Procedure for the preparation and defense of the research plan

Doctoral candidates must submit a research plan, which will be included in their doctoral student activity report, before the end of the first year. The plan may be improved over the course of the doctoral degree. It must be endorsed by the tutor and the supervisor, and it must include the method that is to be followed and the aims of the research.

At least one of these annual assessments will include a public presentation and defence of the research plan and work done before a committee composed of three doctoral degree holders, which will be conducted in the manner determined by each academic committee. The examination committee awards a Pass or Fail mark. A Pass mark is a prerequisite for continuing on the doctoral programme. Doctoral candidates awarded a Fail mark must submit a new research plan for assessment by the academic committee of the doctoral programme within six months.

The committee assesses the research plan every year, in addition to all of the other activities in the doctoral student activity report. Doctoral candidates who are awarded two consecutive Fail marks for the research plan will be obliged to definitely withdraw from the programme.

If they change the subject of their thesis, they must submit a new research plan.

Formation activities

Activity: Preparation and initial defence of research plan.
Hours: 4.
Type: compulsory.

Activity: Courses, lectures and seminars given by professors and visiting researchers.
Hours: 12.
Type: optional.

Activity: Specific courses and workshops for training in scientific techniques related to research in the field of polymers and biopolymers.
Hours: 15.
Type: optional.

Activity: Specific research group seminars.
Hours: 15.
Type: compulsory.

Activity: Mobility and conferences.
Hours: 60.
Type: optional.

Activity: Publications.
Hours: 100.
Type: optional.

Activity: Research stays.
Hours: 480.
Type: optional.

Activity: Cross-disciplinary activities.
Hours: 15.
Type: compulsory.

Activity: Cross-disciplinary activities.
Hours: 30.
Type: optional.

Procedure for assignment of tutor and thesis director

The academic committee of the doctoral programme assigns a thesis supervisor to each doctoral candidate when they are admitted or enrol for the first time, taking account of the thesis supervision commitment referred to in the admission decision.

The thesis supervisor will ensure that training activities carried out by the doctoral candidate are coherent and suitable, and that the topic of the candidate’s doctoral thesis will have an impact and make a novel contribution to knowledge in the relevant field. The thesis supervisor will also guide the doctoral candidate in planning the thesis and, if necessary, tailoring it to any other projects or activities undertaken. The thesis supervisor will generally be a UPC professor or researcher who holds a doctoral degree and has documented research experience. This includes PhD-holding staff at associated schools (as determined by the Governing Council) and UPC-affiliated research institutes (in accordance with corresponding collaboration and affiliation agreements). When thesis supervisors are UPC staff members, they also act as the doctoral candidate’s tutor.

PhD holders who do not meet these criteria (as a result of their contractual relationship or the nature of the institution to which they are attached) must be approved by the UPC Doctoral School's Standing Committee in order to participate in a doctoral programme as researchers with documented research experience.

The academic committee of the doctoral programme may approve the appointment of a PhD-holding expert who is not a UPC staff member as a candidate’s thesis supervisor. In such cases, the prior authorisation of the UPC Doctoral School's Standing Committee is required. A UPC staff member who holds a doctoral degree and has documented research experience must also be proposed to act as a co-supervisor, or as the doctoral candidate’s tutor if one has not been assigned.

A thesis supervisor may step down from this role if there are justified reasons (recognised as valid by the committee) for doing so. If this occurs, the academic committee of the doctoral programme will assign the doctoral candidate a new thesis supervisor.

Provided there are justified reasons for doing so, and after hearing any relevant input from the doctoral candidate, the academic committee of the doctoral programme may assign a new thesis supervisor at any time during the period of doctoral study.

If there are academic reasons for doing so (an interdisciplinary topic, joint or international programmes, etc.) and the academic committee of the programme gives its approval, an additional thesis supervisor may be assigned. Supervisors and co-supervisors have the same responsibilities and academic recognition.

The maximum number of supervisors of a doctoral thesis is two: a supervisor and a co-supervisor.

For theses carried out under a cotutelle agreement or as part of an Industrial Doctorate, if necessary and if the agreement foresees it this maximum number of supervisors may not apply. This notwithstanding, the maximum number of supervisors belonging to the UPC is two.

More information at the PhD theses section

Permanence

The academic committee of the programme may authorise an extension of up to one year for full-time doctoral candidates who have not applied to deposit their thesis by the end of the three-year period of study, in the terms outlined in the Academic Regulations for Doctoral Studies of the Universitat Politècnica de Catalunya. In the case of part-time candidates, an extension of two years may be authorised. In both cases, in exceptional circumstances a further one-year extension may be granted by the Doctoral School's Standing Committee, upon the submission of a reasoned application by the academic committee of the doctoral programme.

