Publications de Juan Kiwi | EPFL Graph Search

Publications associées (116)

TiO2 nanoparticles suppress Escherichia coli cell division in the absence of UV irradiation in acidic conditions

TiO2 nanoparticles (NPs) activated by UV irradiation are known to have a bactericidal effect. In this study we report the details of TiO2 NPs influence on the colony-forming capacity of E. coli in the dark at pH 4.0-4.5. At this pH the bacterial cells are ...

2012

Self-cleaning modified TiO2-cotton pretreated by UVC-light (185 nm) and RF-plasma in vacuum and also under atmospheric pressure

César Pulgarin, Juan Kiwi

Two new innovative findings presented in this study are: (a) TiO2-cotton fabrics obtained by pretreatment with UVC-light (185nm) at atmospheric pressure introduced functionalities into the cotton surface enabling the chelation/binding of TiO2. This was pos ...

2009

Insight into the interaction of magnetic photocatalysts with the incoming light accelerating bacterial inactivation and environmental cleaning

Juan Kiwi, Sami Rtimi

This report presents an up-to-date review on the interaction of light with magnetic semiconductors during photocatalysis leading to bacterial inactivation and pollutant degradation. The acceleration in the photocatalytic reactions mediated by wide-band gap ...

ELSEVIER2021

Duality in the Mechanism of Hexagonal ZnO/CuxO Nanowires Inducing Sulfamethazine Degradation under Solar or Visible Light

César Pulgarin, Juan Kiwi, Sami Rtimi

This study presents the first evidence for the photocatalytic performance of ZnO/CuxO hexagonal nanowires leading to sulfamethazine (SMT) degradation. The chemical composition of the nanowires was determined by X-ray fluorescence (XRF). The sample with the ...

2019

Antimicrobial Cu-functionalized surfaces prepared by bipolar asymmetric DC-pulsed magnetron sputtering (DCP)

César Pulgarin, Juan Kiwi, Rosendo Sanjines, Cristina del Socorro Lonfat

Cu-cotton fabrics were functionalized by bipolar asymmetric DC-pulse magnetron sputtering (DCP). The DCP of Cu-particles on cotton proceeds at a higher energy than DC-magnetron sputtering (DC). The different sputtering mode showed effects on the structure ...

2011

Innovative UVC Light (185 nm) and Radio-Frequency-Plasma Pretreatment of Nylon Surfaces at Atmospheric Pressure and Their Implications in Photocatalytic Processes

César Pulgarin, Juan Kiwi

Innovative pretreatment by UVC light (185 nm) and by radio-frequency (RF) plasma at atmospheric pressure to functionalize the Nylon surface, increasing its bondability toward TiO2, is reported in this study In the case of UVC light pretreatment in air, the ...

2009

Exploring the role of post-translational modifications in regulating α-synuclein interactions by studying the effects of phosphorylation on nanobody binding

Hilal Lashuel, Juan Kiwi, Bruno Claude Daniel Fauvet, Anass Chiki

Intracellular deposits of α-synuclein in the form of Lewy bodies are major hallmarks of Parkinson’s disease (PD) and a range of related neurodegenerative disorders. Post-translational modifications (PTMs) of α-synuclein are increasingly thought to be major ...

2018

Photocatalysis/catalysis by innovative TiN and TiN-Ag surfaces inactivate bacteria under visible light

César Pulgarin, Juan Kiwi, Sami Rtimi, Rosendo Sanjines

This study presents the design, preparation, testing and characterization of TiN and TiN-Ag nanoparticulate films leading to photocatalytic and catalytic inactivation of Escherichia coli. When Ti was sputtered in N2 atmosphere, the TiN films unexpectedly r ...

Elsevier2012

Stable Ta2O5 nanotubes decorated by PbS by the SILAR method for photocatalytic dye degradation

Juan Kiwi, Sami Rtimi

Tantalum oxide Ta2O5 nanotubes (NTs) were prepared by electrochemical anodization and were decorated with lead sulfide nanoparticles PbS (NPs) by Successive Ionic Layer Adsorption and Reaction commonly known as the SILAR method. The PbS NPs/Ta2O5 NTs were ...

2023

Laser kinetic spectroscopy of the interfacial charge transfer between membrane cell walls of E. coli and TiO2

César Pulgarin, Juan Kiwi, Damien Gumy

This laser kinetics features of the electron decay of TiO2 in the presence of the Escherichia coli (E. coli) phosphatidyl-ethanolcholine (PE) and lipo-polysaccharides (LPS) cell wall components were are reported in this study. The interaction of the biomol ...

