Silk fibroin has created a surge of interest for use as organic material due to its optical transparency, biocompatibility, biodegradability, and excellent physical properties. However, the implementation of silk films and structures into biomedical and sensing devices has been relatively low due to a lack of understanding of the mechanisms involved in such implementation. Increasing need for multifunctional high-performance organic materials has caused an emphasis on the ability of researchers to spatiotemporally pattern and control the structure and consequently functional properties of materials. Silk fibroin displays high potential for use as a controllable biomaterial that can be formed into a myriad of different structures for various applications. By implementation of an aqueous silk solution approach combining various fabrication techniques, several different pristine-silk and silk-composite membranes have been developed to investigate the importance of internal structuring. Different methods of investigation include: 1) incorporation of reinforcing nanoparticles within the silk matrix; 2) neutron reflectivity measurements of ultrathin silk films; 3) film patterning with nanoscale features followed by boundary organized surface mineralization of inorganic nanoparticles. The ultimate goal will be to provide fundamental data assisting in an increased knowledge of silk fibroin-based membranes and the effect of secondary structures on properties of interest.

Les composés dits 'bionano' (bionanocomposites) apparaissent comme un nouveau groupe de matériaux hybrides nano-structurés. Ils sont issus de la combinaison de polymères naturels et de solides inorganiques et sont de l'ordre du nanomètre dans au moins une direction. Ces matériaux hybrides conservent les structures et les propriétés fonctionnelles des polymères et matériaux inorganiques dont ils sont composés. Parallèlement, la présence de biopolymères permet de diminuer les risques environnementaux et de santés publiques liés aux nano-matériaux. Les propriétés inhérentes aux biopolymères (biocompatibles' et biodégradables) ouvrent des perspectives intéressantes pour ces matériaux hybrides en particulier dans les domaines de la médecine regénérative et en génie de l'environnement. La production de bionanocomposites de taille plus importante, que les nanoparticules qu'ils renferment, permet d'éviter les effets nocifs potentiels des nanoparticules (NPs) pour les organismes vivants et plus particulièrement pour l'homme. L'association de biopolymères et de nano-solides inorganiques permet la conception de bionanocomposites multifonctionnels qui peuvent être synthétisés et utilisés pour des applications dans des domaines variés. Cette thèse se propose d'étudier principalement (i) ma présence d'arsenic et d'antibiotiques dans les sources d'eau potable en Chine; (ii) l'évaluation d'un nouveau bionanocomposites, à savoir le CGB (chitosan goethite bionanocomposite), dans la décontamination des eaux contenant des espèces inorganiques d'arsenic; (iii) l'évaluation d'argiles comme adsorbants de décontamination de la gentamicine (un antibiotique aminoglycoside ) présent dans l'eau de même que celle de bionanocomposés fait d'argiles riches en gentamicine de polymères de methycelluloses hydroxypropyles Gt-Mt-HPMC (gentamicin-montmorillonite- hydroxypropyl methycellulose) utilisés comme pansement contre les infections qui ont lieu suite à des brûlures. / Bionanocomposites represent an emerging group of nano-structured hybrid materials. They are formed by the combination of natural polymers and inorganic solids and show at least one dimension on the nanometer scale (Darder et al., 2007). These hybrid materials retain the structural and functional properties of nano-structured materials. Meanwhile, the presence of biopolymer can reduce the public health and environmental risk of nano-sized material. The properties inherent to the biopolymers, that is, biocompatibility and biodegradability, open new prospects for these hybrid materials with special incidence in regenerative medicine and in environmental engineering (Darder et al., 2007). Fabrication of large-sized bionanocomposites, rather than nano-sized particles, can prevent possible harmful nanoparticles (NPs) intake by humans and living things. Synergistic assembling of biopolymers with inorganic nano-sized solids leads to multifunctional bionanocomposites which can be synthesized and applied in several areas for designed purposes. This thesis focuses on (i) the presence of toxic arsenic and antibiotics in Chinese drinking water sources; (ii) evaluation of a novel tailored bionanocompsite, namely chitosan goethite bionanocomposite (CGB), as removal agent for inorganic arsenic species from water; (iii) using clay mineral as adsorbent for removing gentamicin, an aminoglycoside antibiotic, from water, and assembling gentamicin-loaded clay with biopolymer hydroxypropyl methycellulose leading to a bionanocomposites film, namely gentamicin-montmorillonite- hydroxypropyl methycellulose (Gt-Mt-HPMC), to be used as burn wound dressing.