A doctoral candidate may be dismissed from a doctoral programme for the following reasons:

• The doctoral candidate submitting a justified application to withdraw from the programme.
• The maximum period of study and of extensions thereof ending.
• The doctoral candidate not having enrolled every academic year (unless he or she has been authorised to temporarily withdraw).
• The doctoral candidate failing two consecutive assessments.
• The doctoral candidate having disciplinary proceedings filed against him or her that rule that he or she must be dismissed from the UPC.

Dismissal from the programme implies that doctoral candidates cannot continue studying at the UPC and the closing of their academic record. This notwithstanding, they may apply to the academic committee of the programme for readmission and the committee must reevaluate them in accordance with the criteria established in the regulations.

International Mention

The doctoral degree certificate may include International Doctorate mention. In this case, the doctoral candidate must meet the following requirements:

a) During the period of study leading to the award of the doctoral degree, the doctoral candidate must have spent at least three months at a respected higher education institution or research centre outside Spain to complete courses or do research work. The stays and activities carried out must be endorsed by the thesis supervisor and authorised by the academic committee of the programme. The candidate must provide a certifying document issued by the person responsible for the research group of the body or bodies where the stay or activity was completed. This information will be added to the doctoral student’s activity report.
b) Part of the thesis (at least the summary and conclusions) must be written and presented in one of the languages commonly used for science communication in the relevant field of knowledge, which must not be an official language of Spain. This rule does not apply to stays and reports in Spanish or to experts from Spanish-speaking countries.
c) At least two PhD-holding experts belonging to a higher education institution or research centre outside Spain must have issued officially certified reports on the thesis.
d) The thesis examination committee must have included at least one PhD-holding expert from a higher education or research institution outside Spain who was not responsible for the candidate’s stay abroad (point a) above).
e) The thesis defence must have taken place on UPC premises or, in the case of joint programmes, at the location specified in the collaboration agreement.

List of authorized thesis for defense

Last update: 24/09/2022 04:45:16.

List of lodged theses

• HODÁSOVÁ, LUDMILA: Polymer-zirconia based ceramic composites produced by 3D-printing
  
  Author: HODÁSOVÁ, LUDMILA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Normal
  Deposit date: 21/09/2022
  Reading date: pending
  Reading time: pending
  Reading place: pending
  Thesis director: FARGAS RIBAS, GEMMA | ARMELIN DIGGROC, ELAINE APARECIDA
  Committee:
       PRESIDENT: FERREIRA MORGADO, JORGE MANUEL
       SECRETARI: JIMENEZ PIQUÉ, EMILIO
       VOCAL: BRAVO LARA, FERNANDO
  Thesis abstract: Zirconia ceramic is widely used in numerous fields, such as electronics, machinery, and biomedical applications, due to its excellent properties as chemical resistance, thermal stability, electrical resistance, toughness, hardness, but also inertness and g biocompatibility. The 3D-printing technology has opened new doors for possible applications of zirconia and also allows for higher complexity of the shapes and structures, even for specimens with designed porosity, which would be until now unimaginable with traditional manufacturing methods like gel casting or cold isostatic pressing. The biocompatibility, inertness, and excellent aesthetic aspects of this ceramic make it also a preferred material for biomedical applications, more specifically in dentistry.However, application in the biomedical field has had some shortcomings, where the high hardness and brittleness of the material could cause discomfort or excessive wear. One of the aims of this thesis was to develop a new hybrid material that would complement the above-mentioned properties of zirconia and at the same time try to mimic the mechanical properties and biocompatibility of natural teeth using a combination of zirconia and acrylate polymer materials, while using additive manufacturing. The first part was focused on the development and manufacturing of such material. The idea of polymer-infiltrated ceramic networks (PICN), where a porous sintered ceramic structure is interpenetrated with a polymer matrix, was followed. The innovation of this technology was based on the 3D-printing of ceramic zirconia (3Y-TZP) scaffolds with designed porosity. After the optimization of the printing process, the 50% zirconia infill was chosen as the most appropriate porosity of the scaffold that was subsequently infiltrated with bisphenol A glycerolate dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) copolymer. After the successful manufacturing of 3D-printed PICN and the proper infiltration of the copolymer, the physical-chemistry properties of the new material were characterized, as well as its mechanical properties. The bacterial adhesion was evaluated against Gram-negative Escherichia coli and Gram-positive Streptococcus salivarius bacteria lines, revealing, that although such samples do not have antimicrobial properties, they do not promote excessive bacterial growth either. Regarding biocompatibility, the cell assay using human osteoblasts (MG-63) was carried out showing good cell viability.To improve the antimicrobial properties of manufactured PICN, the surface was modified with the adhesion of silver nanoparticles, which were embedded in an enzymatically modified phenolated lignin matrix (Ag@PL NPs), obtained from renewable resources, to avoid metal particle oxidation. The functionalization of the surface of the hybrid material with such Ag NPs allowed the reduction of bacterial growth by 90% on the modified surface. The last part of this thesis focused on the improvement of osseointegration of zirconia surface in vitro. Although it is an inert material, surface modification is required to avoid possible failures of zirconia once implanted in vivo. A polydopamine methacrylate copolymer, which has proved antibiofilm formation properties, was applied to the surface of zirconia. Characterization of the surfaces has proven good viability of theMG-63 cell line and also a great adhesion of the polymeric nanofilm, produced by cold plasma to the surface of zirconia discs. Overall, this thesis describes the 3D printing of PICN structures, which have a macroporous structure for the correct infiltration of the copolymer. The synergy and good adhesion between these materials have given rise to a prototype whose mechanical properties simulate those for natural teeth
  

Last update: 24/09/2022 04:30:26.

