NANOlab Center of Excellence literature database -- Query Results

“Does leaf micro-morphology influence the recognition of particles on SEM images?”.Muhammad S, Wuyts K, De Wael K, Samson R, International Journal of Environmental Pollution and Remediation 9, 22 (2021). http://doi.org/10.11159/IJEPR.2021.003 Abstract: Scanning electron microscopy (SEM) remains a popular approach to determine the shape, size, density and elemental composition of particles collected on leaf surfaces, but the effect of leaf micro-morphology on particle counts is not very well known. In this study, leaves of sixteen urban plant species were examined for particle density in June and September 2016 using SEM. The investigated plant species differed in leaf micro-morphology involving trichomes, raised stomata, epicuticular wax crystals and convex epidermal cells forming deep grooves between cells. The particle density on leaves of the investigated plant species was estimated by particle size fraction and leaf side. Particle density was significantly higher on the adaxial (AD) leaf side compared to the abaxial (AB) leaf side and higher for fine-particles than coarse-particles. The effect of trichome density on particle density of the AB and the AD leaf side was indicated to be significant and positive for both coarse and fine-particles in June but not in September. The successive repeated measurements elucidated that features constructing the topography of a leaf surface such as trichomes, stomata, and epidermal cells frequently contributed towards the edge enhancement effect, resulting in exaggerated particle counts. Besides, the mechanical drift contributed to the disparity in particle density measurements. Lastly, the reduction in particle density between successive measurements were imputed on the charging effect. These results enable us to suggest that in addition to characterization of micro-morphological features on a leaf surface, SEM will continue to be a useful approach for determining the particle: shape, size, elemental composition and density of the deposited particles. Nonetheless, the disparity in particle density measurements can occur due to abnormal particle recognition. Based on the results of September, we recommend that within-session successive repeated measurements (~ n ≥ 5) need to be performed to remove measurement uncertainties and obtain reliable quantitative data of particle counts using SEM. Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) DOI: 10.11159/IJEPR.2021.003 Additional Links: UA library record show.php?record=7822
“Characterization of epicuticular wax structures on leaves of urban plant species and its association with leaf wettability”. Muhammad S, Wuyts K, Nuyts G, De Wael K, Samson R, Urban Forestry &, Urban Greening 47, 126557 (2020). http://doi.org/10.1016/J.UFUG.2019.126557 Abstract: Epicuticular wax (EW) protects the plant’s integrity and acts as a barrier against biotic and abiotic stresses. The micro-structured three-dimensional EW’s and presence of leaf trichomes influence the wettability of a leaf surface. In this study, leaves of 96 perennial urban plant species were examined to determine an association between epicuticular wax structure (EWS) types and leaf wettability and investigate their seasonal variation. The EWS types were identified using Scanning Electron Microscopy (SEM), while leaf wettability was analyzed by measuring the drop contact angle (DCA) on both the abaxial and the adaxial sides of leaves collected from a common garden in June and September 2016. Four distinct EWS types namely thin film, platelets, crusts, and tubules were observed on leaves of investigated plant species in both June and September. The EWS types varied significantly between functional plant types and plant families in both June and September. In June, the abaxial DCA ranged from 56° to 147°, and the adaxial DCA ranged from 56° to 136°. In September, the abaxial DCA ranged from 54° to 130°, and the adaxial DCA ranged from 51° to 125°. The effect of time, leaf side, and EWS type on leaf wettability were significant. Plant species which showed a change in EWS type or clustering from June to September did not show a more pronounced reduction in DCA compared to those species which exhibited a constant EWS type. Findings from our study illustrate that DCA is not a good indicator in determining the different EWS types due to overlapping DCA intervals between the identified EWS types. However, the identified EWS types remained fairly stable throughout the in-leaf season and do not require repeated measurements for characterization. Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) Impact Factor: 6.4 Times cited: 5 DOI: 10.1016/J.UFUG.2019.126557 Additional Links: UA library record; WoS full record; WoS citing articles show.php?record=5504

Abstract: Scanning electron microscopy (SEM) remains a popular approach to determine the shape, size, density and elemental composition of particles collected on leaf surfaces, but the effect of leaf micro-morphology on particle counts is not very well known. In this study, leaves of sixteen urban plant species were examined for particle density in June and September 2016 using SEM. The investigated plant species differed in leaf micro-morphology involving trichomes, raised stomata, epicuticular wax crystals and convex epidermal cells forming deep grooves between cells. The particle density on leaves of the investigated plant species was estimated by particle size fraction and leaf side. Particle density was significantly higher on the adaxial (AD) leaf side compared to the abaxial (AB) leaf side and higher for fine-particles than coarse-particles. The effect of trichome density on particle density of the AB and the AD leaf side was indicated to be significant and positive for both coarse and fine-particles in June but not in September. The successive repeated measurements elucidated that features constructing the topography of a leaf surface such as trichomes, stomata, and epidermal cells frequently contributed towards the edge enhancement effect, resulting in exaggerated particle counts. Besides, the mechanical drift contributed to the disparity in particle density measurements. Lastly, the reduction in particle density between successive measurements were imputed on the charging effect. These results enable us to suggest that in addition to characterization of micro-morphological features on a leaf surface, SEM will continue to be a useful approach for determining the particle: shape, size, elemental composition and density of the deposited particles. Nonetheless, the disparity in particle density measurements can occur due to abnormal particle recognition. Based on the results of September, we recommend that within-session successive repeated measurements (~ n ≥ 5) need to be performed to remove measurement uncertainties and obtain reliable quantitative data of particle counts using SEM.

Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)

DOI: 10.11159/IJEPR.2021.003

Additional Links: UA library record

show.php?record=7822

Abstract: Epicuticular wax (EW) protects the plant’s integrity and acts as a barrier against biotic and abiotic stresses. The micro-structured three-dimensional EW’s and presence of leaf trichomes influence the wettability of a leaf surface. In this study, leaves of 96 perennial urban plant species were examined to determine an association between epicuticular wax structure (EWS) types and leaf wettability and investigate their seasonal variation. The EWS types were identified using Scanning Electron Microscopy (SEM), while leaf wettability was analyzed by measuring the drop contact angle (DCA) on both the abaxial and the adaxial sides of leaves collected from a common garden in June and September 2016. Four distinct EWS types namely thin film, platelets, crusts, and tubules were observed on leaves of investigated plant species in both June and September. The EWS types varied significantly between functional plant types and plant families in both June and September. In June, the abaxial DCA ranged from 56° to 147°, and the adaxial DCA ranged from 56° to 136°. In September, the abaxial DCA ranged from 54° to 130°, and the adaxial DCA ranged from 51° to 125°. The effect of time, leaf side, and EWS type on leaf wettability were significant. Plant species which showed a change in EWS type or clustering from June to September did not show a more pronounced reduction in DCA compared to those species which exhibited a constant EWS type. Findings from our study illustrate that DCA is not a good indicator in determining the different EWS types due to overlapping DCA intervals between the identified EWS types. However, the identified EWS types remained fairly stable throughout the in-leaf season and do not require repeated measurements for characterization.