Les composés dits 'bionano' (bionanocomposites) apparaissent comme un nouveau groupe de matériaux hybrides nano-structurés. Ils sont issus de la combinaison de polymères naturels et de solides inorganiques et sont de l'ordre du nanomètre dans au moins une direction. Ces matériaux hybrides conservent les structures et les propriétés fonctionnelles des polymères et matériaux inorganiques dont ils sont composés. Parallèlement, la présence de biopolymères permet de diminuer les risques environnementaux et de santés publiques liés aux nano-matériaux. Les propriétés inhérentes aux biopolymères (biocompatibles' et biodégradables) ouvrent des perspectives intéressantes pour ces matériaux hybrides en particulier dans les domaines de la médecine regénérative et en génie de l'environnement. La production de bionanocomposites de taille plus importante, que les nanoparticules qu'ils renferment, permet d'éviter les effets nocifs potentiels des nanoparticules (NPs) pour les organismes vivants et plus particulièrement pour l'homme. L'association de biopolymères et de nano-solides inorganiques permet la conception de bionanocomposites multifonctionnels qui peuvent être synthétisés et utilisés pour des applications dans des domaines variés. Cette thèse se propose d'étudier principalement (i) ma présence d'arsenic et d'antibiotiques dans les sources d'eau potable en Chine; (ii) l'évaluation d'un nouveau bionanocomposites, à savoir le CGB (chitosan goethite bionanocomposite), dans la décontamination des eaux contenant des espèces inorganiques d'arsenic; (iii) l'évaluation d'argiles comme adsorbants de décontamination de la gentamicine (un antibiotique aminoglycoside ) présent dans l'eau de même que celle de bionanocomposés fait d'argiles riches en gentamicine de polymères de methycelluloses hydroxypropyles Gt-Mt-HPMC (gentamicin-montmorillonite- hydroxypropyl methycellulose) utilisés comme pansement contre les infections qui ont lieu suite à des brûlures.

Parmi les différents minéraux argileux, la sépiolite, qui est un silicate fibreux naturel, est un potentiel nano-transporteur prometteur pour le transfert non-viral de biomolécules. Il a en effet été montré que la sépiolite interagissait avec des molécules biologiques telles que les lipides, les polysaccharides et les protéines. Dans ce travail, nous démontrons que la sépiolite interagit également efficacement avec différents types de molécules d'ADN (génomique, plasmidique, oligonucléotides simple et double brin), et nous présentons la première étude détaillée sur les mécanismes d'interaction entre la sépiolite et l'ADN, ainsi qu’une caractérisation physico-chimique de bionanocomposites ADN-sepiolite. Une analyse spectroscopique a montré tout d’abord que l’interaction de l'ADN avec la sépiolite était plus forte en présence de polycations, la valence de ces derniers accroissant le rendement d’absorption, et deuxièmement, que l'ADN ainsi adsorbé pouvait être récupéré avec un rendement modulé par la présence d’EDTA, la structure de l'ADN et son activité biologique étant conservées. Par spectroscopie infrarouge à transformée de Fourier (FTIR) nous avons identifié les groupes silanol externes comme les principaux sites d'interaction avec l'ADN. Nous avons ensuite prouvé qu'il est possible d'utiliser la sépiolite pour extraire l'ADN de bactéries, pour la purification de l'ADN et pour la purification de toute contamination bactérienne. En combinant la microscopie à fluorescence, la microscopie électronique à transmission (MET), la vidéo-microscopie et l’analyse par cytométrie en flux (FACS), nous avons montré que la sépiolite peut être spontanément internalisée dans des cellules de mammifère par le biais de deux voies, l’endocytose et la macropinocytose. En tant que preuve de concept, nous montrons que la sépiolite est capable de transférer de manière stable l'ADN de plasmide dans des bactéries et des cellules de mammifères. Il a également été prouvé qu’en incubant des bactéries avec des bionanocomposites ADN-sepiolite, initialement préparés en présence d'une faible concentration en cations divalents et avec de la sépiolite traitée aux ultrasons (sSep), il était possible d'augmenter l'efficacité de la transformation bactérienne 20 à 30 fois par rapport aux méthodes basées sur l'«effet Yoshida». En outre, nous montrons que l'efficacité du transfert de gènes par la sépiolite peut être optimisée : l'utilisation de sSep et l'exposition à la chloroquine augmentent d’un facteur 100 et 