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No description available.

Carbon fiber reinforced polymer (CFRP) is widely used in the industrial world due to its high strength-to-weight ratio. Aerospace manufacturers incorporate CFRP into the main structure of their flight vehicles. The extensive use of CFRP sparks the interest in efficient methods for manufacturing and repair. One of the most used repair methods is the bonded joint method, which includes different types of joints, e.g. scarf joint, step joint and single-lap joint. Scarf joint is generally selected for repair method due to its derived outcome. To improve strength of the bonded joint, the mating adherend surfaces are usually treated before being bonded. This treatment aims to enhance the mechanical interlocking and absorption properties between adhesive and adherend. Manual or electrical sanding is a standard method currently used in the industry. Recently, laser treatment is of high interest due to its potential for an automated process and consistent results. Laser treatment is usually preformed uniformly across the CFRP, regardless of the stacking sequence. This process may introduce local enhancement in some ply orientations, but also damage in other plies. This work investigates the effect of local (ply-specific) treatment on the scarf joint strength of CFRP. Effects of laser fluence (energy density) on treated ply were evaluated using surface characterization methods, viz. optical microscopy, profilometry and sessile drop technique. Finally, tensile test was performed on CFRP scarf joint. Results show that ply-specific laser treatment improves the tensile strength of CFRP scarf joint. The treatment offers localized enhancement to the surface properties and bonding strength, which results in overall tensile strength improvement.

The controlled degradation of wood surfaces with infrared light from a CO2 pulsed laser facilitated adhesion without the use of additional resins. Laser modification creates a surface phenomenon that physically and chemically alters the natural biopolymer organization of lignocellulosic materials in a way that promotes adhesion when hot pressed using typical industrial equipment. Laser optimization was determined through mechanical and microscopic observation. It was determined that a mild level of laser surface modification (scale of 30 W/mm2) resulted in the highest bond-line strength. The large spot size of the laser beam resulted in evenly modified surfaces. Surface analysis revealed that laser modification changed native wood morphology, hydrolyzed and vaporized hemicellulose, and enriched the surface with cellulose II and lignin. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FTIR) was used to analyze the bulk of the laser material. This experiment revealed a change in the hydroxyl region related to hydrogen bonding conformations between wood polymers, mainly cellulose. X-ray photoelectron spectroscopy (XPS) provided an elemental composition of the top 5 nanometers of the surface, which resulted in increased carbon-carbon/carbon-hydrogen linkages and decreased oxygen containing bonds due to laser ablation. Static acid-base contact angle analysis was conducted using three probe liquids to find the Lewis acid, Lewis base, and dispersion components of the top nanometer of surface chemistry. Contact angle analysis revealed laser modified samples had a surface free energy that remained similar to the control wood sample. In addition, the dispersion component of the surface free energy increased due to laser ablation while acid-base components were reduced. Atomic force microscopy (AFM) visually displays a reduction in surface roughness due to the laser technique. An additional set of experiments like thermal gravimetric analysis, thermal pre and post treatments, and heated ATR FTIR and XPS support findings which require more investigation into this adhesion phenomenon. / Master of Science

In this work, we demonstrate that cutting diamond crystals with a laser (532 nm wavelength, 0.5 mJ energy, 200 ns pulse duration at 15 kHz) produced a ≲20 nm thick surface layer with magnetic order at room temperature. We measured the magnetic moment of five natural and six CVD diamond crystals of different sizes, nitrogen contents and surface orientations with a SQUID magnetometer. A robust ferromagnetic response at 300 K was observed only for crystals that were cut with the laser along the (100) surface orientation. The magnetic signals were much weaker for the (110) and negligible for the (111) orientations. We attribute the magnetic order to the disordered graphite layer produced by the laser at the diamond surface. The ferromagnetic signal vanished after chemical etching or after moderate temperature annealing. The obtained results indicate that laser treatment of diamond may pave the way to create ferromagnetic spots at its surface.

