DEVELOPING HIERARCHICALLY STRUCTURED SUPER-REPELLENT COATINGS FOR THE REDUCED ADHESION OF BIOLOGICAL CONTAMINATES
Notice bibliographique
Résumé
Recently, the rise and appearance of antibiotic resistant pathogenic bacteria, and pathogenic viruses have resulted in significant economic and societal repercussions. The spread of pathogens has led to increases in the prevalence of infections acquired from contaminated surface, especially within healthcare environments. In response to these issues, many new technologies have been developed to address the spread of these pathogens. Repellent and antipathogenic materials have been developed to reduce the levels of contamination seen on surfaces and the ability for these surfaces to transmit pathogens. In this thesis, we developed pathogen-repellent surfaces, which significantly reduce biofouling on their surface by reducing bacterial adhesion due to their omniphobic properties and deactivating the adhered pathogens via the production or Radical Oxygen Specie (ROS). Superhydrophobic wetting states have been shown to reduce the adhesion of biological contaminants and prevent biofouling at the surface. However, the performance of these repellent properties is dependent on the stability of the wetting states. Hierarchical structured surfaces with topography in both the micro- and nano-scale increase the stability of these wetting states when compared to structures at each individual length scale, and thus show potential in further increasing the repellency of surfaces in response to biological contaminants. To create a superhydrophobic and repellent surface with a hierarchically structured surface, we developed an all solution-based technique for depositing nanoparticle (NP) films. This method utilized self-assembled monolayers of ((3-Aminopropyl)triethoxysilane (APTES). The positive charge of the uniform amine monolayer was able to then ionically bond to negatively charged gold nanoparticles (AuNP) and silica nanoparticles (SiNP). This was combined with pre-strained polymer substrates which allowed for the formation of a wrinkled microstructure when shrunk, resulting in nanotextured microscale wrinkles. These Structures were then paired with a self-assembled coating of Fluorosilane (FS), which greatly reduced the surface energy of the surface and formed robust superhydrophobic states. To characterize the resistance of the surfaces to biofouling, we explored the interaction of the surface to blood staining and thrombosis under both static and dynamic conditions and found a greater than 90% reduction in contamination for all cases. To quantify the adhesion of pathogens to the repellant surfaces, a touch transfer assay was designed, which simulated the transmission from contaminated human hands to sterile surfaces. Two viral pathogens, Herpes Simplex Virus 2 (HSV2) and Human Coronavirus 229E (HuCoV), were tested under single and multiple contamination events, and the surfaces were imaged using SEM to confirm the levels of viral contamination, and showed a reduction greater than 4-log to the adhesion of both viruses. Bacterial contamination was tested for multiple different bacterial pathogens: Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), Pseudomonas aeruginosa (P. aeruginosa) and Methicillin-Resistance Staphylococcus aureus (MRSA)). The omniphobic surface here showed a reduction of all bacterial pathogen species of roughly 2.77-log, both individually and in combination. To further reduce the contamination of the surface with pathogens, the repellant surface structures were modified with photoactive TiO2 nanoparticles, to introduce antipathogenic properties into the films. These surfaces were able to reduce the initial adhesion of bacteria pathogens by 2.77-log while also being able to decrease surface contamination by another 2.5-log after exposure to ultra-violet (UV) light.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».