List of defended theses by year

• BONAMIGO MOREIRA, VITOR: Zirconium oxide conversion coating and biobased organic coatings for aluminum protection
  
  Author: BONAMIGO MOREIRA, VITOR
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode:
  Reading date: 13/01/2022
  Thesis director: ARMELIN DIGGROC, ELAINE APARECIDA | MENEGUZZI, ALVARO
  

  Committee:
       PRESIDENT: KLEIJ, ARJAN WILLEM
       SECRETARI: PÉREZ MADRIGAL, MARIA DEL MAR
       VOCAL: SANCHOTENE SILVA, RODRIGO
       VOCAL: MURESAN, LIANA MARIA
       VOCAL: MOHEDANO SÁNCHEZ, MARTA
  Thesis abstract: During the past century the way humans relate to the environment has undergone important changes, and currently it is a global consensus that our well-being should not be achieved at the expense of enlarging our footprint in the planet. The metal finishing industry is notan exception to this trend. Thus, there is the urgency to replace surface treatments, such as chromate conversion coatings (CCC) or phosphating, to more sustainable technologies; as well as the need ofreducing the use of petroleum derivativas in the formulation of raw materiaIs for coatings and adhesivas indus tries. A promising substitute for CCC are the zirconium oxide based conversion coatings (ZrCC), which have been under continuous devalopment for nearly 30 years, resulting in a powerful tool for metal passivation with lower environmental impact than CCC. In this work, the electro-assisted deposition (EAD) technique was used to improve the ZrCC's covering properties on aluminum substrates, bystimulating electrochemically the coating formation, in a process that would typically be carried out relying exclusively in surface spontaneous reactions. On the other hand, this necessityof covering such passivation layer with organic coatings, that actas long-term barrier protection against corrosion, is another usual industrial process. Nevertheless, the constant generation of plastic waste has led to the need of searching for more sustainable, bio-degradable and/or recyclable polym ers to replace the essentially synthetic ones. In this way, the present thes is reports the production, characterization andapplication of thermoset epoxy polymers, containing a bio-based epoxy prepolymer deri\ed from limonene (PLCO) and industrial hardeners. For that, these results were compared to those of the traditional epoxy prepolymer diglycidyl ether of bisphenol A(DGEBA). The results indicate that PLCO has sorne enhanced properties in comparison to the synthetic epoxy polymer dueto its chemical structure (a polymer with cyclic limonene units, carbonate groups and oxyrane rings) and to its optimal molecular weight. The ZrCC layer is stable and adherent. Once this !ayer is combined with the epoxy derived from limonene, it originates a dual !ayer with protectiva properties against the corros ion of aluminum, whilst the new thermoset polymer could be also used as a solvant-based adhesiva for this same substrate thanks to its good adherence and mechanical properties. Therefore, this work approaches both, the synthesis aspects ofthose new coatings anda complete characterization and application of ali ofthe studied systems.
  

• ENSHAEI, HAMIDREZA: Biomedical Applications of Hybrid Polymer-Based materials
  
  Author: ENSHAEI, HAMIDREZA
  Thesis link: http://hdl.handle.net/10803/675187
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Temporary seizure
  Reading date: 29/04/2022
  Thesis director: ALEMAN LLANSO, CARLOS ENRIQUE | SAPERAS PLANA, NURIA
  

