Joel Pawlak

Joel Pawlak
North Carolina State University | NCSU · Department of Forest Biomaterials

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105
Publications
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Publications

Publications (105)
Article
Full-text available
Washing synthetic textile fibers releases micro/nano plastics, endangering the environment. As new filters and associated regulations are developed to prevent fiber release from washing machines, there emerges a need to manage the collected waste, for which the only current options are combustion or landfill. Herein we show for the first time the a...
Article
Full-text available
Poly(β-hydroxybutyrate) (PHB) is a well-known biodegradable bio-based polymer but can be brittle. Polymer blending of PHB with polyethylene (PE) or polypropylene (PP) has been proposed to improve the mechanical properties. Compatibilizers have been considered to improve the performance of the polymer blend with PHB; however, the effect of compatibi...
Article
Full-text available
Paper dusting, which occurs when a tissue web releases unbound and loosely bound fibers or filler particles during tissue-making or product manufacturing, has an overall negative impact, causing safety hazards, machine runnability difficulties, and product quality issues. To date, there are no well-established industry standards to quantify dusting...
Article
Full-text available
Micro/nano plastics have sparked greater attention in recent years due to their widespread presence. Currently, several waste valorisation approaches are under development, in order to upcycle micro/nano plastics. Thermal conversion technologies such as pyrolysis, gasification, liquefaction, or hydrothermal carbonization can yield high-valuable sol...
Article
Full-text available
Nonwoven products are widely used in disposable products, such as wipes, diapers, and masks. Microfibers shed from these products in the aquatic and air environment have not been fully described. In the present study, 15 commercial single-use nonwoven products (wipes) and 16 meltblown nonwoven materials produced in a pilot plant were investigated r...
Article
Full-text available
Paper dusting has recently been recognized as a significant issue in the hygiene tissue industry. This review considers the factors that may contribute to dusting and linting, as well as the challenges of evaluating dusting propensity. Examining both the paper and textile industries, several methods of dusting and linting assessment exist. This rev...
Article
Full-text available
The hygiene tissue industry has an extensive global market that is quickly growing. Market research has indicated that softness is one of consumers’ most highly desired properties. For certain hygiene tissue products (specifically bath tissue), this property can influence prices. A better understanding of the science of softness would allow compani...
Preprint
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Global sustainability megatrends are promoting the utilization of sustainably perceived fibers such as recycled and agricultural residue fibers in hygiene tissue applications. Tissue paper products advertised as sustainable have higher prices and inferior performance than conventional products manufactured from virgin wood fibers. This work demonst...
Preprint
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Linting and dusting are commonly used terms to describe the tendency of a tissue web to release unbound and loosely bound fibers or filler particles during the tissue-making process or in the finished tissue product. Lint/dust generation has an overall negative impact across tissue paper manufacturing and handling operations, causing safety hazards...
Article
Full-text available
Arsenic and other heavy metal contaminants in water are a significant global health threat. In this study, low-cost, sulfur-free, sustainable, water-insoluble materials with heavy metal remediation properties were produced from renewable resources such as starch, xylan, citric acid, and chitosan. Synthesized starch citrate-chitosan (SCC) foam and x...
Article
The presence and biodegradability of textile microfibers shed during laundering or use is an important environmental issue. In this research, the influence of common textile finishes on the persistence of cotton fibers in an aerobic aquatic environment was assessed. The biodegradation of cotton knitted fabrics with different finishes, silicone soft...
Article
Full-text available
The importance of renewable and environmentally friendly wood pulp fibers as an input material for single-use products has grown significantly. However, discarded single-use materials are found in the environment as litter and are sometimes disposed of in wastewater. It is important that these materials are biodegradable and environmentally benign....
Article
Paenibacillus glucanolyticus SLM1 is a bacterial species isolated from black liquor that can metabolize lignocellulosic components. To improve P. glucanolyticus SLM1 growth and metabolism of lignocellulose components contained in black liquor, a Plackett-Burman and Central Composite Design (CCD) with Response Surface Methodology (RSM) approach was...