2, respectivement, l’efficacité de transfection. Ces résultats ouvrent la voie à l'utilisation de bionanocomposites à base de sépiolite comme de nouveaux potentiels nano-transporteurs hybrides potentiels, à la fois pour la thérapie génique et le développement de nouveaux modèles biologiques en sciences fondamentales et appliquées. / Among the various clay minerals, sepiolite, which is a natural fibrous silicate, isa potential promising nanocarrier for the non-viral transfer of bio-molecules. Indeed,sepiolite has been shown to interact with biological molecules such as lipids,polysaccharides and proteins. Here, we show that sepiolite efficiently binds differenttypes of DNA molecules (genomic, plasmid, single strand and double strandoligonucleotides), introducing the first detailed study on the interaction mechanismsbetween sepiolite and DNA, as well as the physicochemical characterization of theresulting DNA-sepiolite bionanocomposites. The interaction mechanisms aresuggested to be electrostatic interactions, van der Waals forces, cation bridges, andhydrogen bonding. Spectroscopy analysis showed that the binding of DNA to sepiolitewas increased by polycations with valence dependent efficiency, and the DNApreviously adsorbed could be recovered with an efficiency that could be modulatedusing a chelating agent (EDTA), preserving the DNA structure and biological activity.Fourier-transform infrared spectroscopy identified the external silanol groups as themain sites of interaction with the DNA. It was proved that it is possible to use sepiolitefor extracting DNA from bacteria, for DNA purification and for purification from bacterialcontamination. By combining fluorescence microscopy, transmission electronmicroscopy (TEM), time-lapse video microscopy and flow cytometry analysis (FACS),we show that sepiolite can be spontaneously internalized into mammalian cells throughboth endocytic and non-endocytic pathways. As a proof of concept, we show thatsepiolite is able to stably transfer plasmid DNA into bacteria and mammalian cells. Itwas also proved that with the incubation of bacteria with the Sep/DNAbionanocomposite initially prepared in the presence of a low concentration of divalentcation, and using sonicated sepiolite (sSep), it is possible to increase the bacterialtransformation efficiency from 20 to 30-fold compared to previously reported methodswhich are based in the “Yoshida effect”. Additionally, we show that the efficiency ofsepiolite-mediated gene transfer can be optimized: the use of sSep and the exposureto the endosome disrupter chloroquine 100-fold and 2-fold stimulated DNA transfectionefficiency, respectively. These results open the way to the use of sepiolite-basedbionanocomposites as a novel class of hybrid nanocarriers for both potential genetherapy and the development of novel biological models of interest for academic andapplied sciences.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, the effects of the incorporation were valued of cellulose nanocrystals of the wood pulp of Eucalyptus urograndis from three different times of acid hydrolysis (20, 50 and 80 minutes) in order to determine which of three types of nanocrystals would be most appropriate in the reinforcement function for the matrix of apple pectin. The films were characterized using dynamic mechanical thermal analysis to choose the best reinforcement element in terms of improvement in mechanical properties. After choosing the appropriate filler, new nanocomposites were produced with the percentages of 1, 2, 4 and 8% w/w in relative to the final mass of 0.5 g of each nanocomposite film. The films were manufactured by casting method, in the presence and absence of glycerol as plasticizer in the formulations. These nanocomposite films were characterized using the techniques of water vapor permeability and gases, with the aim of evaluating the barrier properties, contact angle with water in order to verify the hydrophillicity of the material, and dynamic mechanical thermal analysis for evaluating mechanical properties. The nanocrystals extracted with fifty minutes hydrolysis (NC50) were the ones that stood out in terms of improvement in mechanical properties, due to the significant increase in the values of E\'. The nanocomposite films acted as a barrier to passage of gases due to its dense structure, without pores and homogeneous. The formulations of the nanocomposite films with 8% w/w of cellulose nanocrystals in the absence and