thin film composite-poly amide (TFC-PA) and cellulose triacetate (CTA) membranes were used at laboratory-scale in 24 h batch experiments with 0.75 M NaCl as DS and DI water as FS. All possible configurations of membrane orientation (AL-DS and AL-FS) and streams heating and cooling strategies were studied. The module material was made up of plexi-glass with 4 cm thick plates and flexible tubing of PVC was used. Results revealed that under not maintained conditions, on average, the water flux increased by 9.1–17%, RSF increased by 13.8–27.3%, and energy consumption reduced by 75.8–67% with CTA and TFC membranes, respectively. Therefore, if the RSF is not the primary concern of the application, it is advantageous not to maintain the colder stream temperature. However, it is recommended that scientists verify and compare the efficiencies between maintained and not maintained temperatures under their specific experimental conditions.

Hemicellulose content affects the properties of cellulose nanofibrils produced from softwood pulp fibres by LPMO

After lytic polysaccharide monooxygenase (LPMO) treatment, colloidally stable and thin cellulose nanofibrils (CNFs) of a uniform width are produced from kraft pulp fibres, which has a higher hemicellulose content than dissolving pulp fibres.

Pilot-scale modification of polyethersulfone membrane with a size and charge selective nanocellulose layer

The utilisation of plant-derived nanoscale cellulosic materials (cellulose nanofibrils, CNF) in tailoring water purification membranes is constantly gaining interest in the context of green-functionalised membrane solutions. However, most of the existing approaches based on renewable and biobased materials suffer from the lack of efficient and scalable processing strategies. Here, we introduce a roll-to-roll membrane modification approach based on thin submicron nanocellulose coatings (400–800 nm) to manufacture anti-biofouling membranes with size and charge dependent selectivity using unit operations compatible with existing industrial lines. We turned a commercial polymeric polyethersulfone (PES) microfiltration membrane into highly hydrophilic and tight membrane structure by applying thin and water-durable cellulose nanofibril layers using cast or spray coating methods. Nanocellulose coated membranes exhibited water permeance values of 80 – 100 LMH/MPa with the highest rejection levels of > 90% for Cytochrome C. Furthermore, the nanocellulose layers were able to withstand relatively high filtration pressure levels of 1 MPa, indicating that the selected procedures to improve mechanical integrity i.e. polyethylene imine-based anchoring and acid induced CNF cross-linking were successful. The coated membranes with the thinnest nanocellulose layer exhibited a molecular weight cut-off (MWCO) of 2 kDa for negatively charged polystyrene sulfonate and 14 kDa for neutral dextrane indicating charge selective behaviour. It can be concluded that our nanocellulose coated PES membranes represent nanofiltration membranes and lower boundary of ultrafiltration membranes with clear anti-biofouling performance directly evidenced via systematic bovine serum albumin (BSA) adsorption investigations. Our approach paves the way towards tunable and sustainable water treatment technologies simultaneously opening space for novel biobased solutions in membrane sector.

Life Cycle Assessment application for emerging membrane recycling technologies: From reverse osmosis into forward osmosis

Recycling end-of-life (EoL) reverse osmosis (RO) membrane modules into forward osmosis (FO) membranes is an innovative alternative to approach membrane science into Circular Economy (CE). Membrane modules are chemically modified and disassembled. This strategy achieves the valorisation of 69% of the membrane area and 63.7% of the plastic components. This study aims to assess the environmental potential of the above-mentioned recycling strategy. Therefore, a Life Cycle Assessment (LCA) was conducted with a substitution approach. The recycling strategy was compared with commercial Thin Film Composite (TFC) and Cellulose Triacetate (CTA) membranes at two different solution concentrations. To introduce the membrane performance comparison, a substitutability factor (SF) was developed with the flow ratio. OpenLCA 1.7.4 with Ecoinvent v3.4 and ILCD-midpoint and endpoint impact methods were used. The inventories of the commercial membranes were developed through membrane surface characterisation techniques, patents and lab protocols. One critical point during the inventory development was the estimation of solvent losses through BREF documents. However, a sensitivity analysis was performed to evaluate its relevance in decision making. Results pointed out the interest in almost all ILCD-midpoint categories and all the ILCD-endpoint categories. IR-hh, IR-e and Feu Categories were unfavourable coinciding with low environmental credits of the plastic valorisation. Sensitivity analysis identified solvent losses as a source of error.

Quantitative infrared image analysis of simultaneous upstream and downstream microgravity flame spread over thermally thin cellulose fuel in low speed forced flow

Quantitative image analysis of infrared (IR) measurements are compared to visible color images for simultaneous upstream and downstream flame spread over thermally thin cellulose samples in low speed forced flow in microgravity. These results are a unique set of data that provide a wealth of information to guide future modeling efforts. Test conditions at ambient pressure were conducted in 21–50% O2 by volume (N2 balance) and forced flow velocities from 2 cm/s to 20 cm/s. The tests conditions encompass strictly upstream flame spread to simultaneous upstream and downstream flame spread. Steady upstream flame spread is observed while the downstream flame only begins to spread at the highest flow velocities due to the oxygen shadow cast by the upstream flame (oxygen depleted region downstream of the flame). Blackbody surface temperature gradients for the upstream flame are an order of magnitude larger than the downstream gradients. Upstream preheat lengths decrease with flow while downstream preheat lengths increase. Downstream pyrolysis lengths reach steady state for most cases and increase with convective heating while upstream pyrolysis lengths increase with time. Surface thermocouple (TC) histories were non-dimensionalized to obtain a characteristic surface temperature profile using new scaling analyses. Applying the ellipticity of the leading edge to the scaling reveals the local flow velocity at the leading edge is on the order of diffusive velocities and the flame thermal expansion acts as a significant barrier to divert the flow. A surface energy balance reveals that the peak heat flux for both upstream and downstream flames increases with oxygen concentration and forced flow velocity. The upstream flame heat flux is equally divided between fuel heat up and surface radiation. The downstream heat flux goes almost exclusively to surface radiation. Comparisons of these results to previous applicable research are provided throughout the text and generally agree well.