Objetivo: Avaliar os efeitos da panfotocoagulação a laser (PRP) comparando com a PRP associada com injeção de 0,5 mg de ranibizumabe intravítreo (IVR) em pacientes com retinopatia diabética proliferativa (RDP) com características de alto risco. Métodos: Estudo prospectivo incluindo pacientes portadores de RDP de alto risco sem tratamento prévio, distribuídos aleatoriamente em dois grupos: grupo PRP e grupo PRPplus. Avaliações oftalmológicas padronizadas, incluindo melhor acuidade visual corrigida (MAVC), de acordo com o Early Treatment Diabetic Retinopathy Study (ETDRS), medidas da área de vazamento de fluoresceína na angiofluoresceinografia (FLA), medida da espessura do subcampo macular (ESM) na Tomografia de Coerência Óptica (OCT) foram realizadas na visita inicial e nas semanas 16 (±2), 32 (±2) e 48 (±2), além de eletrorretinograma (ERG) de campo total, realizado na visita inicial e na semana 48 (±2). Resultados: Vinte e nove de 40 pacientes (n=29) completaram as 48 semanas do estudo. Na visita inicial, a média ± erro-padrão da média (EPM) de FLA (mm2) foi de 9,0 ± 1,3 e 11,7 ± 1,3 (p=0,1502); MAVC (logMAR), 0,31 ± 0,05 e 0,27 ± 0,06 (p=0,6645) e ESM (µm), 216,3 ± 10,7 e 249,4 ± 36,1 (p=0,3925), nos grupos PRP e PRPplus, respectivamente. Foi notada significativa (p<0,05) redução na FLA em todas as visitas do estudo em ambos os grupos; porém significativamente maior no grupo PRPplus, em relação ao grupo PRP, no final da visita 48 (PRP = 2.9 ± 1.3 mm2; PRPplus = 5.8 ± 1.3 mm2; p = 0.0291). Observou-se piora na MAVC em todas as visitas após o tratamento no grupo PRP (p<0,05), enquanto que no grupo PRPplus não foram encontradas mudanças na MAVC. Aumento significativo na ESM foi observado em todas as avaliações do estudo no grupo PRP e significativa diminuição na ESM foi detectada na semana 16 do grupo PRPplus, e não foi encontrada diferença significativa, em relação à visita inicial, nas semanas 32 e 48. Quanto ao ERG, foi notada significativa diminuição na amplitude da onda-b dos bastonetes para 46 ± 5% (p<0,05) do valor da visita inicial no grupo PRP e para 64 ± 6% no grupo PRPplus. Essa regressão foi significativamente maior no grupo PRP do que no grupo PRPplus (p=0,024). Resultados similares foram observados para resposta máxima combinada (MC) da amplitude da onda-b, com redução na semana 48, comparada com a visita inicial, de 45 ± 4% no grupo PRP e 62 ± 5% no grupo PRPplus. A diminuição deste parâmetro foi significativamente maior no grupo PRP do que no grupo PRPplus (p=0,0094). A MC da amplitude da onda-a, os potenciais oscilatórios (PO) e a resposta ao flicker de 30 Hz mostraram redução estatisticamente significativa na análise intragrupos, mas sem diferenças na análise entre os grupos. Conclusão: Após a PRP foi associado IVR com maior redução na FLA na semana 48, comparado com PRP isoladamente, em olhos com RDP de alto risco, sendo que o uso adicional de IVR à PRP parece proteger contra discreta perda de acuidade visual e espessamento macular observado em olhos tratados com PRP isoladamente. Na análise do ERG, resultados sugerem que o tratamento de RDP de alto risco com PRP associado com IVR é efetivo para o controle da RDP e permite menor uso do laser, que, consequentemente, leva à perda funcional menor da