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Wednesday, 31 August 2016

Water-repellent coatings prepared by modification of ZnO nanoparticles

Published Date
August 2012, Vol.94:352–356, doi:10.1016/j.saa.2012.03.079
Short communication

Title 

Water-repellent coatings prepared by modification of ZnO nanoparticles

  • Author 
  • R.P.S. Chakradhar ,,
  • V. Dinesh Kumar
  • Surface Engineering Division, CSIR-National Aerospace Laboratories, Bangalore 560017, India
Received 22 January 2012. Revised 18 March 2012. Accepted 25 March 2012. Available online 2 April 2012.

 Abstract 

 Superhydrophobic coatings with a static water contact angle (WCA) > 150° were prepared by modifying ZnO nanoparticles with stearic acid (ZnO@SA). ZnO nanoparticles of size ∼14 nm were prepared by solution combustion method. X-ray diffraction (XRD) studies reveal that as prepared ZnO has hexagonal wurtzite structure whereas the modified coatings convert to zinc stearate. Field emission scanning electron micrographs (FE-SEM) show the dual morphology of the coatings exhibiting both particles and flakes. The flakes are highly fluffy in nature with voids and nanopores. Fourier transformed infrared (FTIR) spectrum shows the stearate ion co-ordinates with Zn2+ in the bidentate form. The surface properties such as surface free energy (γp) and work of adhesion (W) of the unmodified and modified ZnO coatings have been evaluated. The electron paramagnetic resonance (EPR) spectroscopy reveals that surface defects play a major role in the wetting behavior.

 Graphical abstract 

 FE-SEM micrographs of superhydrophobic ZnO@SA coating with different magnification (a) 4k×, (b) magnified view of (zone A) 20k×, (c) magnified view of (zone B) 20k× and (d) 25k×.

Highlights

► Water repellent coatings were prepared by modifying ZnO nanoparticles. ► Surface properties of the coatings were evaluated. ► EPR spectroscopy reveals that surface defects play a major role in wetting behavior.

Keywords

  • ZnO
  • Superhydrophobic
  • XRD
  • FE-SEM
  • Water contact angle
  • Electron paramagnetic resonance
Fig. 1.
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 Table 1
Table 1.

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Plectranthus amboinicus leaf extract–assisted biosynthesis of ZnO nanoparticles and their photocatalytic activity

Published Date
March 2015, Vol.41(2):2492–2496, doi:10.1016/j.ceramint.2014.10.069

Title 

Plectranthus amboinicus leaf extract–assisted biosynthesis of ZnO nanoparticles and their photocatalytic activity

  • Author 
  • Li Fu a,b,,
  • Zhuxian Fu b
  • aInstitute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing Botanical Garden, Mem. Sun Yat-Sen, Nanjing 210014 P. R. China
  • bGolden Yuanta Construction Engineering Co., Ltd, Zhejiang 311200, China
Received 10 October 2014. Revised 12 October 2014. Accepted 12 October 2014. Available online 28 October 2014.

Abstract

This article demonstrates the synthesis of ZnO nanoparticles (NPs) using leaf extract of Plectranthus amboinicus. The synthesized ZnO NPs were characterized by UV–vis spectroscopy, SEM, EDX, XRD, FTIR and photoluminescence spectroscopy. SEM study reveals that the biosynthesized ZnO NPs exhibits a rod shape structure with an average size of 88 nm. The UV–vis diffuse reflectance spectrum study indicates the band gap of biosynthesized ZnO NPs is 3.07 eV. Photocatalytic property of the ZnO NPs was investigated by photodegradation of methyl red (MR) under UV illumination. The photocatalytic performance of biosynthesized ZnO NPs was compared with hydrothermal synthesized ZnO NPs and P25. Results show that the biosynthesized ZnO NPs owing a superior photocatalytic activity towards degradation of MR.