presence of glycerol were used for coating of strawberries, the comparatives were made with poly (vinyl chloride) film, in relation to weight loss (%) and texture analysis in terms of Puncture Strength the film and Puncture deformation suffered by them. The results showed that the nanocomposite films with glycerol and poly (vinyl chloride) showed comparable values in terms of weight loss, and the glycerol incorporation provided a gain in flexibility of these films. Additionally this same formulation was used in the formulations of the edible coatings and the incorporation of essential oil of lemon grass in the formulations, in order to study the antifungal potential of this compound for coating strawberries. The formulation (18.20 mL of suspension the cellulose nanocrystals fifty minutes, NC50, 230 mL of suspension of apple pectin, 0.50 mL glycerol and 0.12 mL of essential oil of lemon grass) whose processes of immersion were performed twice. This formulation, was the one that stood out in terms of reduction of weight loss, around 5% for the strawberry coated with this formulation and on the other hand 12% for uncoated, analyzed in the time of two days, time that these fruits should be consumed when fresh and stored under satisfactory conditions. So with this work it was observed that the addition of cellulose nanocrystals acted as reinforcement elements for the matrix in the study, these films are hydrophilic and acted as a barrier to passage of gases. The addition of glycerol causes changes in mechanical, thermal and barrier properties of the nanocomposites. According to applicability tests the same base formulation can be used in two different perspectives: coating strawberries in the form of films and as ingredients for preparing the edible coatings to extend shelf life of these fruits which have an extremely short life-time due to rapid metabolism thereof. / Neste trabalho, foram avaliados os efeitos da incorporação de nanocristais de celulose da polpa de madeira de Eucalyptus urograndis a partir de três tempos distintos de hidrólise ácida (20, 50 e 80 minutos) a fim de determinar qual dos três tipos de nanocristais seria o mais adequado na função de reforço para a matriz de pectina de maçã. Os filmes foram caracterizados utilizando análise térmica dinâmico mecânica, para a escolha do melhor elemento de reforço em termos de melhora nas propriedades mecânicas. Após a escolha do elemento de reforço mais adequado, novos nanocompósitos foram produzidos com as percentagens de 1, 2, 4 e 8% m/m em relação à massa final de 0,5 g de cada filme nanocompósito. Os filmes foram obtidos através do método de casting, na presença e na ausência de glicerol como plastificante nas formulações. Estes filmes nanocompósitos foram caracterizados através das técnicas de permeação aos vapores de água e a gases, com intuito de se avaliar as propriedades de barreira, ângulo de contato em água a fim de verificar a hidrofilicidade dos materiais, e análise térmica dinâmico mecânica para avaliação das propriedades mecânicas. Os nanocristais extraídos com cinquenta minutos de hidrólise (NC50) foram os que mais se destacaram em termos de melhora em propriedades mecânicas, devido ao aumento significativo nos valores de E‟. Os filmes nanocompósitos atuaram como barreira a passagem de gases, devido a sua estrutura densa, homogênea e sem poros. As formulações dos filmes nanocompósitos com 8% m/m de nanocristais de celulose na ausência e na presença de glicerol foram utilizados no revestimento de morangos, e os devidos comparativos foram feitos com o filme de policloreto de vinila, com relação à perda de massa (%) e análise de textura em termos de força máxima para a perfuração dos filmes, bem como a deformação sofrida pelos mesmos. Os resultados mostraram que os filmes nanocompósitos com glicerol e policloreto de vinila apresentaram valores comparáveis em termos de minimização de perda de massa, e a incorporação do glicerol proporcionou um ganho em flexibilidade destes filmes. Adicionalmente esta mesma formulação foi usada nas formulações dos revestimentos comestíveis, além da incorporação do óleo essencial de capim-limão as formulações com a finalidade de estudar a potencialidade antifúngica deste composto para revestir morangos. Os devidos comparativos foram feitos com os morangos não revestidos. A formulação (18,20 mL de suspensão de nanocristais de celulose, NC50, 230 mL de suspensão de pectina de maçã, 0,50 mL de glicerol e 0,12 mL de