Introducing lanthanide metal–organic framework and perovskite onto pulp fibers for fluorescent anti-counterfeiting and encryption

Photo-functionalized metal–organic frameworks for anti-counterfeiting applications

“…The fluorescent centers of PMOFs not only increase, but the position, peak width and intensity of the fluorescent centers also change by regulating the excitation wavelength to exhibit different encrypted patterns. 75,76 There are two main ways to prepare PMOFs with multiple fluorescent centers. First, the skeletons of the PMOFs contain multiple fluorescent components (multiple organic ligands, multiple lanthanide ions, and multiples of both), and these components have different energy transfer pathways under different excitation.…”

Cellulose as an Eco-Friendly and Sustainable Material for Optical Anticounterfeiting Applications: An Up-to-Date Appraisal

“…They display narrow absorption/emission bands covering the visible and near-infrared (NIR) regions, broad-range and intense fluorescence, high color purity, long fluorescence lifetime, relatively low toxicity, dopant ion-based multicolor and up-conversion luminescence, high resistance to photobleaching, as well as temperature and pressure treatment, favorable structural, optoelectronic, and magnetic features. 70 − 72 …”

“…Luminescent complexes based on trivalent lanthanide (Ln) ions have emerged as competing candidates for anticounterfeiting applications during the past decade, attributed to their fascinating properties. They display narrow absorption/emission bands covering the visible and near-infrared (NIR) regions, broad-range and intense fluorescence, high color purity, long fluorescence lifetime, relatively low toxicity, dopant ion-based multicolor and up-conversion luminescence, high resistance to photobleaching, as well as temperature and pressure treatment, favorable structural, optoelectronic, and magnetic features. − …”

A multi-stimuli-responsive CsPbBr3@PL-MOF functional anti-counterfeiting material

“…Recently, stimuli-responsive materials [1][2][3][4] are much more attractive as they have capabilities to adapt their intrinsic properties in response to multiple external stimuli, thus can be applied to intelligent detection, 5,6 document encryption systems, 7,8 or highlevel anti-counterfeiting displays. 9,10 However, progress has been relatively slow in developing multi-stimuli-responsive smart responsive materials. In this process, designing and selecting appropriate molecules with the ability to response to multiple stimuli are key to achieving this goal.…”

“…Among them, CsPbX 3 has shown luminescent changes upon different external stimuli, including water, PbX 2 , and amines in previously reported work. 9,[29][30][31] However, the reversible transformation between different composition and phase changes is still very difficult to achieve due to irreversible damage of the crystal structures as well as the luminescent properties. [32][33][34][35] In particular, there are still limited reports on its hydrochromic properties, which may be due to the poor stability of this perovskite material to water, resulting in irreversibility of color or PL emission.…”