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...

The first fire on Earth ignited 420 million years ago. Today, our planet remains the only one that we know of where oxygen, fuels, and ignition sources - including humans - come together to spark flames. As fire historian Stephen Pyne writes, “We are uniquely fire creatures on a unique fire planet.”

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...

Downed timber is valuable for manufacturing biochar in environmental remediation applications due to the low cost of raw materials and low-temperature manufacturing process. Loblolly pine (Pinus taeda L.) trees at different maturities (15-, 30-, and 39-year-old) with 0, 6, and 12 months of local environmental exposure in the southeastern region of the US were collected for biochar manufacturing. The biochar samples were characterized for their physicochemical properties, including morphologies, elemental compositions, surface functional groups, carbon structure, pH, electrical conductivity,...

Land-use and land-cover (LULC) change is a primary driver of terrestrial carbon release, often through the conversion of forest into agriculture or expansion of urban areas. Classification schemes are a key component of landscape analyses. This study creates a novel LULC classification scheme by incorporating ecological data to redefine classes of an existing LULC classification based on variation in above-ground tree carbon. A tree inventory was conducted for 531 plots within a subbasin of the Tampa Bay Watershed, Florida, USA. Above-ground tree carbon was estimated using the i-Tree...

This resource update contains the findings of a canvass of all primary wood-using plants. It complements the Forest Inventory and Analysis (FIA) annual inventory of volume and removals. The canvass was conducted to determine the amount and source of wood receipts and annual timber product imports/exports. Only primary wood-using mills were canvassed. Primary mills are those that process roundwood in log or bolt form or as chipped roundwood. Examples of industrial roundwood products are saw logs, pulpwood, veneer logs, poles, and logs used for composite board products. Mills producing...