  Committee:
       PRESIDENT: ARMELIN DIGGROC, ELAINE APARECIDA
       SECRETARI: LANZALACO, SONIA
       VOCAL: RAMÓN AZCÓN, JAVIER
       VOCAL: MATEOS TIMONEDA, MIGUEL ÁNGEL
       VOCAL: MACOR, LORENA PAOLA
  Thesis abstract: Polymers have been widely used in biomedical applications for drug delivery purposes in the last decades. However, ordinary long­ term drug delivery systems are sometimes associated with undesired side effects if the concentration of the released drug is higher than needed. Therefore scientists look for new techniques to enhance the efficiency and safety of the release by controlling the release time. ra_teand accuracy in targeting specific tissues or cells to spare the rest of the body from side effects. In this thesis. several polymeric platforms (microfibers, hydrogels, nanoparticles, nanomembranes) and their combinations have been used to modulate and control the release of different kinds of drugs.Five different platforms have been obtained. They are described in the results section of the thesis (chapter 3):1) In section 3.1, an electrically triggered release system is presented. Specifically, the release of the antibiotic chloramphenicol (CAM) from conducting polymer nanoparticles made of poly(3,4-ethylenedioxythiophene (PEDOT) has been studied and characterized. In addition, the designed platform allows for in situ monitoring of bacteria! growth inhibition through the electrochemical detection of 13-nicotinamide adenine dinucleotide (NADH).2) A pharmacological chaperorie (pyrimethamine, PYR) has been also encapsulated in PEDOT nanoparticles (section 3.2). Release experiments carried out with and without electrical stimuli demonstrate that release can be increased up to ~50% when sustained CV stimulation is applied for 30 min.3) Section 3.3 describes a controlled release device consisting of a polypeptide hydrogel (Poly(y-glutamic acid. PGGA) loaded with a small hydrophobic drug (curcumin. CUR) which was previously encapsulated in PEDOT nanoparticles. This platform allows to tune CUR release when applying an electrical stimulus.4) In the next section (3.4), the pharmacological chaperone ambroxol hydrochloride (AH) is loaded in polymeric electrospun microfibers of poly(y-caprolactone (PCL). In order to regulate the release, electrospun microfibers have been coated with additional PCL layers using dip-coating or spin-coating. AH functionality was verified with a thermal denaturation assay utilizing GCase. demonstrating that the electrospinning procedure did not affect the functionality of the drug.5) Finally, section 3.5 reports drug release from a complex platform consisting of two spin-coated layers of PGGA hydrogel, loaded with PEDOT microparticles and separated by an electrospun layer of PCL microfibers. Poly(hydroxymethyl-3,4- ethylenedioxythiophene) (PHMeDOT) was polymerized through the whole three-layered system while forming a dense network of electrical conduction paths. The platform has been loaded with levofloxacin (LVX) before performing the release experiment. Although the release of LVX is fast, this device allows for real-time electrochemical monitoring of the remaining antibiotic inside the platform.Taken together, the studies presented in this thesis provide an overview of new hybrid polymeric platforms that allow to optimize and control drug release while, in sorne cases, achieving additional functionalities
  

• IVANOVA, ALEKSANDRA ASENOVA: Nanomaterials for controlling bacterial pathogens and resistance occurrence
  
  Author: IVANOVA, ALEKSANDRA ASENOVA
  Thesis link: http://hdl.handle.net/10803/673983
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Article-based thesis
  Reading date: 11/03/2022
  Thesis director: TZANOV, TZANKO
  

  Committee:
       PRESIDENT: PASHKULEVA, IVA HRISTOVA
       SECRETARI: GARRIGA SOLE, PERE
       VOCAL: ZILLE, ANDREA
  Thesis abstract: lnfectious diseases are the leading cause of death worldwide while the constantly raising antimicrobial resistance (AMR) is a major concern for the public health. During the infection establishment bacteria! pathogens communicate via expression of signaling molecules, controlled through a phenomenon called quorum sensing (QS). As a result of this, bacteria produce virulence factors and form resistant biofilms on living and non-living surfaces causing persistent infections. The infection complexity, especially in chronic diseases, requires the use of broad-spectrum antibiotics responsive for the appearance and the spread of drug resistant species. lnfections caused by antibiotic-resistant pathogens are associated with high morbidity, mortality, and huge economic burden. Unlike the decrease over the past three decades of the number of novel marketed antimicrobial drugs, the number of antibiotic resistant bacteria! strains steadily increases. Thus, there is an urgent need for development of alternative strategies to manage difficult-to-treat infections. This thesis aims at the engineering of advanced nano-enabled materials and nanostructured coatings for controlling bacteria! pathogenesis and resistance occurrence. To achieve this, biopolymers, antibiofilm and anti-infective enzymes. and inorganic compounds were nano-hybridized as altemative modalities to the conventional antibiotics. The nanoform was able to provide enhanced interaction with bacteria! cell membranes and easier penetration into biofilms, increasing the antimicrobial efficacy at lower dosages, while preventing from development of antimicrobial resistance. Additionally, specific targeting moieties increased the nanomaterial's interaction with the pathogens, avoiding the drug resistance appearance and cytotoxicity.The first part ofthe thesis describes the functionalization of biologically inert nanoparticles (NPs) with membrane disturbing antimicrobial aminocellulose (AM) and biocompatible hyaluronic acid (HA) in an Lbl fashion for elimination of medically relevant pathogens. The generated nanoentities demonstrated high potential to inhibit the biofilm formation, without affecting the human cell viability.Further, the Lbl technique was applied to decorate antimicrobial, but potentially toxic silver (Ag) nano-templates with biocompatible AM and quorum quenching (QQ) acylase in order to obtain safe antibacterial and antibiofilm nanomaterials. The deposition of acylase and AM on the Ag core interfered with the QS signaling and bacteria! pathogenesis, and enhanced the NPs interaction with the bacteria! membrane. The integration of a triple mechanisms of action in the hybrid nanoentities resulted in complete bacteria and biofilm eradication and improved biocompatibility ofthe AgNPs.The thesís also describes the development of targeted nanocapsules (NCs) for selective elimination of Staphylococcus aureus. Herein, self-assembling nanoencapsulation technology using the biocompatible and biodegradable proteín zein was applied for the generation of zein NCs loaded with bactericida! oregano essential oil (EO). An antibody specifically targeting S. aureus was covalently grafted on the NCs surface. The obtained targeted NCs demonstrated antibacterial selectivity in a mixed bacteria! inoculum, and the treatment efficacy was validated in an in vitro coculture model of bacteria and mammalian cells.Finally, high intensity ultrasonochemistry (US) process was employed for engineering of durable antibacterial/antibiofilm coating on urinary catheters. The simultaneous deposition of zinc oxide (ZnO) NPs anda matrix-degrading amylase enzyme improved the NPs adhesion on the silicone material, and prevented its bacteria! colonization and biofilm formation in vitro. The hybrid nanostructured coating delayed the occurrence of early onset urinary tract infections (UTls) and showed excellent biosafety in an in vivo animal model.
  