Article
The influence of common textile finishes on cotton fabrics on the generation of microfibers during laundering was assessed. Microfiber release was determined to be in the range of 9000–14,000 particles per gram of cotton fabric. Cotton knitted fabrics treated with softener and durable press generate more microfibers (1.30–1.63 mg/g fabric) during l...
Article
Full-text available
The biodegradability of polymers depends on several factors. However, the most critical aspects are the accessibility of the structure for moisture and enzyme diffusion and the capacity of the microbes in the environment to assimilate the final monomers. The accessibility of the polymer structure to enzymes and water depends primarily on crystallin...
Article
Full-text available
Hemicelluloses, the second most abundant class of biopolymers, have emerged as an immense renewable resource of biopolymers that are recognized as currently being underutilized. Carboxymethyl carbohydrates are valuable products for thickeners, viscosity control, food additive and others. Hemicellulose isolated from poplar was converted to carboxyme...
Article
The aerobic biodegradation of common textiles that shed microfibers during laundering was evaluated under the action of microbes found in the environment, such as lake and seawater, and activated sludge at a low concentration from a wastewater treatment plant (WWTP). Under these conditions, the biodegradation potential was the same in all the exper...
Article
Hemicellulose is a polymer found abundantly in lignocellulosic feedstocks, with many potential market applications. However, there has yet to be a large-scale commercial process to isolate hemicellulose from lignocellulosic biomass. A techno-economic assessment for hemicellulose extraction from sugarcane bagasse, switchgrass, and poplar was made. T...
Article
Hemicellulose is a polymer found abundantly in lignocellulosic feedstocks, with many potential market applications. However, there has yet to be a large-scale commercial process to isolate hemicellulose from lignocellulosic biomass. A techno-economic assessment for hemicellulose extraction from sugarcane bagasse, switchgrass, and poplar was made. T...
Article
Cellulose transparent and flexible film was prepared by dissolving micro-crystalline cellulose powder in Dimethylacetamide/Lithium Chloride (DMAc/LiCl) followed by regeneration in acetone and subsequent washing with water. The solution was cast on a glass plate. The interactions of water molecules and the swollen cellulose in the gel were examined...
Article
A rapid and green preparation of lignin nanoparticles was demonstrated starting from bio-refinery lignin containing grafted carbohydrates. The particles were prepared by recovering a fraction of the lignin, which contained 24% carbohydrate (by weight) as the insoluble fraction in 0.5 M NaOH. The carbohydrate content of this fraction was verified wi...
Article
Full-text available
The effect of fiber type (cotton, polyester, and rayon), temperature, and use of detergent on the number of microfibers released during laundering of knitted fabrics were studied during accelerated laboratory washing (Launder-Ometer) and home laundering experiments. Polyester and cellulose-based fabrics all shed significant amounts of microfibers a...
Article
Full-text available
The extractability of hemicellulose from different lignocellulosics depends on the source of biomass. Differences in hemicellulose extractability are believed to be due to plant-specific hemicellulose arrangement alongside lignin within the cell wall. In this research, six biomasses were used to probe hemicellulose alkaline extractability as a func...
Article
Full-text available
Softness, as a subjective perception, is difficult to define and quantify. For decades, panel tests have been used to judge differences in the softness of hygiene tissue samples. Panel tests can be a time-consuming and expensive process. A number of protocols have been developed to quantify the physical properties of tissues associated with softnes...
Article
Full-text available
This study aimed to identify the performance properties that drive the shelf price of kitchen paper towels and evaluate whether sustainability is an important driver for pricing. Nineteen products were compared according to their performance (softness, absorbency, and strength), technology, and fiber morphology. Metrics to rank the products in diff...
Chapter
The melt stability of LDPE containing 50% w/w starch/glycerol filler during multi-pass extrusion was determined by measurements of the melt-flow rate (MFR). The robustness of a polymer processing degradation index (PDI) calculation previously proposed by others in the literature is questioned and corrected before applying it to the polymer formulat...
Article
Full-text available
This study aimed to identify the performance properties that drive the shelf price of kitchen paper towels and evaluate whether sustainability is an important driver for pricing. Nineteen products were compared according to their performance (softness, absorbency, and strength), technology, and fiber morphology. Metrics to rank the products in diff...
