Analysis of different approaches for evaluation of surface energy of microbial cells by contact angle goniometry

Sharma, Prashant K.; Rao, K. Hanumantha

doi:10.1016/s0001-8686(02)00004-0

Cited by 284 publications

(244 citation statements)

References 95 publications

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“…The induced hydrophilicity upon multistep modifications is surmised to stem from the formation of hydrophilic groups on the surface in particular in the case of sample 3 [33][34][35]. To delve further into the surface physicochemical variations of the samples, a widely used theory, Lifshitz-van der Waals/acid-base (LW/AB) [36], has been employed to estimate free surface energy values whose outputs based on diiodomethane, ethylene glycol, and deionized water as wetting agents are given in Table 1. As suggested by the data, sample 1 shows a basic nature (Y~ > X + ).…”

Section: Surface Wettability Analysismentioning

confidence: 99%

“…As suggested by the data, sample 1 shows a basic nature (Y~ > X + ). however acidity or basicity of neat PVC has been a matter of dispute [ 1,36,37]. Upon treating with plasma (sample 2), the total surface free energy (y tot ) increases concerning an evident change in contact angle values.…”

Section: Surface Wettability Analysismentioning

confidence: 99%

“…Sample 6 exhibits the minimum hydrophilicity and y tot compared to samples 4 and 5. To draw a parallel between LW/AB theory and equation of state models, the predictions for surface free energy values of samples 1-6 based on three equation of state models [36] (Kwok-Neumann, Li-Neumann, and Wu) using four wetting agents are reported in Table 1. Although they yield lower outputs compared to LW/AB approach, the variation trend indicated from samples 1 to 6 is maintained.…”

Section: Surface Wettability Analysismentioning

confidence: 99%

“…a Surface free energy value according to Wu equation of state [36]. b Surface free energy value according to Kwok-Neumann model [36].…”

Section: Surface Wettability Analysismentioning

confidence: 99%

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An in vitro bacterial adhesion assessment of surface-modified medical-grade PVC

Asadinezhad

Novák

Lehocký

et al. 2010

Colloids and Surfaces B: Biointerfaces

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A B S T R A C TMedical-grade polyvinyl chloride was surface modified by a multistep physicochemical approach to improve bacterial adhesion prevention properties. This was fulfilled via surface activation by diffuse coplanar surface barrier discharge plasma followed by radical graft copolymerization of acrylic acid through surfaceinitiated pathway to render a structured high density brush. Three known antibacterial agents, bronopol, benzalkonium chloride, and chlorhexidine, were then individually coated onto functionalized surface to induce biological properties. Various modern surface probe techniques were employed to explore the effects of the modification steps. In vitro bacterial adhesion and biofilm formation assay was performed. Escherichia coli strain was found to be more susceptible to modifications rather than Staphylococcus aureus as up to 85% reduction in adherence degree of the former was observed upon treating with above antibacterial agents, while only chlorhexidine could retard the adhesion of the latter by 50%. Also, plasma treated and graft copolymerized samples were remarkably effective to diminish the adherence of E. coli.

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Section: Surface Wettability Analysismentioning

confidence: 99%

Section: Surface Wettability Analysismentioning

confidence: 99%

Section: Surface Wettability Analysismentioning

confidence: 99%

“…a Surface free energy value according to Wu equation of state [36]. b Surface free energy value according to Kwok-Neumann model [36].…”

Section: Surface Wettability Analysismentioning

confidence: 99%

See 2 more Smart Citations

An in vitro bacterial adhesion assessment of surface-modified medical-grade PVC

Asadinezhad

Novák

Lehocký

et al. 2010

Colloids and Surfaces B: Biointerfaces

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“…The selective separation of sphalerite from pyrite has been studied in the presence of Acidobacillus ferrooxidans [20]. The surface energies of 140 bacterial and seven yeast cell surfaces following Fowkes, Equation of state and Geometric mean and Lifshitz-van der Waals acid-base (LW-AB) approaches have been extensively studied and evaluated by Rao et al [21].…”

Section: Bio-separation Processesmentioning

confidence: 99%

Biocoagulation and its Application Potentials for Mineral Bioprocessing

Kuyumcu

Bielig²,

Vilinska³

et al. 2009

TOMPJ

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Summary:The well-known sorting processes like density separation, separation in magnetic or electric fields and flotation, are not suitable to apply successfully within a particle-size range smaller than 10 m. Due to insufficient selectivity of above mentioned enrichment processes the concentrate recovery at this particle size range is extremely poor, which influences accordingly the techno-economic efficiency of mineral processing negative.Based on a process design idea, investigations confirm that the biocoagulation of microorganisms and solid particles can be used to generate coarser sized coagulates which are more suitable for sorting. Experimental investigations showed that microorganisms like Saccharomyces cerevisiae and Yarrowia lipolytica and sulphide particles like galena and sphalerite below 10 m coagulate effectively. Theoretical thermodynamic and extended DLVO theory calculations are in good agreement with microorganisms adhesion onto metal sulphides but not on silicates and selective biocoagulation of sulphides. Furthermore it has been demonstrated that flotation is suitable for the separation of the selectively formed biocoagulates.

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Expanded Bed Chromatography, Surface Energetics of Biomass Deposition

Fernández‐Lahore

Aguilar

Vennapusa

et al. 2010

Encyclopedia of Industrial Biotechnology

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The introduction of Expanded Bed Adsorption (EBA) system has made biochemical engineers face the challenge of operating a “chromatography” in the presence of biomass and other particulate components which are normally present in a crude, unclarified, feedstock. This situation can lead to detrimental consequences in terms of increased adsorbent fouling, decreased adsorbent binding capacity, and poor bed hydrodynamics. Biomass and other suspended biological material can be very sticky, depending on the type of adsorbent employed and the solution chemistry involved and thus, can create severe limitations during processing. A better local understanding of biomass deposition, including the two separate cell‐to‐bead (“interaction”) and cell‐to‐cell (“aggregation”) phenomena has been developed to allow for safer EBA operations. To this end, we propose a surface energetics‐based approach. As per the XDLVO theory, free interfacial energy versus distance profiles were calculated for a large combination of model biomass and adsorbent bead types. The energy minima values (absolute value/ U ) obtained for each of the analyzed cases were correlated with the corresponding deposition coefficient values (α). A positive correlation was obtained. It was concluded that total interaction energy U ≤ − 25 to − 50 kT and biomass deposition parameter α ≤ 0.15 would be a safe region for EBA operation; for example, biomass interference can be neglected. Deviation in the correlation was found in such cases where moderate or high cell‐to‐cell aggregation occurs, for example, in hydrophobic interaction systems. In the later cases, laser diffraction studies were necessary to fully characterize the system. These novel tools will help in alleviating the current EBA technical constraints and will guide the design of more efficient adsorbent types.

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Analysis of different approaches for evaluation of surface energy of microbial cells by contact angle goniometry

Cited by 284 publications

References 95 publications

An in vitro bacterial adhesion assessment of surface-modified medical-grade PVC

An in vitro bacterial adhesion assessment of surface-modified medical-grade PVC

Biocoagulation and its Application Potentials for Mineral Bioprocessing

Expanded Bed Chromatography, Surface Energetics of Biomass Deposition

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