• LACRUZ CRUZ, AMADO: ECO-DWOR: ECOlogical finishing agents for Durable Water&Oil-Repellent textiles with advanced functionalities
  
  Author: LACRUZ CRUZ, AMADO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Article-based thesis
  Reading date: 18/07/2022
  Thesis director: MARTINEZ DE ILARDUYA SAEZ DE ASTEASU, DOMINGO
  

  Committee:
       PRESIDENT: LEIZA RECONDO, JOSÉ RAMÓN
       SECRETARI: BOU SERRA, JORGE
       VOCAL: SARDON MUGURUZA, HARITZ
  Thesis abstract: Fluorinated chemicals, commonly known as per- and polyfluoroalkyt substances (PFASs), are widely used to obtain water-, oil- and stain-repellent texUles. The constant development and optimization of fluorochemicals for textile applications initiated more than five decades ago has resulted in a veryefficient DWOR-technology and texUles with exceptional hydro­ and oleo-phobic properties (DWOR acronym stands for Durable Water and Oil Repellen!). However, PFASs' high mobility, persistence and harmful health effects, has been proved by numerous scientific studies and, therefore, regulation and phase-out of severa! PFASs is being implemented bygovernm ents. At the present time the textile industry lacks suitable alternatives to fluorochemicals with comparable material characteristics.The main goal ofthis work is to design fluorine-free textile finishing agents based on sustainable polymers with low surface-tension functional groups in combination with (nano)materiaIs to confer water- and oil-repellencyto textiles as well as advanced multifunctionalities.Therefore, synergies of new available bio-based building-blocks, polymer synthesis and (nano)materiaIs have been explored to develop new finishing agents able to provide water and oil repellence to fabrics, without using fluorine-containing chemicals.In this work two different chemistries to confer water- and oil-repellence to textiles have been studied. In research line 1, biobased polyurethane-ureas have been developed. Obtained waterborne polyurethane-urea dispersions (WPUD) show good mechanical and thermal properties and therefore were chosen to be coated onto fabrics byknife-coating. In this way we were able to coat one side ofthe fabrics with a continuous polyurethane-urea film, capable of drastically reducing the permeability of the textiles to water and thus conferring remarkable hydrostatic pressure values to the treated fabrics.Therefore, ease offilming ofthe obtained WPUD make them good candidates to substitute PTFE inner membranes in technical fabrics. In research line 2, new fluorine-free waterborne (co)polymethacrytates have been developed. These polymethacrytates offer excellent performance when applied to fabric bythe padding method, i.e., by total immersion ofthe fabric in the finishing liquor, squeezing at controlled speed and pressure, and subsequent drying and curing. Unlike research line 1, here the coatings obtained do not significantly increase the stiffness ofthe fabrics nor significantly reduce their air permeability. This is dueto the fact that the polymethacrytate creates a thin coating on the surface of each individual libre, giving rise to "jacketed libres" instead a continuous film on one ofthe fabric's faces. Thanks to this, highlyhydrophobic breathable fabrics with reasonablygood oleophobic properties againstfattytriglycerides have been achieved. Therefore, these polymethacrytates are good candidates to substitute side-chain perfluorinated polymers in fabric's outer !ayer by more sustainable fluorine-free alternatives. lt is important to highlight that ali the developments reported in this work are stable waterborne formulations able to be applied by standard procedures and facilities in large-scale texUle production, thus reducing its entry barrier to textile finishing industry. Finally, it is worth emphasizing the complementarity of the two developed lines of research, providing the textile sector with an open window to valid, sustainable and fluorine-free solutions to achieve high-performance DWOR finishes
  

• MARTÍNEZ CUTILLAS, ALFREDO: Poly(lactic acid) blends and copolyesters with advanced properties for biomedical applications
  
  Author: MARTÍNEZ CUTILLAS, ALFREDO
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Confidentiality
  Reading date: 13/06/2022
  Thesis director: MARTINEZ DE ILARDUYA SAEZ DE ASTEASU, DOMINGO | OH, SEJIN
  