Article
The microstructure and reactivity of a novel nonwoven cellulose fiber cellular biocomposite (microbial paper) was studied relative to long-term stabilization of potentially any microorganism. Cells were incorporated during the papermaking process as an integral component of a highly porous cellular biocomposite that can be dry stabilized. Hydrogen...
Article
Full-text available
A Clostridium ljungdahlii lab-isolated spontaneous-mutant strain, OTA1, has been shown to produce twice as much ethanol as the C. ljungdahlii ATCC 55383 strain when cultured in a mixotrophic medium containing fructose and syngas. Whole-genome sequencing identified four unique single nucleotide polymorphisms (SNPs) in the C. ljungdahlii OTA1 genome....
Article
There is significant interest in biodegradable and transparent UV protection films from renewable resourcesfor many different applications. Herein, the preparation and characterization of transparent flexible cellulose films containing low amounts of bond lignin with UV blocking properties are described. Azide modified cellulose dissolved in dimeth...
Article
Full-text available
Background: Autotrophic Clostridia are of considerable interest for use in renewable biofuel and biocommodities production. One such autotrophic Clostridium, Clostridium ljungdahlii, was the first to be identified as an ethanologenic acetogen and has been extensively studied as a microbial catalyst for the conversion of biomass derived synthesis ga...
Article
Full-text available
Clostridium ljungdahlii is an important synthesis gas fermenting bacterium used in the biofuels industry, and a preliminary investigation showed that it has some tolerance to oxygen when cultured in rich mixotrophic medium. Batch cultures not only continue to grow and consume H2, CO, and fructose after 8% O2 exposure, but fermentation product analy...
Data
The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chem...
Patent
Full-text available
Compositions of matter are provided that include chitosan and a modified carbohydrate. The modified carbohydrate includes a carbohydrate component and a cross linking agent. The modified carbohydrate has increased carboxyl content as compared to an unmodified counterpart carbohydrate. A carboxyl group of the modified carbohydrate is covalently bond...
Article
Full-text available
Lignocellulose is a term for plant materials that are composed of matrices of cellulose, hemicellulose, and lignin. Lignocellulose is a renewable feedstock for many industries. Lignocellulosic materials are used for the production of paper, fuels, and chemicals. Typically, industry focuses on transforming the polysaccharides present in lignocellulo...
Article
Acid-catalyzed vapor phase esterification with maleic anhydride was used to improve the integrity and thermo-mechanical properties of fiber webs based on poly(vinyl alcohol), PVA. The fibers were produced by electrospinning PVA from aqueous dispersions containing cellulose nanocrystals (CNCs). The effect of esterification and CNC loading on the str...
Article
Microfibrillated cellulose (MFC) created via the micro-grinding method was heterogeneously acetylated to different substitution levels using acetic anhydride and heat rather than strong acid catalysis. The acetylated MFC was formed into thin films and characterized by infrared spectroscopy and mechanical testing. Spectral and chemical analysis conf...
Article
Full-text available
The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chem...
Article
Full-text available
Cellulose and some cellulose derivatives can play vital roles in the enhancement of the performance of absorbent products. Cellulose itself, in the form of cellulosic fibers or nano-fibers, can provide structure, bulk, water-holding capacity, and channeling of fluids over a wide dimensional range. Likewise, cellulose derivatives such as carboxymeth...
Article
Hemicellulose material is an abundant and relatively under-utilized polymeric material present in lignocellulosic materials. In this research, an alkaline treatment was applied to pinewood (PW), switchgrass (SG), and coastal bermuda grass (CBG) in order to extract hemicelluloses to subsequently produce a novel biosorbent. Alkaline extraction at 75...
Article
Hemicellulose material is an abundant and relatively under-utilized hetero-polysaccharides material present in lignocellulosic materials. In this research, an alkaline treatment was applied to switchgrass in order to extract hemicelluloses to subsequently produce an acetylated product. An extraction at 75 °C recovered 27% of the biomass as a predom...
