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The stabilization kinetics of polyacrylonitrile-co-methacrylic acid (PAN-co-MAA) and cellulose nanocrystal (CNC) composite films were studied with up to 40 wt% CNC loading using differential scanning calorimetry (DSC). It was determined that the addition of CNC reduced the activation energy of the polyacrylonitrile cyclization reaction by 16% irrespective of the CNC loading in the range of 5e40 wt%. There was also a development of a new exothermic peak in the PAN-co-MAA/CNC composite films after cyclization not seen in the neat PAN-co-MAA and neat CNC samples, indicating a different set of...

This study focused on the penetration of adhesive into cell lumens and cell walls. Douglas-fir samples containing an iodinated phenol-formaldehyde adhesive were analyzed using nano-X-ray computed tomography (XCT), X-ray fluorescence microscopy, and energy-dispersive X-ray spectroscopy to observe adhesive penetration in cell walls. A gradient of penetration was observed within the cell wall structure. In addition, these nano-XCT datasets were indexed to previous micro-XCT datasets, which gave the ability to link the nanoscale cell wall penetration to microscale penetration in to the porous...

Elastomeric sealants are vital to the construction of energy efficient and water tight buildings. Sealants are a small fraction of the construction budget. Upon failure their removal and reinstallation, and repair of moisture/mold damage can run in to the 10’s of millions with the added risk of illness based litigation. In this research program we are seeking to discern the significance of environmental and strain effects on sealant durability as well as the initial state of stress (aka installation/cure conditions). Sealant bonded specimens are fixtured on automated test instruments and...

Cellulose nanocrystals (CNCs) can be attractive templates for the generation of functional inorganic/organic nanoparticles, given their fine sizes, aspect ratios, and sustainable worldwide availability in abundant quantities. Here, we present for the first time a scalable, surfactant-free, tailorable wet chemical process for converting commercially available CNCs into individual aspected gold nanoshell-bearing particles with tunable surface plasmon resonance bands. Using a rational cellulose functionalization approach, stable suspensions of positively charged CNCs have been generated....

A new family of materials comprised of cellulose, cellulose nanomaterials (CNMs), having properties and functionalities distinct from molecular cellulose and wood pulp, is being developed for applications that were once thought impossible for cellulosic materials. Commercialization, paralleled by research in this field, is fueled by the unique combination of characteristics, such as high on-axis stiffness, sustainability, scalability, and mechanical reinforcement of a wide variety of materials, leading to their utility across a broad spectrum of highperformance material applications....

A new method is proposed for estimation of cellulose crystallinity (CrI) based on 93 cm−1 Raman band in spectra of cellulose I materials. In this method (93-Raman), CrI was determined based on regression that was developed using the ratios of peak-heights of the 93 and 1096 cm−1 Raman bands (I93/I1096). For calibration purposes, a set of eight samples, all derived from cotton microcrystalline cellulose Whatman CC31 were selected. When the peak intensity ratios (I93/I1096) were plotted against the calculated CrIs of the calibration set samples, the plot showed an excellent linear correlation...

Two lignin-containing cellulose nanofibril (LCNF) samples, produced from two unbleached kraft pulps with very different lignin contents, were used to produce reinforced polyvinyl alcohol (PVA) hydrogels. The effects of LCNF loading (0.25−2wt %) and lignin content on the rheological and mechanical properties of the reinforced hydrogels were investigated. The 2 wt % LCNF-reinforced PVA hydrogels exhibited up to a 17-fold increase in storage modulus and a 4-fold increase in specific Young’s modulus over that of pure PVA hydrogel. Both the mechanical and rheological properties of LCNF-reinforce...

This publication supersedes FPL General Technical Report FPL-GTR-11, “Protecting Log Cabins from Decay” (1977), and FPL Report Number 982, “Making Log Cabins Endure: Suggestions on Construction, Log Selection, Preservation, and Finishing” (1974). These prior reports provided recommendations for preservative formulation and application that are not currently allowed under U.S. Environmental Protection Agency regulations. However, much of the information on log home construction and design remains of value and was transferred from those earlier reports. Additional information was added on...

This report identifies the priority areas in residential construction where technical research and technological advancements offer potential to benefit the industry as it strives to advance the quality of housing and meet today’s market expectations for a home’s cost, performance, durability, and environmental stewardship. The prioritization is performed by home builders based on their experience with constructing new homes.

The U.S. housing market’s quarter three indicated slight improvement from the second quarter, with the exception of multifamily construction. Improvement spending declined within the quarter, quarter-over-quarter, and year-over-year. Viewed from a recent historical context, all housing construction subsectors exceeded the record lows recorded in the 2008 to 2011 time period.