óleo essencial de capim-limão) cujos processos de imersão foram realizados por duas vezes. Sendo esta, a que mais se destacou em termos de redução de perda de massa em torno de 5% para o morango revestido com esta formulação e em contrapartida 12% para o não revestido, analisados no tempo de dois dias, tempo esse que estes frutos devem ser consumidos quando in natura e armazenados sob condições satisfatórias. Assim, com este trabalho foi possível observar que a adição de nanocristais de celulose atuou como elementos de reforço para a matriz em estudo, os filmes são hidrofílicos e atuaram como barreira a passagem de gases. A adição de glicerol provocou alterações nas propriedades mecânicas, de barreira e térmica dos nanocompósitos. E diante dos testes de aplicabilidade, uma mesma formulação base pode ser empregada em duas perspectivas distintas: para revestir morangos na forma de filmes e como ingredientes para o preparo dos revestimentos comestíveis, a fim de se estender o tempo de prateleira destes frutos que é extremamente curto, devido ao metabolismo acelerado dos mesmos. / Mestre em Química

The uniform dispersion of the nano fillers without agglomeration in a polymeric matrix is widely adapted for the purpose of mechanical properties enhancement. In the context to biomedical applications, the type and amount of nanoparticles can potentially influence the biocompatibility. In order to address these issues, High Density Polyethylene (HDPE) based composites reinforced with graphene oxide (GO) were prepared by melt mixing followed by compression moulding. In an attempt to tailor the dispersion and to improve the interfacial adhesion, polyethylene (PE) was immobilized onto GO sheets by nucleophilic addition-elimination reaction. A good combination of yield strength (ca. 20 MPa), elastic modulus (ca. 600 MPa) and an outstanding elongation at failure (ca. 70 %) were recorded with 3 wt % polyethylene grafted graphene oxide (PE-g-GO) reinforced HDPE composites. Considering the relevance of protein adsorption as a biophysical precursor to cell adhesion, the protein adsorption isotherms of bovine serum albumin (BSA) were determined to realize three times higher equilibrium constant (Keq) for PE-g-GO reinforced HDPE composites as compared to GO reinforced composites. In order to assess the cytocompatibility, osteoblast cells (MC3T3) were grown on HDPE/GO and HDPE/PE-g-GO composites, in vitro. The statistically significant increase in metabolically active cell was observed, irrespective of the substrate composition. Such observation indicated that HDPE with GO or PE-g-GO addition (upto 3 wt %) can be used as cell growth substrate. The extensive proliferation of cells with oriented growth pattern also supported the fact that tailored GO addition can support cellular functionality, in vitro. Taken together, the experimental results suggest that the PE-g-GO in HDPE can effectively be utilized to enhance both mechanical and cytocompatibility properties and can further be explored for potential biomedical applications.

<p>U ovom radu, izvr&scaron;ena je sinteza i karakterizacija bionanokompozitnih materijala na osnovu poli(laktida) i vi&scaron;eslojnih ugljeničnih nanocevi. Ispitivan je uticaj različitih tehnika funkcionalizacije nanocevi, kao i izbor uslova sinteze i odnosa polaznih komponenti sistema, na svojstva dobijenih kompozitnih materijala na osnovu poli(L-laktida). Radi postizanja uniformne raspodele nanopunila u kompozitima, vi&scaron;eslojne ugljenične nanocevi su modifikovane hemijskom i radijacionom funkcionalizacijom. Izvr&scaron;ena je karakterizacija ugljeničnih nanocevi, sa ciljem utvrđivanja uspe&scaron;nosti primenjenih tehnika modifikacije na njihova svojstva i stepen funkcionalizacije. Metodom in situ polimerizacije L-laktida sa povr&scaron;ina modifikovanih nanocevi, pripremljene su serije uzoraka kompozitnih materijala sa različitim sadrţajem funkcionalizovanih nanocevi. Detaljno je ispitan uticaj funkcionalizovanih nanocevi na toplotna, kristalna, morfolo&scaron;ka, mehanička i električna svojstva sintetisanih kompozitnih materijala. Postignuta homogena disperzija nanocevi unutar biorazgradive, biokompatibilne matrice polimera koji se dobija iz obnovljivih sirovina, uticala je na pobolj&scaron;anje svojstava, kao i na uspostavljanje novih funkcionalnosti dobijenih materijala. Značajno pobolj&scaron;anje toplotnih i mehaničkih svojstva sintetisanih materijala, zajedno sa postignutom električnom provodljivo&scaron;ću, omogućava pro&scaron;irenje oblasti primene kompozita na osnovu poli(laktida) i ugljeničnih nanocevi.