Treesearch

Rigid lignin foam is prepared by a baking method using kraft lignin as the sole source. The eco-forming process involved cold-pressing kraft lignin powder into a solid block, heating the solid block to form lignin foam, and finally curing and cooling the lignin foam to obtain an open-cell, rigid foam. Both adsorbed water and water generated from the dehydration of hydroxyl groups in the lignin served as the blowing agent in this baking method. It was found that as the moisture content of lignin decreased, the foam densities increased, the mean bubble sizes decreased, and the bubble size...

Thermal conversion of kraft lignin, an abundant renewable aromatic substrate, into advanced carbon materials including graphitic carbon and multilayer/turbostratic graphene has recently attracted great interest. Our innovative catalytic upgrading approach integrated with molecular cracking and welding (MCW) enables mass production of lignin-derived multilayer graphene-based materials. To understand the critical role of metal catalysts in the synthesis of multilayer graphene, this study was focused on investigating the effects of transition metals (i.e., molybdenum (Mo), nickel (Ni), copper...

This study evaluated, for the first time, the feasibility of using 100% microfibrillated cellulose (MFC) for a barrier coating to preserve the shelf life of bananas. MFC was produced from a commercial bleached kraft hardwood pulp through mechanical milling. Barrier coating was accomplished by dipping bananas into aqueous MFC suspensions. Performance of the barrier coating on the banana peel surface was evaluated from visual observations, weight loss, firmness, and dissolved soluble sugars content of the bananas. The results indicated that coating the banana peel surface with MFC delayed...

This study conducted a detailed evaluation of the feasibility of producing cellulose microfibrils (CMF) from a kraft-bleached hardwood pulp at high solid contents with and without pretreatments. CMFs produced by planetary ball milling at solid contents 17 and 28% were compare with those from 1 to 5% under the same milling conditions. Fiber pretreatments using a commercial endoglucanase and mechanical refining using a laboratory PFI mill were also applied before ball milling at a solid content of 28%. Two mechanisms of fiber fibrillation were identified from the results obtained: (i) ball...

Cellulose nanomaterials have been demonstrated to be excellent barriers against grease, oxygen, and other vapors, but their implementation in packaging materials is challenging because of numerous technical and practical challenges. In this work, the oxygen, air, grease, and heptane barrier performance of copy papers coated with cellulose nanocrystals (CNCs), oxidized cellulose nanofibrils (TOCNs), and carboxymethyl cellulose (CMC) weas examined. The effects of different materials and processing conditions were evaluated for their impacts on the resulting barrier properties. TOCN coatings...

Resin canals produce and transport oleoresins that are important for tree defenses within the Pinaceae family. Rapid measurement techniques are needed to better understand how resin canal characteristics vary due to genetic and environmental effects. Here we describe a semi-automated microscopy imaging system that was built for quantifying longitudinal resin canals. Tree increment cores from 210 loblolly pine ( Pinus taeda L.) trees were prepared into radial strips and the transverse surface of the samples polished with 400 and then 600 grit sandpaper. Each sample was imaged along its...

Rapid, accurate determination of wood moisture content is paramount for the wood industry, infrastructure maintenance, studies of plant physiology, and forest management. Near-IR reflectance spectroscopy (NIRS) is a widely used nondestructive technique for analyzing the properties of materials, including MC. Small, portable, handheld NIR spectrometers represent an emerging technology with strong potential for rapidly, affordably estimating materials properties. Here, we used a SCiOTM miniature handheld NIR spectrometer and a partial least squares regression model to predict wood MC. The...

Laser-induced graphene (LIG) has emerged as a versatile carbon material for broad applications. However, the synthesis of high-quality LIG materials, especially with low defects, remains underexplored. This study was thus focused on developing a facile and cost-effective alternative to producing low-defect LIG, especially using lignin as a renewable precursor. The results showed that lignin treated by methyl ethyl ketone yielded LIG with a markedly low-defect level (ID/IG ratio of 0.12) by direct laser writing under ambient conditions. The triboelectric tactile sensor fabricated from...

The detrimental issues surrounding the accumulation of traditional plastic waste are well known. A myriad of research has been conducted in the past few decades related to the synthesis of polymers using plant oils as starting monomers to obtain polymers from renewable sources. These polymers can be biodegradable and, therefore, can decrease further plastic waste accumulation. Although many studies have been conducted on the polymerization of soybean oil (SBO), comparatively few studies have been conducted on the polymerization of cottonseed oil (CSO). CSO is an excellent candidate for a...

Exploring food packaging films from environmentally friendly materials and their practical manufacturing routes are important research topics for academia and industry. Poly (lactic acid) (PLA) is a bio-based plastic being used commercially but with low barrier performance for food packaging applications. Cellulose nanocrystals (CNCs), as renewable materials, show potential use in packaging applications, attributed to their excellent oxygen barrier performance. However, pure CNC films cannot be readily produced and used because of their brittleness and water sensitivity. Creating a...