Room temperature phosphorescence from natural wood activated by external chloride anion treatment

Abstract

Producing afterglow room temperature phosphorescence (RTP) from natural sources is an attractive approach to sustainable RTP materials. However, converting natural resources to RTP materials often requires toxic reagents or complex processing. Here we report that natural wood may be converted into a viable RTP material by treating with magnesium chloride. Specifically, immersing natural wood into an aqueous MgCl2 solution at room temperature produces so-called C-wood containing chloride anions that act to promote spin orbit coupling (SOC) and increase the RTP lifetime. Produced in this manner, C-wood exhibits an intense RTP emission with a lifetime of ~ 297 ms (vs. the ca. 17.5 ms seen for natural wood). As a demonstration of potential utility, an afterglow wood sculpture is prepared in situ by simply spraying the original sculpture with a MgCl2 solution. C-wood was also mixed with polypropylene (PP) to generate printable afterglow fibers suitable for the fabrication of luminescent plastics via 3D printing. We anticipate that the present study will facilitate the development of sustainable RTP materials.

3D-Printable Room Temperature Phosphorescence Polymer Materials with On-Demand Modulation for Modulus Visualization and Anticounterfeiting Applications

“…3D-printable RTP materials are of interest due to the growing demand for irregular shapes and multimaterial structures. , 3D printing, also known as additive manufacturing (AM), has become an advanced and versatile technology for rapid on-demand fabrication of solid objects . Unlike traditional manufacturing processes, additive manufacturing tools can produce arbitrarily complex shapes characterized by layered and intricate structures, featuring hollow features and multimaterial structures.…”

Microwave‐Responsive Flexible Room‐Temperature Phosphorescence Materials Based on Poly(vinylidene fluoride) Polymer

“…The triplet excitons from organic phosphors are unstable at room temperature, therefore, a polymer matrix is required to provide a rigid environment. A rigid environment reduces the segmental motion, thus lowering nonradiative transitions ( K nr ) and stabilizing the triplet excitons [18–24] . Therefore, the polymers with glass‐transition temperature ( T g ) higher than the room temperature, such as syndiotatic poly(methyl methacrylate) (PMMA) ( T g =115 °C), poly(vinyl alcohol) (PVA) ( T g =85 °C), polystyrene (PS) ( T g =100 °C), polyacrylonitrile (PAN) ( T g =104 °C), polyacrylic acids (PAA) ( T g =106 °C), and ethyl cellulose ( T g =53 °C), were extensively employed as the RTP matrices in the previous reports.…”

“…A rigid environment reduces the segmental motion, thus lowering nonradiative transitions (K nr ) and stabilizing the triplet excitons. [18][19][20][21][22][23][24] Therefore, the polymers with glasstransition temperature (T g ) higher than the room temperature, such as syndiotatic poly(methyl methacrylate) (PMMA) (T g = 115 °C), poly(vinyl alcohol) (PVA) (T g = 85 °C), polystyrene (PS) (T g = 100 °C), polyacrylonitrile (PAN) (T g = 104 °C), polyacrylic acids (PAA) (T g = 106 °C), and ethyl cellulose (T g = 53 °C), were extensively employed as the RTP matrices in the previous reports. Additionally, the introduction of hydrogen/halogen bonding and sidechain grafting between the polymer and phosphor was required to restrict the molecular motion of the phosphors (Figure 1a).…”

Activating the Room-Temperature Phosphorescence of Organic Dyes through the Confinement Effect of Delignified Wood

“…34 However, the major drawback lies in the untunable emission profiles of lignin, severely constraining the advancement and practical applications of RTP materials derived from natural wood. 31,32 Notably, the delignified wood (DW) templates, characterized by nanoscale pores, offer a remarkable opportunity for creating encapsulated composites with luminescent materials. 35−41 This approach holds the potential to produce composite luminescent materials with adjustable photophysical properties.…”

“…Wood is a renewable biomass material that has been widely used in functional composites due to its unique hierarchically porous structure, natural abundance, excellent mechanical property, and low cost. − Remarkably, natural wood exhibits RTP properties, positioning it as a highly promising candidate for RTP materials. − The RTP phenomenon in natural wood arises from its constituent lignin, which is a naturally occurring aromatic polymer. More importantly, the presence of the wood cell wall structure and intrinsic cellulose/hemicellulose matrix confines and stabilizes the triplet states of lignin, constituting the primary reason for its RTP behavior .…”