Methods for characterization of nanoparticles

Kumar, Ajeet; Dixit, Chandra Kumar

doi:10.1016/b978-0-08-100557-6.00003-1

Cited by 325 publications

(210 citation statements)

References 53 publications

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“…In terms of zeta potential (Table 1; top), all cellulose derivatives led to negatively charged particles, with average values around -29 mV. This result suggests moderate stability of the suspensions, meaning that the propensity to aggregate might not be a critical issue (Torchilin 2006;Kumar and Dixit 2017).…”

Section: Resultsmentioning

confidence: 96%

Eugenol-loaded microspheres incorporated into textile substrates

et al. 2020

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This work reports studies on the production of eugenol-loaded microspheres by solvent evaporation method, targeted for incorporation into textile substrates, using different cellulose derivatives: ethyl cellulose, cellulose acetate (CA), cellulose butyrate acetate, and cellulose acetate phthalate. The microspheres were evaluated in terms of size, shape, thermal stability, encapsulation efficiency, and eugenol kinetics release. CA-based microspheres proved to be the best, thus being selected for subsequent experiments. Comparable properties of the CA-based microspheres were achieved ongoing from 100 mL to higher batch volumes (up to 2000 mL). The eugenol-loaded microspheres were successfully incorporated into cotton fabrics using a padding technique, confirmed by FE-SEM. Eugenol release profiles from the impregnated textiles demonstrated a slow and controlled release (less than 20% of the encapsulated amount over 90 days). The developed microspheres demonstrated to be the most promising for the retention and protection of hydrophobic active compounds for possible textile applications.

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Section: Resultsmentioning

confidence: 96%

Eugenol-loaded microspheres incorporated into textile substrates

et al. 2020

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“…The surface charge of PVP-AgNPs and the physical stability of the colloidal nanodispersions were estimated by surface zeta potential (ζ) measurements ( Table 1). The ζ values express the electrical charge between the moving and stationary layers around colloidal particles [32]. Thus, it is possible to predict PVP-AgNPs stability and their ability to interact with a textile substrate.…”

Section: Dynamic Light Scattering (Dls)mentioning

confidence: 99%

Effect of Dispersion Solvent on the Deposition of PVP-Silver Nanoparticles onto DBD Plasma-Treated Polyamide 6,6 Fabric and Its Antimicrobial Efficiency

et al. 2020

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Polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) dispersed in ethanol, water and water/alginate were used to functionalize untreated and dielectric barrier discharge (DBD) plasma-treated polyamide 6,6 fabric (PA66). The PVP-AgNPs dispersions were deposited onto PA66 by spray and exhaustion methods. The exhaustion method showed a higher amount of deposited AgNPs. Water and water-alginate dispersions presented similar results. Ethanol amphiphilic character showed more affinity to AgNPs and PA66 fabric, allowing better uniform surface distribution of nanoparticles. Antimicrobial effect in E. coli showed good results in all the samples obtained by exhaustion method but using spray method only the DBD plasma treated samples displayed antimicrobial activity (log reduction of 5). Despite the better distribution achieved using ethanol as a solvent, water dispersion samples with DBD plasma treatment displayed better antimicrobial activity against S. aureus bacteria in both exhaustion (log reduction of 1.9) and spray (methods log reduction of 1.6) due to the different oxidation states of PA66 surface interacting with PVP-AgNPs, as demonstrated by X-ray Photoelectron Spectroscopy (XPS) analysis. Spray method using the water-suspended PVP-AgNPs onto DBD plasma-treated samples is much faster, less agglomerating and uses 10 times less PVP-AgNPs dispersion than the exhaustion method to obtain an antimicrobial effect in both S. aureus and E. coli.

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“…The anomalous exponent (α) ranged from strongly subdiffusive (α ≈ 0.1) to purely diffusive (α ≈ 1), but it was obtained only for a third of the dataset (n = 33, 30%). The zeta potential (ζ) measured the effective surface charge of particles in solution (Kumar and Dixit 2017). The values ranged from −70 mV to +40 mV and were obtained for half of the dataset (n = 57, 52%).…”

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confidence: 99%

Unifying framework for the diffusion of microscopic particles in mucus

Cobarrubia

Tall

Crispin-Smith

et al. 2020

Preprint

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Mucus is a fluid that protects animals against pathogens while promoting interactions with commensal microbes. Changes in the diffusivity of particles in mucus alter viruses’ infectivity, the efficiency of bacterial pathogens to invade a host, and the effectivity of drug delivery. Multiple physicochemical properties modulate the diffusion of microscopic particles in mucus, but their combined effect is unclear. Here, we analyzed the impact of particle size, charge, chemistry, anomalous diffusion exponent, and mucus composition in the diffusivity of particles from 106 published experiments. We used a time window sampling of one second to define a consistent, effective diffusion across experiments. The effective diffusion spanned seven orders of magnitude from 10−5 to 102 µm2/s. The anomalous exponent was the strongest predictor among all variables tested. It displayed an exponential relationship with the effective diffusion that explained 90% of the empirical data variance. We showed that the relationship and dominance of the anomalous diffusion exponent resulted from a general mathematical relationship obtained from first-principles for any subdiffusion mechanism. Our derivation demonstrated that the generalized diffusion coefficient is not a measurable physical quantity and must be replaced by the length and time scales associated with the underlying mobility mechanisms. This led us to a fundamental reformulation of the classic subdiffusion equation, which calls for a reinterpretation of anomalous diffusion in physical systems. We also discussed how our results impact the characterization of microscopic particle diffusion in mucus and other hydrogels.

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Methods for characterization of nanoparticles

Cited by 325 publications

References 53 publications

Eugenol-loaded microspheres incorporated into textile substrates

Eugenol-loaded microspheres incorporated into textile substrates

Effect of Dispersion Solvent on the Deposition of PVP-Silver Nanoparticles onto DBD Plasma-Treated Polyamide 6,6 Fabric and Its Antimicrobial Efficiency

Unifying framework for the diffusion of microscopic particles in mucus

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