Keywords

  • Biosynthesis
  • ZnO nanoparticles
  • Plectranthus amboinicus
  • Photodegradation
    • Fig. 1.
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    • ⁎ 
      Corresponding author at: Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing Botanical Garden, Mem. Sun Yat-Sen, Nanjing 210014 P. R. China.


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    Genetic variability and recombination analysis of the coat protein gene of Strawberry mild yellow edge virus

    Published Date
    , Volume 45, Issue 4, pp 401–409


    Title 

    Genetic variability and recombination analysis of the coat protein gene of Strawberry mild yellow edge virus

    • Author 
    • A. K. Torrico, 
    • M. G. Celli, 
    • E. E. Cafrune, 
    • D. S. Kirschbaum, 
    Original Paper
    First Online: 
    06 July 2016
    DOI: 10.1007/s13313-016-0426-3


    Cite this article as: 
    Torrico, A.K., Celli, M.G., Cafrune, E.E. et al. Australasian Plant Pathol. (2016) 45: 401. doi:10.1007/s13313-016-0426-3

    Abstract

    Strawberry mild yellow edge virus (SMYEV) has been detected in most of the strawberry production regions worldwide. However, little is known about differences between distinct isolates. The aim of this study was to enhance the knowledge about the genetic variability of different SMYEV isolates, exploring the phylogenetic relationships and assessing recombinant events among them. The coat protein (CP) gene of 12 Argentinian SMYEV isolates was sequenced. There were 729 nucleotides (nt) in all of the isolates, encoding a protein of 242 amino acids (aa). Argentina isolates shared 81.5–99.6 % nucleotide identity. The comparison of these isolates with 30 SMYEV sequences from other countries published in the GenBank, revealed an identity ranging from 81.6 to 99 %. The phylogenetic analysis showed the presence of four possible subgroups, with the Argentinian isolates being included in all of them. Recombination analysis indicated that 16–2 (KP 284155) Argentinian and AJ577342 Chilean isolates are recombinant and that they are a result of recombination events where parts of the genome were exchanged between different SMYEV sequences.

    References







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    An assessment of Pythium spp. associated with soft rot disease of ginger (Zingiber officinale) in Queensland, Australia

    Published Date
    , Volume 45, Issue 4, pp 377–387

    Title 

    An assessment of Pythium spp. associated with soft rot disease of ginger (Zingiber officinale) in Queensland, Australia




    Original Paper
    First Online: 
    24 June 2016
    DOI: 10.1007/s13313-016-0424-5

    Cite this article as: 
    Le, D.P., Smith, M.K. & Aitken, E.A.B. Australasian Plant Pathol. (2016) 45: 377. doi:10.1007/s13313-016-0424-5

    Abstract

    In Australia, Pythium soft rot (PSR) outbreaks caused by P. myriotylum were reported in 2009 and since then this disease has remained as a major concern for the ginger industry. From 2012 to 2015, a number of Pythium spp. were isolated from ginger rhizomes and soil from farms affected by PSR disease and assessed for their pathogenicity on ginger. In this study, 11 distinct Pythium spp. were recovered from ginger farms in Queensland, Australia and species identification and confirmation were based on morphology, growth rate and ITS sequences. These Pythium spp. when tested showed different levels of aggressiveness on excised ginger rhizome. P. aphanidemartum, P. deliense, P. myriotylum, P. splendens, P. spinosum and P. ultimum were the most pathogenic when assessed in vitro on an array of plant species. However, P. myriotylum was the only pathogen, which was capable of inducing PSR symptoms on ginger at a temperature range from 20 to 35 °C. Whereas, P. aphanidermatum only attacked and induced PSR on ginger at 30 to 35 °C in pot trials. This is the first report of P. aphanidermatum inducing PSR of ginger in Australia at high temperatures. Only P. oligandrum and P. perplexum, which had been recovered only from soils and not plant tissue, appeared non-pathogenic in all assays.