Article
Cellulose aggregate fibrils (CAFs) with dimensions of 100,000×3000×300 nm from unbleached kraft pulp (KP), oxygen delignified KP (KPox.del), and fully bleached kraft pulp (BKP) were liberated by a series of high shear and fractionation operations. The CAFs served as microfibril model material to evaluate their dimensional and hygroexpansive behavio...
Conference Paper
Full-text available
Hemicellulose material is an abundant, relatively under-utilized polymeric material present in lignocellulosic materials. In this research, an alkaline treatment was applied to wood and grasses in order to extract hemicelluloses to subsequently produce novel materials. An extraction at 75°C recovered 23% of the biomass as a predominantly hemicellul...
Article
Full-text available
Reactive extrusion is an attractive green route for cost-effective polymer processing, which has the potential to enhance the commercial viability of biomass-derived materials. In reactive extrusion, compatibilizers can be generated in the blend preparation through polymer-polymer grafting reactions using functionalized polymers. One very interesti...
Article
A series of experiments were conducted on recycled pulp samples for the novel purpose of determining the efficacy of employing soy protein flour to increase the strength of dry paper. Values of short span compression and tensile strength were the prime criteria for comparison based on industrial considerations. Various conditions were considered to...
Article
Full-text available
Microfibrillated celluloses, liberated from macroscopic lignocellulosic fibers by mechanical means, are sub-fiber elements with lengths in the micron scale and diameters ranging from 10 to a few hundred nanometers. These materials have shown strong water interactions. This article describes an investigation and quantification of the 'hard-to-remove...
Article
Ultrathin films of aligned cellulose nanocrystals (CNCs) were assembled on mica supports by using electric field-assisted shear. The relationship between polarization gradients and strain mechanics of the obtained films was examined by monitoring their deflection with an atomic force microscope operated in contact mode. The piezoelectric response o...
Article
Full-text available
Microfibrillated celluloses (MFCs) have mechanical properties sufficient for packaging applications but lack water vapor barrier properties in comparison to petroleum-based plastics. These properties can be modified by the use of mineral fillers, added within the film structure, or waxes, as surface coatings. In this investigation it was determined...
Article
Full-text available
The objective of this research was to investigate green, renewable reaction systems for xylan that introduce crosslinking and carbonyl group for improved performance in water absorption applications. Xylan was modified separately with three different reaction agents, citric acid, succinic anhydride and sodium monochloracetate (SMCA). The xylan was...
Article
Full-text available
Microfibrillated celluloses (MFCs) with diameters predominantly in the range of 10–100nm liberated from larger plant-based fibers have garnered much attention for the use in composites, coatings, and films due to large specific surface areas, renewability, and unique mechanical properties. Energy consumption during production is an important aspect...
Patent
Abstract Compositions of matter are provided that include chitosan and a modified carbohydrate. The modified carbohydrate includes a carbohydrate component and a cross linking agent. The modified carbohydrate has increased carboxyl content as compared to an unmodified counterpart carbohydrate. A carboxyl group of the modified carbohydrate is covale...
Patent
Full-text available
Compositions of matter are provided that include chitosan and a modified carbohydrate. The modified carbohydrate includes a carbohydrate component and a cross linking agent. The modified carbohydrate has increased carboxyl content as compared to an unmodified counterpart carbohydrate. A carboxyl group of the modified carbohydrate is covalently bond...
Article
Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was employed to study the sorption behaviors of cellulases on microcrystalline celluloses and hardwood pulp. The adsorption and recovery of cellulases from Aspergillus niger and Trichoderma reesei were investigated at 25 °C. Cellulase recovery was conducted by rinsing adsorbed enz...
Article
The effect of humidity on the morphological and thermomechanical properties of electrospun poly(vinyl alcohol) (PVA) fiber mats reinforced with cellulose nanocrystals (CNs) was investigated. Scanning electron microscopy (SEM) images revealed that the incorporation of CNs improved the morphological stability of the composite fibers even in high humi...
Article
Full-text available
The interactions with water and the physical properties of microfibrillated celluloses (MFCs) and associated films generated from wood pulps of different yields (containing extractives, lignin, and hemicelluloses) have been investigated. MFCs were produced by combining mechanical refining and a high pressure treatment using a homogenizer. The produ...