</p> / <p>In this thesis, bionanocomposites based on poly(lactide) and multi-walled carbon nanotubes were synthesized and characterised. Poly(L-lactide) was used as a matrix for the composite synthesis; the influence of nanofillers content, the methods of their functionalization, as well as the synthesis parameters, on the properties of obtained materials were investigated. In order to achieve a uniform dispersion of nanofillers in composite materials, multi-walled carbon nanotubes were modified using chemical and radiation functionalization. Characterization of carbon nanotubes was performed in order to determine the influence of applied modification techniques on their properties and degree of functionalization. A series of composite materials with different content of modified nanotubes were prepared by in situ polymerization of L-lactide from the surface of functionalized nanotubes. The influence of functionalized nanotubes on the thermal, crystal, morphological, mechanical and electrical properties of synthesized composites was investigated in detail. The homogeneous dispersion of carbon nanotubes within the biodegradable, biocompatible, biobased polymer matrix, has influenced the improvement of the properties, as well as the acquiring of new functionalities of synthesized materials. The significant improvement of thermal and mechanical properties of composites, and the achievement of its electrical conductivity, allow the field of application of composites based on poly(lactide) and carbon nanotubes to be expanded.</p>

PhD (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Water is a basic resource to mankind. The environment is deteriorating daily due to industrial pollution of water resources. Industrial effluents containing organic pollutants such as dyes are undesirable even at low concentrations in the environment. Natural biomaterials have been applied as adsorbents for dye removal from water systems, however, their application has been limited by their low adsorption capacity. Much attention has been focused on the chemical modification of natural biomass via grafting processes. The modification of natural polymers by graft copolymerization is a promising technique since it functionalizes a biopolymer thus imparting desirable properties. The purpose of the study was to prepare and optimize the working conditions for the pine-magnetite bionanocomposites (PMC) as adsorbents and as photocatalysts modifiers. First, this work focuses on the synthesis and optimization of reaction variables in the preparation of PMC for the removal of methylene blue (MB). The thesis also explores the synthesis of acrylamide and acrylic acid-grafted PMC, resulting in the formation of acrylamide-grafted PMC (GACA) and acrylic acid-grafted pine-magnetite bionanocomposites (GAA), respectively. The grafting of functional groups such as –CO, –NH2 onto cellulose from acrylamides is also explored in detail. The adsorption conditions optimized were used to investigate the adsorption efficiency of GAA and GACA on MB. Finally, the application of PMC and GAA as modifiers for amorphous TiO2 and N-doped TiO2was carried out. The photocatalytic bionanocomposites from PMC (namely PMC–a-C,TiO2 and PMC–a-C,NTiO2) and those from GAA (labeled GAA–a-C,TiO2 and GAA–a-C,NTiO2) are compared by their photocatalytic efficiency on the degradative removal of an alkaline dye mixture formed from Reactive red 120 (RR 120) and Rhodamine B (Rh B). The synthesis procedure for PMC involved treating pinecone biomass with 0.15 M NaOH solution to remove unwanted plant extracts and the subsequent coating of the treated pinecone with iron oxide magnetic particles through a co-precipitation method. The variables used for the experiments were volume of NH4OH (5 to 40 cm3), reaction temperature (40 to 100 °C), effect of time (15 to 60 min) and mass (1.0 to 3.5 g). The PMC and acrylic acid grafted pine-magnetite composite (GAA) were probed for structural morphology and surface properties using various surface characterization instrumental techniques. Strong chemical interactions between pinecone magnetite and acrylic acid were demonstrated by thermogravimetric (TGA), differential thermal analysis (DTA) and X-ray photoelectron spectroscopy (XPS) for these unique bionanocomposites as such suggesting high chemical stability. Grafting