    References

    1. Bahramisharif A, Lamprecht SC, Spies CFJ, Botha WJ, Calitz FJ, McLeod A (2013) Pythiumspp. associated with rooibos seedlings, and their pathogenicity toward rooibos, lupin, and oat. Plant Dis 98:223–232CrossRef
    2. Butler EJ (1907) An account of the genus Pythium and some Chytridiaceae. Memoirs of the Department of Agriculture, India (Botanical Series) 1:70
    3. Camacho HE, Brescia A (2009) The Australian ginger industry: overview of market trends and oppotunities. Department of Employment, Economic Development and Innovation, The State of Queensland, p. 54
    4. Chellemi DO, Mitchell DJ, Kannwischer-Mitchell ME, Rayside PA, Rosskopf EN (2000) Pythium spp. associated with bell pepper production in Florida. Plant Dis 84:1271–1274CrossRef
    5. Dhingra OD, Sinclair JB (1995) Basic plant pathology methods, 2nd edn. CRC Press, United States of America
    6. Dick MW (1990) Keys to Pythium. The College of Estate Management. Whiteknights, Reading, Great Britain
    7. Dohroo NP (2001) Etiology and management of storage rot of ginger in Himachal Pradesh. Indian Phytopathol 54:49–54
    8. Dohroo NP (2005) Diseases of ginger. In: Ravindran PN, Babu KN (eds) Ginger, the genus Zingiber. CRC Press, Boca Raton, pp. 305–340
    9. Doyle JJ, Doyle JL (1990) Isolation of plant DNA from fresh tissue. Focus 12:13
    10. Gerbore J, Benhamou N, Vallance J, Le Floch G, Grizard D, Regnault-Roger C, Rey P (2014) Biological control of plant pathogens: advantages and limitations seen through the case study of Pythium oligandrum. Environ Sci Poll Res 21:4847–4860CrossRef
    11. Hogarth J (2000) Buderim ginger: an export success story : a history of the ginger industry of Queensland. Hogarth & Buderim Ginger Ltd, Yandina, Qld
    12. Kavitha PG, Thomas G (2008) Expression analysis of defense-related genes in Zingiber (Zingiberaceae) species with different levels of compatibility to the soft rot pathogen Pythium aphanidermatum. Plant Cell Rep 27:1767–1776CrossRefPubMed
    13. Kim CH, Yang SS, Park KS (1997) Pathogencity and mycological characteristics of Pythium myriotylum causing rhizome rot of ginger. Korean J Plant Pathol 13(3):152–157
    14. Kroon LPNM, Bakker FT, van den Bosch GBM, Bonants PJM, Flier WG (2004) Phylogenetic analysis of Phytophthora species based on mitochondrial and nuclear DNA sequences. Fungal Genet Biol 41:766–782CrossRefPubMed
    15. Kumar A, Reeja ST, Bhai RS, Shiva KN (2008) Distribution of Pythium myriotylumDrechsler causing soft rot of ginger. JOSAC 17(1):5–10
    16. Le PD, Smith MK, Aitken EAB (2010) Pythium spp. on ginger (Zingiber officinale Roscoe) in Australia. In: Sterling GR (ed) 6th ASDS Proceedings, Twin Waters, Queensland, p. 62
    17. Le DP, Smith M, Hudler GW, Aitken E (2014) Pythium soft rot of ginger: detection and identification of the causal pathogens, and their control. Crop Prot 65:153–167
    18. Le DP, Smith MK, Aitken EAB (2015) Pythiogeton ramosum, a new pathogen of soft rot disease of ginger (Zingiber officinale) at high temperatures in Australia. Crop Prot 77:9–17CrossRef
    19. Levesque CA, De Cock AWAM (2004) Molecular phylogeny and taxonomy of the genus Pythium. Mycol Res 108:1363–1383CrossRefPubMed
    20. Li Y, Mao LG, Yan DD, Liu XM, Ma TT, Shen J, Liu PF, Li Z, Wang QX, Ouyang CB, Guo MX, Cao AC (2014a) First report in China of soft rot of ginger caused by Pythium aphanidermatum. Plant Dis 98:1011CrossRef