  Committee:
       PRESIDENT: GARCÍA MARTÍN, MARÍA DE GRACIA
       SECRETARI: GARCIA ALVAREZ, MONTSERRAT
       VOCAL: ETXEBERRIA LIZARRAGA, AGUSTÍN
  Thesis abstract: Poly(lactic acid) (PLA) is a biobased, biodegradable and biocompatible polymer. Because of that, it is a polymer that generates a great interest in the research and development of new advanced materials. Among the current cutting-edge technologies, PLA is particularly a great candidate for the preparation of biomedical devices such as temporary implants for tissue regeneration. Nevertheless, neat PLA solutions cannot fulfil the requirements of a temporary implant, thus it has to be modified. That was the main purpose of this Thesis. Study how different modifications influenced PLA degradation rate, mechanical properties or cell affinity. With that aim, PLA-based blends and copolymers were prepared. All of them were extensively characterized in their more relevant physicochemical properties. Finally, the best candidates were selected to prepare functionalized scaffolds for their in vitro evaluation.In the first part of the Thesis is reported the synthesis of PLLA by ring-opening polymerization (ROP) of L-lactide under different temperatures, catalyst concentration and initiator conditions. Once the optimal reaction conditions were determined, a series of PLAs were synthetized using different concentrations of L-lactide and D-lactide isomers. These PLAs were useful to study the influence of stereoregularity on the thermal properties, the mechanical properties and the hydrolytic degradation rate of film samples. That evaluation brought out the brittle fracture of all the PLAs and the faster degradation of those heterotactic PLAs.To improve the mechanical properties of PLA, a series of triblock copolymers with A-B-A structure and varied composition of A and B were synthetized, being A referred to PLA blocks and B to polymacrolactones blocks. The triblock copolymers weresynthetized in two steps. In the first one polymacrolactones were synthesized by enzymatic ROP of unsaturated macrolactones such as globalide (Gl) and 6-¿ hexadecenlactone (6HDL) using 1,4-butanediol as initiator. Then, polyglobalide (PGl) and poly(6-¿-hexadecenlactone) (P6HDL) were used as initiators in the ROP of lactide. The triblock structure of the copolymers was validated by the different characterization techniques employed. Moreover, a wide range of mechanical properties was achieved in dependence of A and B blocks composition.As an alternative to triblock copolymers, a series of PLLA and PGl blends were prepared by melt-extrusion and solvent- casting. To reduce the interfacial tension between both polymers, a fraction a of triblock copolymer was added ascompatibilizer to some selected samples. However, the great incompatibility of the components resulted in poor mechanical properties.After this initial evaluation, it was concluded that triblock copolymers were the right solution. Among all the synthetized triblock copolymers, the best candidates were selected for further functionalization. Hydroxyl terminal groups of the copolymers were esterified with modified PEG chains containing carboxyl terminal groups. These PEG-functionalized copolymers were used to prepare scaffolds by a solvent casting/particulate leaching method. Porosity was generated by controlled-size NaCl particles, which were removed by water washing. Scaffolds were functionalized with RGD tripeptide (arginine-glycine-aspartate) to enhance their cell adhesion. Evaluation in vitro confirmed these scaffolds functionalized with PEG and RGD peptides were not cytotoxic to cells and improved cell adhesion and proliferation of two cell cultures.In parallel, it was investigated the enzymatic cyclodepolymerization of the polymacrolactones and the triblock copolymers into macrocyclic oligoesters, and their subsequent repolymerization. This chemical recycling method could be an effective route for the recovering of the monomer species from the copolymers if they are used in other applications such as microelectronics or agriculture.
  

• PEREZ LLANOS, GERMÁN ANIBAL: Application of ultrasound in twin-screw extrusion and microinjection molding: improvements of properties of processed materials and nanocomposites
  
  Author: PEREZ LLANOS, GERMÁN ANIBAL
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Temporary seizure
  Reading date: 18/02/2022
  Thesis director: PUIGGALI BELLALTA, JORGE | DEL VALLE MENDOZA, LUIS JAVIER
  