retina do que o tratamento com PRP isoladamente. / Objective: To evaluate the effects of panretinal photocoagulation (PRP) compared with PRP plus intravitreal injection of 0.5 mg of ranibizumab (IVR) in patients with high-risk proliferative diabetic retinopathy (PDR). Methods: Prospective study included patients with high-risk PDR and no prior laser treatment randomly assigned to receive PRP (PRP group) or PRP plus IVR (PRPplus group). Standardized ophthalmic evaluations including best-corrected visual acuity (BCVA) measured according to the methods used in the Early Treatment Diabetic Retinopathy Study (ETDRS), fluorescein angiography to measure area of fluorescein leakage (FLA) and optical coherence tomography (OCT) for the assessment of central subfield macular thickness (CSMT), were performed at baseline and at weeks 16 (±2), 32 (±2) and 48 (±2). Eletroretinographic (ERG) was measured according to ISCEV standards at baseline and at week 48 (±2). Results: Twenty-nine of 40 patients (n = 29 eyes) completed the 48-week study follow-up period. At baseline, mean ± SE FLA (mm2) was 9.0 ± 1.3 and 11.7 ± 1.3 (p = 0.1502); BCVA (logMAR) was 0.31 ± 0.05 and 0.27 ± 0.06 (p = 0.6645); and CSMT (µm) was 216.3 ± 10.7 and 249.4 ± 36.1 (p = 0.3925), in the PRP and PRPplus groups, respectively. There was a significant (p < 0.05) FLA reduction at all study visits in both groups, with the reduction observed in the PRPplus group significantly larger than that in the PRP group at week 48 (PRP = 2.9 ± 1.3 mm2; PRPplus = 5.8 ± 1.3 mm2; p = 0.0291). Best-corrected visual acuity worsening was observed at 16, 32 and 48 weeks after treatment in the PRP group (p < 0.05), while no significant BCVA changes were observed in the PRPplus group. A significant CSMT increase was observed in the PRP group at all study visits, while a significant decrease in CSMT was observed in the PRPplus group at week 16, and no significant difference in CSMT from base- line was observed at weeks 32 and 48. ROD b-wave amplitude was significantly reduced to 46 ± 5 % (p<0.05) of baseline in the PRP group and 64±6% (p<0.05) in the PRPplus group. This reduction was significantly larger in the PRP group than in the PRPplus group (p=0.024). Similar results were observed for the dark-adapted Combined Response (CR) b-wave amplitude, with a reduction at 48 weeks compared to baseline of 45 ± 4 % in the PRP group and 62 ± 5 % in the PRPplus group; the reduction in CR b-wave amplitude was significantly larger in the PRP group than in the PRPplus group (p=0.0094). CR a-wave, oscillatory potentials, cone single flash, and 30 Hz flicker responses showed statistically significant within-group reductions, but no differences in between-group analyses. Conclusions: Intravitreal ranibizumab after PRP was associated with a larger reduction in FLA at week 48 compared with PRP alone in eyes with high-risk PDR, and the adjunctive use of IVR appears to protect against the modest visual acuity loss and macular swelling observed in eyes treated with PRP alone. In ERG analyses, the results suggest that treating high-risk PDR with PRP plus IVR is effective for PDR control, and permits the use of less extensive PRP which, in turn, induces less retinal functional loss, than treatment with PRP alone.