Article
The objective of this research was to synthesize and characterize high-value foam gel materials with unique absorptive and mechanical properties from starch citrate-chitosan. The effects of starch citrate concentration, pH, solid to liquid ratio, reaction time, and temperature on absorbency, weight loss in water, and strength were determined. The c...
Article
Atomic force microscopy (AFM) studies of the dimensional changes of cellulose microfibril materials, called cellulose aggregate fibrils (approx. 100µm×3µm×300nm), exposed to two distinct relative humidities of 80% and 23% for 24h and then suddenly subjected to 50% RH and 23°C show that the fibrils are responsive to the surrounding environments in a...
Conference Paper
Full-text available
A process has been developed for dissolving cellulose or a polysaccharide and cellulose to make polymer membranes, using ethylenediamine based mixed solvent / salt system. The membranes were cast, coagulated and then processed to remove the mixed solvent / salt. These membranes were then dried in ambient conditions and then at 50 oC in a vacuum ove...
Article
Cellulose nanocrystals (CN) were used to reinforce nanofibers in composite mats produced via electrospinning of poly(vinyl alcohol) (PVA) with two different concentrations of acetyl groups. Ultrathin cross-sections of the obtained nanocomposites consisted of fibers with maximum diameters of about 290 nm for all the CN loads investigated (from 0 to...
Article
Films of microfibrillated celluloses (MFCs) from pulps of different yields, containing varying amounts of extractives, lignin, and hemicelluloses, were produced by combining refining and high-pressure homogenization techniques. MFC films were produced using a casting-evaporation technique and the physical and mechanical properties (including densit...
Article
Full-text available
Starch microcellular foams (SMCF) containing pores in the micron size range may be prepared by pore-preserving drying processes, developing highly porous, high specific surface area materials useful for applications such as opacifying pigments or as adsorbent materials. The objective of this research was to understand how the exchange of water with...
Conference Paper
Hemicellulose citrate-chitosan foams were formed by first modifying hemicellulose with citric acid to create a hemicellulose citrate that was subsequently linked to chitosan. The resulting material was freeze dried to form a foam structure. The foams were tested for strength, water, and saline solution absorption as well as their ability to complex...
Article
Starch microcellular foams (SMCF) containing pores in the micron size range may be prepared by pore-preserving drying processes, developing highly porous, high specific surface area materials useful for applications such as opacifying pigments or as adsorbent materials. The objective of this research was to understand how the exchange of water with...
Conference Paper
There is an interest to produce hydrophobic biodegradable materials from renewable resources like starch that can be utilized as a filler or pigment in paper, coating, and packaging applications. Starch microcellular foams (SMCF) are foams prepared by pore preserving drying (solvent exchange) or formation processes that contain significant concentr...
Article
Starch microcellular foams (SMCFs) are prepared by pore preserving drying or formation processes and contain pores in the micron size range. SMCFs have high specific surface area and are useful for applications such as opacifying pigments or as adsorbent materials. The objective of this research was to determine how the processing conditions and us...
Article
Full-text available
The production of microporous carbon foams from renewable starch microcellular foam-fiber (SMCF-Fiber) composites is described. Carbon foams are used in applications such as thermal insulation, battery electrodes, filters, fuel cells, and medical devices. SMCF-Fiber compos-ites were created from an aquagel. The water in the aquagel was exchanged wi...
Article
The production of a hydrophobic starch microcellular foam (SMCF) through the addition of an alkyl ketene dimer (AKD) would be a bio-based material with valuable properties for many applications in which high specific surface area, low density and water resistance is important. Pigments for paper and coatings are a potential application. An emulsion...
Article
Full-text available
This review article highlights progress in understanding the optical properties of paper. Paper's appearance can be defined in terms of its opacity, brightness, color, fluorescent properties, gloss, and various quantities related to its uniformity. The phenomena that give rise to paper's optical properties, especially its ability to scatter and abs...
Conference Paper
Full-text available
There is an interest to produce hydrophobic biodegradable materials from renewable resources like starch that can be utilized as a filler or pigment in paper, coating, and packaging applications. Over the last two decades significant research has been conducted to utilize starch in its solid form as a biodegradable material. Starch microcellular fo...