  Committee:
       PRESIDENT: TYLKOWSKI, BARTOSZ
       SECRETARI: DÍAZ ANDRADE, ANGÈLICA
       VOCAL: ROMERO MORA, JORDI
  Thesis abstract: The plastics industry is in constant evolution looking to improve the properties of new materials and performance in different applications. Currently, the environmental impact associated with the use of plastics is one of the main concerns for the society. It was reflected in regulations at European level such as SUP Directive, Green Deal or studies such as Patents for tomorrow's plastics by European Patent Office on the trends reflected in research on alternative materials to conventional plastic. In order to transfer these new and more sustainable alternatives to an industrial and realistic environment, first applied research has to be carried out on both the development and processes of the materials to optimize their performance.In this thesis study, applied research was carried out using ultrasound technology on different nanocomposites and their transformation processes. Advances in the application of ultrasound for different transformation processes have been studied previously to ensure the approach of the practical study. This study focuses on the application of ultrasound in the process of obtaining new formulations by compounding extrusion and in injection molding, specifically in microinjection. The application of nanotechnology in the development of new materials will allow an improvement in performance and will open a range of new possibilities and applications.To explore the potential of ultrasonic molding (USM) technology, a preliminary process stability study was performed with polypropylene. The evaluation was carried out from a mechanical point of view, in which it was shown that, with an optimization of the process parameters and a correct design approach of the components with the nodal point allow a stability close to production was allowed.To deepen into the potential of USM technology in synergy with new nanocomposite formulations, a comparative study with the conventional microinjection process was performed. Two different nanocomposites based on a biopolymer matrix of poly 3-hydroxybutyrate with Cloisite 20 (organic modification), and with Cloisite 116 (unmodified) were studied. This research reveals that the USM technology, is stable obtaining micro-pieces, maintaining the chemical structure of the initial biocomposite without degrading and homogeneously achieving an exfoliation of both nanoclays. Conventional microinjection did show slight changes in the level of degradation and chemical structure, highlighting that it was not possible to micro-mold samples of the material with the unmodified nanoclay.The stabilization of the compounding extrusion assisted by an ultrasound system has been studied, with a design of a single component that allows the new approach to work in continuous condition and on pre-industrial equipment. Due to the success of the new component, it was possible to carry out the study of new formulations of polypropylene loaded with two different nanoclays (Cloisite 20 and Garamite 1958) and glass bubbles. The new nanocomposites reached the mechanical properties of a conventional material used for door panels in the automotive sector, but with a reduced density. The aim was to demonstrate that it is possible to reduce the weight of plastic components used in the automotive industry and reduce CO2 emissions for a standard vehicle.The research carried out in this thesis work has opened a new field of application to nanocomposites for weight reduction with improved mechanical properties when high level of dispersion is reached. In addition, the potential of USM technology for micro-molding applications has been demonstrated, showing high stability without material degradation during the process, and good dispersion of nano-reinforcements.
  

• SANS MILÀ, JORDI: Design of catalysts based on hydroxyapatite for carbon and nitrogen fixation
  
  Author: SANS MILÀ, JORDI
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Temporary seizure
  Reading date: 08/04/2022
  Thesis director: ALEMAN LLANSO, CARLOS ENRIQUE | TURON DOLS, PAU
  

  Committee:
       PRESIDENT: GONZALEZ VELASCO, JUAN RAMON
       SECRETARI: ESPAÑOL PONS, MONTSERRAT
       VOCAL: GARCÍA DE ARQUER, FRANCISCO PELAYO
       VOCAL: ROIG SERRA, ANNA
       VOCAL: KLEIJ, ARJAN WILLEM
  Thesis abstract: Permanently polarized hydroxyapatite (p-HAp) has been recently proposed as a novel green catalyst. p-HAp is obtained by applying an electrical and thermal stimulation polarization process (TSP), which consists on a DC electric voltage of 500 Vat 1000 °C to previously sintered hydroxyapatite. The objective of this PhD Thesis has been to settle down a solid understanding of p-HAp through the investigation of its structure and physico-chemical features, that results in enhanced electrical and catalytical properties that have allowed to develop novel and outstanding applications in the field of green catalysis. We have focused the research in decarbonization and nitrogen conversion processes that result in high added value molecules. The TSP not only increases the crystallinity, reducing the defects at the crystal lattice, but also creates charges that accumulate at the crystalline boundaries and at the surface of microscopic grains, boosting the electrical conductivity. Hence, the utilization of p-HAp in the catalytic fixation of carbon and nitrogen from CO2, CH4 and N2 gases, has been explored reporting the successful formation of different products of chemical and industrial interest (e.g. amino acids, ethanol and ammonia) as a function of the reaction conditions (i.e. feeding gases and presence/absence of UV illumination). In addition, the catalyst plasticity has been explored to enhance the selectivity towards the desired reaction products. In conclusion, we reveal that p-HAp exhibits important advantages with respect to other consolidated catalysts, drastically increasing the final energetic net balance of the reactions, a fact that opens new avenues in the green chemistry catalysis field.
  