Objetivo: Avaliar os efeitos da panfotocoagulação a laser (PRP) comparando com a PRP associada com injeção de 0,5 mg de ranibizumabe intravítreo (IVR) em pacientes com retinopatia diabética proliferativa (RDP) com características de alto risco. Métodos: Estudo prospectivo incluindo pacientes portadores de RDP de alto risco sem tratamento prévio, distribuídos aleatoriamente em dois grupos: grupo PRP e grupo PRPplus. Avaliações oftalmológicas padronizadas, incluindo melhor acuidade visual corrigida (MAVC), de acordo com o Early Treatment Diabetic Retinopathy Study (ETDRS), medidas da área de vazamento de fluoresceína na angiofluoresceinografia (FLA), medida da espessura do subcampo macular (ESM) na Tomografia de Coerência Óptica (OCT) foram realizadas na visita inicial e nas semanas 16 (±2), 32 (±2) e 48 (±2), além de eletrorretinograma (ERG) de campo total, realizado na visita inicial e na semana 48 (±2). Resultados: Vinte e nove de 40 pacientes (n=29) completaram as 48 semanas do estudo. Na visita inicial, a média ± erro-padrão da média (EPM) de FLA (mm2) foi de 9,0 ± 1,3 e 11,7 ± 1,3 (p=0,1502); MAVC (logMAR), 0,31 ± 0,05 e 0,27 ± 0,06 (p=0,6645) e ESM (µm), 216,3 ± 10,7 e 249,4 ± 36,1 (p=0,3925), nos grupos PRP e PRPplus, respectivamente. Foi notada significativa (p<0,05) redução na FLA em todas as visitas do estudo em ambos os grupos; porém significativamente maior no grupo PRPplus, em relação ao grupo PRP, no final da visita 48 (PRP = 2.9 ± 1.3 mm2; PRPplus = 5.8 ± 1.3 mm2; p = 0.0291). Observou-se piora na MAVC em todas as visitas após o tratamento no grupo PRP (p<0,05), enquanto que no grupo PRPplus não foram encontradas mudanças na MAVC. Aumento significativo na ESM foi observado em todas as avaliações do estudo no grupo PRP e significativa diminuição na ESM foi detectada na semana 16 do grupo PRPplus, e não foi encontrada diferença significativa, em relação à visita inicial, nas semanas 32 e 48. Quanto ao ERG, foi notada significativa diminuição na amplitude da onda-b dos bastonetes para 46 ± 5% (p<0,05) do valor da visita inicial no grupo PRP e para 64 ± 6% no grupo PRPplus. Essa regressão foi significativamente maior no grupo PRP do que no grupo PRPplus (p=0,024). Resultados similares foram observados para resposta máxima combinada (MC) da amplitude da onda-b, com redução na semana 48, comparada com a visita inicial, de 45 ± 4% no grupo PRP e 62 ± 5% no grupo PRPplus. A diminuição deste parâmetro foi significativamente maior no grupo PRP do que no grupo PRPplus (p=0,0094). A MC da amplitude da onda-a, os potenciais oscilatórios (PO) e a resposta ao flicker de 30 Hz mostraram redução estatisticamente significativa na análise intragrupos, mas sem diferenças na análise entre os grupos. Conclusão: Após a PRP foi associado IVR com maior redução na FLA na semana 48, comparado com PRP isoladamente, em olhos com RDP de alto risco, sendo que o uso adicional de IVR à PRP parece proteger contra discreta perda de acuidade visual e espessamento macular observado em olhos tratados com PRP isoladamente. Na análise do ERG, resultados sugerem que o tratamento de RDP de alto risco com PRP associado com IVR é efetivo para o controle da RDP e permite menor uso do laser, que, consequentemente, leva à perda funcional menor da retina do que o tratamento com PRP isoladamente. / Objective: To evaluate the effects of panretinal photocoagulation (PRP) compared with PRP plus intravitreal injection of 0.5 mg of ranibizumab (IVR) in patients with high-risk proliferative diabetic retinopathy (PDR). Methods: Prospective study included patients with high-risk PDR and no prior laser treatment randomly assigned to receive PRP (PRP group) or PRP plus IVR (PRPplus group). Standardized ophthalmic evaluations including best-corrected visual acuity (BCVA) measured according to the methods used in the Early Treatment Diabetic Retinopathy Study (ETDRS), fluorescein angiography to measure area of fluorescein leakage (FLA) and optical coherence tomography (OCT) for the assessment of central subfield macular thickness (CSMT), were performed at baseline and at weeks 16 (±2), 32 (±2) and 48 (±2). Eletroretinographic (ERG) was measured according to ISCEV standards at baseline and at week 48 (±2). Results: Twenty-nine of 40 patients (n = 29 eyes) completed the 48-week study follow-up period. At baseline, mean ± SE FLA (mm2) was 9.0 ± 1.3 and 11.7 ± 1.3 (p = 0.1502); BCVA (logMAR) was 0.31 ± 0.05 and 0.27 ± 0.06 (p = 0.6645); and CSMT (µm) was 216.3 ± 10.7 and 249.4 ± 36.1 (p = 0.3925), in the PRP and PRPplus groups, respectively. There was a significant (p < 0.05) FLA reduction at all study visits in both groups, with the reduction observed in the PRPplus group significantly larger than that in the PRP group at week 48 (PRP = 2.9 ± 1.3 mm2; PRPplus = 5.8 ± 1.3 mm2; p = 0.0291). Best-corrected visual acuity worsening was observed at 16, 32 and 48 weeks after treatment in the PRP group (p < 0.05), while no significant BCVA changes were observed in the PRPplus group. A significant CSMT increase was observed in the PRP group at all study visits, while a significant decrease in CSMT was observed in the PRPplus group at week 16, and no significant difference in CSMT from base- line was observed at weeks 32 and 48. ROD b-wave amplitude was significantly reduced to 46 ± 5 % (p<0.05) of baseline in the PRP group and 64±6% (p<0.05) in the PRPplus group. This reduction was significantly larger in the PRP group than in the PRPplus group (p=0.024). Similar results were observed for the dark-adapted Combined Response (CR) b-wave amplitude, with a reduction at 48 weeks compared to baseline of 45 ± 4 % in the PRP group and 62 ± 5 % in the PRPplus group; the reduction in CR b-wave amplitude was significantly larger in the PRP group than in the PRPplus group (p=0.0094). CR a-wave, oscillatory potentials, cone single flash, and 30 Hz flicker responses showed statistically significant within-group reductions, but no differences in between-group analyses. Conclusions: Intravitreal ranibizumab after PRP was associated with a larger reduction in FLA at week 48 compared with PRP alone in eyes with high-risk PDR, and the adjunctive use of IVR appears to protect against the modest visual acuity loss and macular swelling observed in eyes treated with PRP alone. In ERG analyses, the results suggest that treating high-risk PDR with PRP plus IVR is effective for PDR control, and permits the use of less extensive PRP which, in turn, induces less retinal functional loss, than treatment with PRP alone.

Orientador: Robson Francisco Carvalho / Resumo: A irradiação pelo laser de baixa intensidade (LBI) tem sido utilizada como um método nãoinvasivo para promover ou acelerar a capacidade de regeneração muscular. No entanto, os mecanismos moleculares regulatórios pelos quais o LBI exerce esses efeitos, permanecem em grande parte desconhecidos. Nosso objetivo foi realizar uma análise de sequenciamento de RNA (RNA-Seq) em mioblastos C2C12 após LBI. Foram realizadas as taxas de viabilidade, migração, proliferação e os dados de RNA-Seq dos mioblastos C2C12, identificando 514 genes diferencialmente expressos após LBI. Em seguida, uma análise de ontologia genética e das vias dos genes diferencialmente expressos revelaram transcritos relacionadas ao ciclo celular, biogênese ribossômica, resposta ao estresse, migração celular, estrutura morfológica e proliferação de células musculares. Após, cruzamos nossos dados de RNA-Seq com dados de transcriptomas disponíveis em base de dados públicas, com dados de diferenciação miogênica que mostraram um total de 42 transcritos sobrepostos (mioblastos vs miotubos). Este conjunto de transcritos compartilhados mostrou que os mioblastos irradiados pelo LBI, possuem um perfil transcricional semelhante ao de miotubo, agrupando-se distante do perfil transcricional dos mioblastos. Concluíndo, revelamos pela primeira vez que LBI, induz a uma expressão de um grande conjunto de RNAm, que codificam proteínas reguladoras do ciclo celular que podem controlar a proliferação e diferenciação de mioblastos em mio... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Low-level laser irradiation (LLLT) has been used as a non-invasive method to promote or accelerate muscular regeneration capability. However, the regulatory molecular mechanisms by which LLLT exerts these effects remain largely unknown. Our goal was to perform a RNAsequencing (RNA-Seq) analysis in C2C12 myoblasts after LLLT. C2C12 myoblasts viability, migration, proliferation and RNA-Seq were performed, identifying 514 differentially expressed genes after LLLT. Next, gene ontology and pathway analysis of the differentially expressed genes revealed transcripts among categories related to cell cycle, ribosome biogenesis, response to stress, cell migration, morphological structure and muscle cell proliferation. After, we intersected our RNA-Seq data with transcriptomes publicly available myogenic differentiation data that showed a total of 42 overlapping transcripts (myoblasts vs myotube). This set of shared transcripts showed that the LLLT-myoblasts have a myotube-like profile, clustering away from the myoblast profile. In conclusion, we revealed for the first time that LLLT induces the expression a large set of mRNAs encoding for cell cycle regulatory proteins that may control myoblasts proliferation and differentiation into myotubes. Importantly, these set of mRNA revealed a myotube-like transcriptional profile and provided new insights to the understanding of the specific molecular changes underlying the effects of LLLT irradiation on skeletal muscle cells. / Doutor

Le contexte industriel de cette étude est la modification de surface de l’alliage 690(60%Ni, 30%Cr, 10%Fe) utilisé dans la fabrication de tubes de générateurs de vapeur.L’objectif de ce travail de thèse est donc de former, par traitement de fusion par laser nanopulsé, une couche de Cr2O3 étanche au relâchement du nickel. Pour maîtriser la formation decette couche, il est primordial de déterminer les paramètres opératoires influant sur lespropriétés de cette couche. L’objectif scientifique est alors d’expliquer les phénomènesintervenant pendant et après l’impulsion laser au niveau de l’extrême surface.Suite à une étude paramétrique détaillée, un traitement de fusion superficielle par laser nanopulsé a permis d’obtenir un fort rapport Cr/Ni en surface et une couche d’oxyde dense etcontinue. Afin de vérifier l’efficacité du traitement, des coupons traités ont été introduits dansune boucle simulant le milieu primaire.Des expériences et des calculs ont été mis en oeuvre pour tenter d’expliquer l’enrichissementen chrome de la surface à l’aide de ce procédé. Les résultats expliquent l’enrichissement enchrome jusqu’à la solidification du bain liquide en surface qui précède la formation du Cr2O3favorisée par la forte affinité du chrome avec l’oxygène et la grande stabilité de l’oxyde Cr2O3. / Alloy 690 (60%Ni, 30%Cr, 10%Fe) is mainly used in primary circuit pipes fornuclear power plants.The aim of this thesis is to form a Cr2O3 layer, using laser surface melting, with the objective ofcreating a chromium-rich oxide layer. In order to optimize the treatment, it was first important todetermine parameters influence on the layer oxide properties then, with the objective of adeeper understanding of mechanisms involved, to address thermo-physical phenomenaoccurring during and after the laser pulse striking the upper surface.A deep parametric study first enabled to find an optimized laser surface treatment whichproduces chromium enrichment of the upper surface and a dense and continuous oxide layer.This treatment has been applied on samples, set in a primary medium simulation loop.Experiments and calculations were carried out to provide understanding of surface chromiumenrichment by laser process. The results were shown to explain chromium enrichment until meltpool solidification occurred on the upper surface, assumingly just before chromium oxideformation. This was also promoted by a high affinity with oxygen and a higher stability of Cr2O3oxide compared with other potential oxide formation.