2006

Innovative photocatalyst (FeOx–TiO2): transients induced by femtosecond laser pulse leading to bacterial inactivation under visible light

César Pulgarin, Juan Kiwi, Sami Rtimi, Michaël Bensimon, Rosendo Sanjines

This study reports the photosensitizing effect/mechanism of FeOx under visible light irradiation and charge transfer to TiO2 on FeOx–TiO2 cosputtered film. The transients which were photo-induced by femtosecond laser pulses at 545 nm (25 fs) were identifie ...

RSC Publishing2015

Preparation, testing and performance of a TiO2/polyester photocatalyst for the degradation of gaseous methanol

César Pulgarin, Juan Kiwi

TiO2 modified polyester photocatalysts were prepared by immersion. drying and curing of the polyester in TiO2 containing suspensions under different experimental conditions. The structure of TiO2 layers on the polyester varied according to the time of imme ...

2010

TiO2/rough surface of woven cotton fabrics prepared by spin coating for antibacterial and self-cleaning processes

César Pulgarin, Juan Kiwi

TiO2 has been widely used in developing self-cleaning coatings on textiles. Spin coating is widely used to prepare films due to its simplicity and the ability to control the thickness and the characteristics of the deposited layers. However, it has been sp ...

2025

High power impulse magnetron sputtering (HIPIMS) and traditional pulsed sputtering (DCMSP) Ag-surfaces leading to E. coli inactivation

César Pulgarin, Juan Kiwi, Rosendo Sanjines

This study addresses the high power impulse magnetron sputtering (HIPIMS) deposition of Ag-nanoparticle films on polyester and the comparison with films deposited by direct current pulsed magnetron sputtering (DCMSP). The first evidence is presented for th ...

2012

Recent advances on sputtered films with Cu in ppm concentrations leading to an acceleration of the bacterial inactivation

Juan Kiwi, Sami Rtimi

This review focuses on the acceleration of the bactericidal and fungicidal effects by uniform, adhesive Cu-based nanocomposites on textile and thin polymer surfaces. The acceleration of the bacterial inactivation kinetics mediated by Cu, TiO2/Cu and ZrO2-T ...

ELSEVIER2020

New Evidence for Ag-Sputtered Materials Inactivating Bacteria by Surface Contact without the Release of Ag Ions: End of a Long Controversy?

Juan Kiwi, Sami Rtimi

The study provides new evidence for Ag-coated polyester (PES) mediating Escherichia colt inactivation by way of genetically engineered E. coli (without porins, from now denoted porinless bacteria). This allows the quantification of the bactericidal kinetic ...

AMER CHEMICAL SOC2020

Supported TiO2 films deposited at different energies: Implications of the surface compactness on the catalytic kinetics

César Pulgarin, Juan Kiwi, Sami Rtimi, Michaël Bensimon, Stefanos Giannakis, Rosendo Sanjines

Insight is provided in this study for the effect of the TiO2film densification/compactness on polyethy-lene (PE-TiO2) by sputtering TiO2at two very different energy levels. Uniform, adhesive low energy filmswere prepared by direct current magnetron sputter ...

Elsevier2016

New evidence for disinfection, self-cleaning and pollutant degradation mediated by GF-TiO2-Cu mats under solar/visible light in mild oxidative conditions

César Pulgarin, Juan Kiwi, Michaël Bensimon, Stefanos Giannakis, Laura Victoria Suárez Murillo

This study presents the performance of GF-mats loaded with TiO2 and Cu under solar/visible light leading to bacterial inactivation and pollutant degradation at both solid-air and solid-liquid interfaces. The GF-mats show effective water disinfection, self- ...

Elsevier2017

Oxygen Distribution of Fluorine-doped Tin Oxide Films Coated on Float Glass along Depth Before and After Heat Treatment

César Pulgarin, Juan Kiwi

Fluorine-doped tin oxide (FTO) films were deposited on float glass to create low-emissivity glass (low-E glass) by atmospheric pressure chemical vapor deposition (APCVD). Heat treatments were carried out to assess its antioxidant properties. The surface mo ...

Wiley Periodicals, Inc2013

Optimization of the solution parameters during the degradation of Orange II in a photo-reactor mediated by Fe-Nafion membranes

Juan Kiwi

The Fenton and photo-Fenton mediated degradation process of Orange II was investigated in a flow photo-reactor. The degradation was monitored as a function of the wavelength of the applied light, recirculation flow rate, amount of H2O2 and the initial conc ...

2009