• VALENTI, SOFIA: Physical properties, relaxation dynamics and applications of polymer solid dispersions
  
  Author: VALENTI, SOFIA
  Thesis file: (contact the Doctoral School to confirm you have a valid doctoral degree and to get the link to the thesis)
  Programme: DOCTORAL DEGREE IN POLYMERS AND BIOPOLYMERS
  Department: Department of Chemical Engineering (EQ)
  Mode: Temporary seizure
  Reading date: 11/07/2022
  Thesis director: PUIGGALI BELLALTA, JORGE | MACOVEZ, ROBERTO
  

  Committee:
       PRESIDENT: AFFOUARD, FRÉDÉRIC
       SECRETARI: PÉREZ MADRIGAL, MARIA DEL MAR
       VOCAL: CANGIALOSI, DANIELE
  Thesis abstract: Polymers can have a wide range of application, thanks to the capacity of designing them to meet specific requirements (e.g. mechanical, thermal, optical or electrical). In particular, polymeric materials with high biocompatibility and degradability can be easily prepared, for applications in the biomedical fields as scaffolds for tissue regeneration or matrices for drug delivery. A large number of drugs, in fact, display low solubility and/or poor temporal dissolution profile in aqueous environments. A low solubility, and especially a poor temporal dissolution profile, hinder the bioavailability and thus the implementation of these drugs in pharmaceutical formulations. Besides chemical modification of the drug, also physical strategies are available to enhance bioavailability, such as particle size reduction or amorphization, as well as co-crystal formation or drug dispersion in an appropriate carrier. Amorphous drugs show more solubility and better dissolution profiles (and hence better bioavallability) than crystal phases, in some cases they can be compactad into tablets more effectively than polycrystalline powders, and beneficial effects of amorphous formulations have been reported also in vivo.The amorphous phase is, however, thermodynamically unstable against crystallization and crystalline drug forms dominate the pharmaceutical market for practical and economical reasons. Even so, many drugs with originally poor aqueous solubility have reached the drug development stage, only thanks to its formulation in amorphous phase. One of the ways to improve the dissolution profile of a low-solubility drug and enhance the metastability of its amorphous state, is dispersing it in a polymer excipient with higher water solubility. Such binary mixtures may also allow controlled drug release or even targeted delivery if the dispersion of the drug is carried out in polymers that are only swellable or water-insoluble. lf a polymer is mixed with an inorganic nanofiller, instead of a drug, then the mixture is usually called a polymer nanocomposite. The addition of nanofillers can drastically change and improve the properties of polymers even at low filler content.Nanocomposites can now commercially compete with traditional materials thanks to the great improvements that can be achieved on thermal endurance, flame retardance, liquid and gas impermeability, or targeted electric, electronic and optical properties. While the potential for industrial scale applications of nanocomposites is vast, current applications have been developing ata very slow pace. In many cases, the performance of the rnaterials did not meet the expectations and sorne unexpected drawbacks or flaws were found. Further development of nanocomposites can only be achieved by a specific study of each polymer-filler system, and requires a deep understanding of the interfacial effects between polymer and fillers.While a plethora of studies can be found on small molecules, polymer blends, and polymer solutions, asymmetric binary mixtures (dispersions) of small molecules in polymer matrices have been sornewhat less studied, probably dueto the fact that this type of sample is located at the frontier between molecular physics and chemistry and macromolecular physics, and techniques which are valid for both of them are needed to carry out a comprehensive researcti on these systems. This thesis focuses on binary systems composed by polyrners (macrornolecules) and srnall, organic molecules or inorganic fillers such as carbon nanotubes. We have studied experimentally several distinct molecules (chloramphenicol, diazepam, nordazepam, tetrazepam, curcumin and morniflumate), fillers (carbon nanotubes) and polymers (polylactide, poly(4- hydroxybutyrate), polyurethane anda poly(ester amide)). Different polymer compositions (enantiomeric pure, racemic, or polymer blends) and sample preparation methods, such as film casting and solution or melt-electrospinning, were examined.
  

Last update: 24/09/2022 05:01:10.

Research groups

• AMPC-Analysi of materials in Cultural Heritage
• GBMI-Molecular and Industrial Biotechnology Group
• IMEM-BRT-Innovation in Materials and Molecular Engineering - Biomaterials for Regenerative Therapies
• MACROM-Crystallography, Structure and Function of Biological Macromolecules
• POL-Advanced Industrial Polymers and Technological Biopolymers
• POLQUITEX-Polymeric Materials and Textile Chemistry
• POLTEPO-Thermosetting Epoxy Polymers
• PSEP-Synthetic Polymers: Structure and Properties. Biodegradable Polymers.

Teachers

• Aleman Llanso, Carlos Enrique
• Armelin Diggroc, Elaine
• Bou Serra, Jordi
• Buti Papiol, Salvador
• Cañavate Avila, Francisco Javier
• Colom Fajula, Xavier
• del Valle Mendoza, Luis
• Estrany Coda, Francisco
• Franco Garcia, Lourdes
• Garcia Alvarez, Montserrat
• Garriga Sole, Pere
• Guaus Guerrero, Ester
• Lis Arias, Manuel Jose
• Martinez de Ilarduya Saez de Asteasu, Antxon
• Perez Gonzalez, Juan Jesus
• Puiggali Bellalta, Jordi
• Ramis Juan, Xavier
• Salvado Cabre, Nativitat
• Saperas Plana, Nuria
• Torras Costa, Juan
• Torrent Burgues, Joan
• Tzanov, Tzanko
• Zanuy Gomara, David

• Fernandez Francos, Xavier