Ce présent travail de thèse porte sur l’étude du potentiel d’un traitement de surface par laser femtoseconde comme étape de substitution aux traitements réalisés actuellement lors de la métallisation de polymère. Pour cela, l’étude des modifications chimiques et morphologiques induites par traitement laser femtoseconde ainsi que leurs influences respectives sur les propriétés d’adhérences et de mouillabilités de la surface polypropylène sont présentées. Une revue bibliographique met en évidence la faisabilité d’une modification contrôlée de la surface du polypropylène après traitement laser femtoseconde. De plus, ces modifications engendrent une évolution démontrée des propriétés de mouillage qui peuvent répondre à certaines demandes industrielles. Après traitement laser femtoseconde, la surface traitée répond de différentes manières à la sollicitation en fonction de ses propriétés intrinsèques. Les expériences d’impacts localisés et de surfaces nous ont conduits à observer trois stades de modifications topographiques pour les conditions étudiées : un phénomène d’incubation, d’accumulation et d’ablation. Ce dernier a fait l’objet d’une étude plus approfondie. De manière générale, on observe deux régimes d’ablation linéaires pour l’ensemble des densités de puissance étudiées lorsque l’on étudie la profondeur d’ablation en fonction du nombre d’impulsion et le volume d’ablation en fonction de la densité de puissance cumulée. Enfin, nous montrons que les liaisons présentes en surface après traitement sont dépendantes de deux facteurs ; la densité de puissance cumulée utilisée et l’environnement de travail. Sachant que les modifications topographiques obtenues sont de types multi-échelles, les résultats ont été analysés sur la base des modèles de Wenzel (1936) et de Cassie-Baxter (1944) relatifs à la théorie du mouillage de surfaces rugueuses. Les résultats expérimentaux et leurs corrélations avec les paramètres de rugosités 3D calculés à différentes échelles ont été traités par une analyse statistique. On observe alors un comportement mixte avec un contact intime de la goutte sur les sommets des aspérités (modèle de Wenzel) et un contact hétérogène (airpolypropylène) à une échelle mésoscopique (état « fakir » décrit par le modèle de Cassie-Baxter). Toutefois, la situation où la goute repose sur le sommet des structures (CB) n’est pas toujours stable. Nous avons étudié la transition de l’état CB à l’état W par des expériences d’évaporation. On observe que cette transition est fortement dépendante de la chimie de surface dont la contribution est prépondérante sur les propriétés d’adhérence métal/PP. En contrôlant cette propriété, il est alors possible de répondre à une problématique industrielle de galvanoplastie (adhérence augmenté par le traitement laser) ou d’électroformage (adhérence faible permettant une réplication de bonne qualité des motifs). / This work presents the potential of a femtosecond laser surface treatment as an alternative step of pretreatments during the metallization of polymer. To do this, the study of chemical and morphological modification induced by femtosecond laser treatment and their respective influences on the properties of adhesion and wettability of polypropylene surface are presented. A literature review highlights the feasibility of a controlled surface modification after femtosecond laser treatment of polypropylene (PP). In addition, it is known that these modifications changes the wetting properties and can be used to meet industrial applications development. After femtosecond laser treatment, the treated surface responds to the solicitation with different morphological comportment according to its intrinsic properties. Experiences of localized impacts and surfaces us to observe three stages of topographic changes to the conditions studied: an incubation phenomenon of accumulation and ablation. The ablation phenomenon is further study. Generally, two linear ablation regime is observed for all power densities examined when considering the depth of ablation as a function of the pulse number and the ablation volume according to the accumulated power density. Finally, we show that the bonds present on the surface after treatment are dependent on two factors: the accumulated power density used and the working environment. Knowing that topographic obtained is multi-scales, the results were analyzed on the basis of models Wenzel (W)(1936) and Cassie–Baxter (CB) (1944) which explain the theory of wetting of rough surfaces. The experimental results and their correlations with 3D roughness parameters calculated at different scales were treated by statistical analysis. We observe a mixed model behavior with intimate contact of the drop on the tops of the asperities (Wenzel model) and a heterogeneous contact (air - PP) in a mesoscopic scale (state " fakir " described by the Cassie -Baxter model). However, this situation where the drop sits on the top of asperities (CB) is not always the most stable. We have studied the transition between the CB state and the W state by evaporation experiments. It is observed that this transition is strongly dependent on the surface chemistry whose contribution is much greater than the adhesion properties metal / PP. If controlling this property, it is possible to obtain two industrial applications: electroplating (increased adhesion by laser treatment) or electroforming (low adherence to replicate the topography).