    21. Li YP, You MP, Barbetti MJ (2014b) Species of Pythium associated with seedling root and hypocotyl disease on common bean (Phaseolus vulgaris) in Western Australia. Plant Dis 98:1241–1247CrossRef
    22. Lumsden RD, Ayers WA, Dow RL (1975) Differential isolation of Pythium species from soil by means of selective media, temperature and pH. Can J Microbiol 21:606–612CrossRef
    23. Martin FN (2000) Phylogenetic relationships among some Pythium species inferred from sequence analysis of the mitochondrially encoded cytochrome oxidase II gene. Mycologia 92:711–727CrossRef
    24. McLeod A, Botha WJ, Meitz JC, Spies CFJ, Tewoldemedhin YT, Mostert L (2009) Morphological and phylogenetic analyses of Pythium species in South Africa. Mycol Res 113:933–951CrossRefPubMed
    25. Mu JH, Bollon AP, Sidhu RS (1999) Analysis of β-tubulin cDNAs from taxol-resistant Pestalotiopsis microspora and taxol-sensitive Pythium ultimum and comparison of the taxol-binding properties of their products. Mol Gen Genet 262:857–868CrossRefPubMed
    26. Perneel M, Tambong JT, Adiobo A, Floren C, Saborío F, Lévesque A, Höfte M (2006) Intraspecific variability of Pythium myriotylum isolated from cocoyam and other host crops. Mycol Res 110:583–593CrossRefPubMed
    27. van der Plaats-Niterink AJ (1981) Monograph of the genus Pythium. Studies of Mycology 21:1–244
    28. Robideau GP, Gachon CMM, Hu C-H, Küpper FC, Rintoul TL, Sarhan E, Verstappen ECP, Zhang Y, Bonants PJM, Ristaino JB, Lévesque CA, De Cock AWAM, Coffey MD, Voglmayr H, Brouwer H, Bala K, Chitty DW, Désaulniers N, Eggertson QA (2011) DNA barcoding of oomycetes with cytochrome c oxidase subunit I and internal transcribed spacer. Mol Ecol Resour 11:1002–1011CrossRefPubMedPubMedCentral
    29. Stanghellini ME, Kronland WC (1985) Bioassay for quantification of Pythium aphanidermatum in soil. Phytopathology 75:1242–1245CrossRef
    30. Stirling GR, Turaganivalu U, Stirling AM, Lomavatu MF, Smith MK (2009) Rhizome rot of ginger (Zingiber officinale) caused by Pythium myriotylum in Fiji and Australia. Australas Plant Pathol 38:453–460CrossRef
    31. Teakle DS (1962) Investigation on the genus Pythium in Queensland. The University of Queensland, Master theis of Agricultural Science
    32. Tsai YP (1991) List of plant disease in Taiwan. The plant protection society of the republic of China and the Phytopathological society of the republic of China. Taichung, Taiwan
    33. Wang PH, Chang CW (2003) Detection of the low-germination-rate resting oospores of Pythium myriotylum from soil by PCR. Lett Appl Microbiol 36:157–161CrossRefPubMed
    34. White TJ, Bruns T, Lee S, Taylor J (1990) Amplification and Direct Sequencing of Fungal Ribosomal RNA Genes for Phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (eds) PCR Protocols: a Guide to Methods and Applications. Academic Press, Inc., California, pp. 315–322
    35. Zhang BQ, Yang XB (2000) Pathogenicity of Pythium populations from corn-soybean rotation fields. Plant Dis 84:94–99CrossRef
    36. Zitnick-Anderson KK, Nelson BD (2014) Identification and pathogenicity of Pythium on soybean in North Dakota. Plant Dis 99:31–38CrossRef
    37. Yuan JD, Zhang YL, Qi JS, Zhang B, Xu ZT, Li L, Li CS (2013) Pathogen identification of ginger stalk rot from Shandong province. Acta Phytopath Sin 43:S525

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