Poly(lactic acid)/TiO₂ nanocomposites as alternative biocidal and antifungal materials.
Poly(lactic acid) (PLA) composites with titanium oxide (TiO2) ~10-nm nanoparticles were produced by the melting process and their main properties were evaluated. The nanoparticles are homogeneously dispersed in the matrix with a low degree of agglomeration, as seen by transmission electron microscopy (TEM). The crystallinity temperature increased ~12% when 5 wt.% of TiO2 was added, showing that the nanoparticles acted as nucleating agents this trend was confirmed by optical images. The elastic modulus increased ~54% compared to neat PLA at 5 wt.% of nanoparticles. Despite these improvements, PLA/TiO2 nanocomposites showed lower shear viscosity than neat PLA, possibly reflecting degradation of the polymer due to the particles. Regarding biocidal properties, after 2h of contact the PLA/TiO2 composites with 8 wt.% TiO2 showed a reduction of Escherichia coli colonies of ~82% under no UVA irradiation compared to pure PLA. This biocidal characteristic can be increased under UVA irradiation, with nanocomposites containing 8 wt.% TiO2 killing 94% of the bacteria. The PLA/TiO2 nanocomposites with 8 wt.% were also 99.99% effective against Aspergillus fumigatus under the UVA irradiation.
POLCA, Departamento de Ingeniería Mecánica, Química y Diseño Industrial, Escuela Técnica Superior de Ingeniería y Diseño Industrial, Universidad Politécnica de Madrid, Ronda de Valencia 3, Madrid, Spain.
Carmen
C
Fonseca
POLCA, Departamento de Ingeniería Mecánica, Química y Diseño Industrial, Escuela Técnica Superior de Ingeniería y Diseño Industrial, Universidad Politécnica de Madrid, Ronda de Valencia 3, Madrid, Spain.
Almudena
A
Ochoa
Programa de Microbiología y Micología. ICBM-Facultad de Medicina Universidad de Chile, Dirección, Avenida Independencia 1027, Comuna Independencia, Santiago, Chile.
Maria Teresa
MT
Ulloa
Programa de Microbiología y Micología. ICBM-Facultad de Medicina Universidad de Chile, Dirección, Avenida Independencia 1027, Comuna Independencia, Santiago, Chile.
Eduardo
E
Alvarez
Grupo Polímeros, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Casilla 40, Correo 33, Santiago, Chile.
Daniel
D
Canales
Grupo Polímeros, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Casilla 40, Correo 33, Santiago, Chile. Electronic address: paula.zapata@usach.cl.
Paula A
PA
Zapata
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D001232:Aspergillus fumigatus / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D019344:Lactic Acid / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000008:administration & dosage / Q000737:chemistry; D053769:Nanocapsules / Q000008:administration & dosage / Q000737:chemistry / Q000648:ultrastructure; D053761:Nanocomposites / Q000008:administration & dosage / Q000737:chemistry; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D053769:Nanocapsules; D011091:Polyesters; D011108:Polymers; C009495:titanium dioxide; D019344:Lactic Acid; C033616:poly(lactide); D014025:Titanium
Mechanical properties; Nano particles; Nanocomposites; Polymer matrix composites (PMCs); Thermal properties