acrylic acid was shown by XPS to form polyacrylic acid on the surface of the bionanocomposites and thus capping the surface groups. Significant differences in size were shown by transmission electron spectroscopy (TEM) and scanning electron microscopy (SEM); i.e., smaller particle sizes (Ave = 13.0 nm) for GAA and slightly larger for PMC (Ave = 14.0 nm). Brunauer Emmett Teller (BET) surface analysis demonstrated a larger surface area, pore volume and pore diameter (59.9 m2.g-1, 0.2254 cm3.g-1 and 28.14) for GAA compared to PMC. These characteristics coupled with the point of zero charge for GAA (pHpzc = 6.8) were critical in enhancing the efficiency of GAA adsorption of MB at pH 12 and further enable GAA to have a higher desorption efficiency of up to 99.7% after four cycles of washing with 0.10 M HCl. The adsorption kinetics and isotherm studies indicated that the adsorption process follows the pseudo second order kinetics and Langmuir isotherm respectively. The adsorbent also showed improvement in the adsorption capacity and reusability promising to be used for the removal of dyes in a prototype scale. GAA and MB adsorption mechanism was confirmed to be through intra particle diffusion. The overall performance of the GAA bionanocomposites is hinged on the formation of polyacrylic acid on the surface, its structural morphology, and the enhanced surface properties. Most importantly, the plant-based materials (lignin and cellulose) provide an environment that is rich with surface (–COOH and –OH) groups for the attachment of the magnetite nanoparticles while the polyacrylic acid stabilizes the magnetite onto the pinecone nanoparticles while reducing the point of zero charge for increased adsorption of cationic species. The photocatalytic bionanocomposites were fabricated from the adsorptive bionanocomposites using a simple solgel process in which ~10 wt.% of PMC and GAA, respectively, were used as a starting agent. Titanium butoxide was used as a precursor, acetylacetone as a dispersant and ethylene diamine as a nitrogen source. Using this procedure, amorphous carbon-doped titania (a-C,TiO2) and amorphous carbon and nitrogen co-doped titania (a-C,NTiO2) were fabricated except that the biopolymer was not added. Two sets of amorphous titania bionanocomposites were fabricated. One set was the nitrogen doped forms that had been modified with PMC and GAA (PMC–a-C,TiO2 and GAA–a-C,NTiO2). The other set of photocatalytic bionanocomposites produced in this work were without nitrogen (PMC–a-C,TiO2 and GAA–a-C,TiO2). TEM and SEM micrographs showed that all the photocatalysts consisted of globular, smooth aggregates of nanosized a-CTiO2 and a-C,NTiO2 which decreased in size with N-doping and the incorporation of GAA and PMC to as low as <30 nm. Surface chemical analysis through FTIR, XPS and EDS confirmed the presence of C, O, Ti and N (for the N-doped photocatalysts). In addition, it was demonstrated that N-doping into TiO2 had taken place, albeit with most of the N incorporated as organic nitrogen. It was further demonstrated that because of the absence of high temperature calcination, the process chemicals played a significant role in doping the photocatalysts with carbon resulting in the promotion of photocatalytic activity for a-C,TiO2 to the point of surpassing that of, a-C,NTiO2 and all the PMC-modified photocatalytic bionanocomposites. a-C,TiO2 had an overall 94% removal of the dyes, Rhodamine B (RhB) and Reactive red 120(RR 120), under UV illumination. The benefit of co-doping a-TiO2 with C, N and the biopolymers was realized with the incorporation of GAA as a modifier. The result was 97% removal of the dyes by GAA–a-CTiO2 and 99% for GAA–a-C,NTiO2. It was further observed that the degradation of the binary mixture of the dyes (RhB and RR 120) proceeded through the zero order kinetics for the a-C,TiO2 based photocatalysts and first order kinetics for the N-doped photocatalysts. The work, has, therefore demonstrated the applicability of plant-based biopolymers in the fabrication of nanoadsorbents and nanophotocatalysts. While the photocatalytic degradations were carried out under UV-light, there still remains a number of possible avenues that researchers can build on to improve the visible light-driven photocatalytic bionanocomposites. The research work has proven the effectiveness of novel pinecone magnetic nanoparticle materials and TiO2-based photocatalyst for the degradation of undesirable dyes from wastewater.