The first part of this thesis is concerned with thestructure-property relationships in nonionic surfactantsystems. The main aim was to investigate how the surfactantstructure influences the adsorption at interfaces andinteractions between surfactant coated interfaces.Particularly, the effect of the structure of the surfactantheadgroups was investigated. These were sugar-based headgroupwith varying size and flexibility and poly(ethylene oxide)based headgroups with or without an additional amide or estergroup. The hydrophobic part of the surfactant consisted mostlyof straight alkyl chains, except for one type of poly(ethyleneoxide) based surfactant with a dehydroabietic hydrophobe. The main technique that was used is the surface forcetechnique, with which the forces acting between two adsorbedsurfactant layers on hydrophilic or hydrophobic surfaces can bemeasured. These forces are important for e.g. the stability ofdispersions. The hydrophilic surfaces employed were glass andmica, whereas the hydrophobic surfaces were silanized glass andhydrophobized mica. The adsorption behavior on hydrophilicsurfaces is highly dependent on the type of headgroup andsurface, whereas similar results were obtained on the two typesof hydrophobic surfaces. To better understand how the surfaceforces are affected by the surfactant structure, measurementsof adsorbed amount and theoretical mean-field latticecalculations were carried out. The results show that the sugarsurfactant layers and poly(ethylene oxide) surfactant layersgive rise to very different surface forces, but that the forcesare more similar within each group. The structure-propertyrelationships for many other physical properties have beenstudied as well. These include equilibrium and dynamicadsorption at the liquid-vapor interface, micelle size, micelledynamics, and wetting. The second part in this thesis is about the aggregationbetween cationic polyelectrolytes and an anionic surfactant.The surface force technique was used to study the adsorption ofa low charged cationic polyelectrolyte on mica, and theaggregation between the adsorbed polyelectrolyte with theanionic surfactant. The aggregation in bulk was studied withturbidimetry, small angle neutron scattering (SANS), and smallangle x-ray scattering (SAXS). An internal hexagonal aggregatestructure was found for some of the bulk aggregates. <b>Keywords:</b>nonionic surfactant, sugar surfactant,poly(ethylene oxide), amide, ester, polyelectrolyte, SDS,hydrophobic surface, glass surface, mica, adsorption,aggregation, micelle size, surface forces, wetting, dynamicsurface tension, NMR, TRFQ, SANS, SAXS, mean-field latticecalculations.

<p>The first part of this thesis is concerned with thestructure-property relationships in nonionic surfactantsystems. The main aim was to investigate how the surfactantstructure influences the adsorption at interfaces andinteractions between surfactant coated interfaces.Particularly, the effect of the structure of the surfactantheadgroups was investigated. These were sugar-based headgroupwith varying size and flexibility and poly(ethylene oxide)based headgroups with or without an additional amide or estergroup. The hydrophobic part of the surfactant consisted mostlyof straight alkyl chains, except for one type of poly(ethyleneoxide) based surfactant with a dehydroabietic hydrophobe.</p><p>The main technique that was used is the surface forcetechnique, with which the forces acting between two adsorbedsurfactant layers on hydrophilic or hydrophobic surfaces can bemeasured. These forces are important for e.g. the stability ofdispersions. The hydrophilic surfaces employed were glass andmica, whereas the hydrophobic surfaces were silanized glass andhydrophobized mica. The adsorption behavior on hydrophilicsurfaces is highly dependent on the type of headgroup andsurface, whereas similar results were obtained on the two typesof hydrophobic surfaces. To better understand how the surfaceforces are affected by the surfactant structure, measurementsof adsorbed amount and theoretical mean-field latticecalculations were carried out. The results show that the sugarsurfactant layers and poly(ethylene oxide) surfactant layersgive rise to very different surface forces, but that the forcesare more similar within each group. The structure-propertyrelationships for many other physical properties have beenstudied as well. These include equilibrium and dynamicadsorption at the liquid-vapor interface, micelle size, micelledynamics, and wetting.</p><p>The second part in this thesis is about the aggregationbetween cationic polyelectrolytes and an anionic surfactant.The surface force technique was used to study the adsorption ofa low charged cationic polyelectrolyte on mica, and theaggregation between the adsorbed polyelectrolyte with theanionic surfactant. The aggregation in bulk was studied withturbidimetry, small angle neutron scattering (SANS), and smallangle x-ray scattering (SAXS). An internal hexagonal aggregatestructure was found for some of the bulk aggregates.</p><p><b>Keywords:</b>nonionic surfactant, sugar surfactant,poly(ethylene oxide), amide, ester, polyelectrolyte, SDS,hydrophobic surface, glass surface, mica, adsorption,aggregation, micelle size, surface forces, wetting, dynamicsurface tension, NMR, TRFQ, SANS, SAXS, mean-field latticecalculations.</p>

<p>In this thesis the structure and hydration of small organic and amphipilic compounds adsorbed at the air-liquid interface, have been studied using the nonlinear optical technique Vibrational Sum Frequency Spectroscopy (VSFS). The second order nature of the sum frequency process makes this technique particularly surface sensitive and very suitable for interfacial studies, as molecules at the surface can be distinguished even in the presence of a vast excess of the same molecules in the bulk. Particular emphasis was given to the surface water structure and how it is affected by the presence of small model compounds such as acetic acid and formic acid, and also non-ionic surfactants with sugar based and ethylene oxide based polar headgroups. Understanding the structure of water at these interfaces is of considerable fundamental importance, and here VSFS provided unique information. Upon addition of tiny amounts of these surface active compounds, the ordered surface structure of water was found to be significantly perturbed, as revealed by the changes observed in the characteristic spectroscopic signature of the dangling OH bond of water molecules, which vibrate free in air and are present in the top monolayer. Dramatic differences between the different compounds were also observed in the bonded OH region, providing a valuable insight into the hydration of polar groups at interfaces. Additionally, by employing different polarization combinations of the laser beams involved in the sum frequency process, information about the different water species present at the surface and their average orientation were extracted. In particular an unusual state of water was found with a preferred orientation in a non-donor configuration in close proximity to the hydrophobic region formed by the hydrocarbon tails of the surfactant molecules.</p><p>The conformation and orientation of the different adsorbates were also characterized, targeting their specific vibrational frequencies. Noteworthy is the orientation of the fluorocarbon chain of ammonium perfluorononanoate (APFN), which in contrast to the hydrocarbon chains of the other surfactant molecules studied, remained constant over a wide range of surface densities. This behaviour was also observed for the anionic headgroup of sodium dodecyl sulphate (SDS). Other interesting findings were the formation of a cyclic dimer bilayer at the surface of concentrated aqueous solutions of acetic acid and the water structuring effect induced by poly(ethylene-oxide) headgroups, in spite of being themselves disordered at the air-liquid interface.</p>

Cancer is the second leading cause of death in the United States and its onset is highly incident in the lungs, with very low long-term survival rates. Chemotherapy plays a significant role for lung cancer treatment, and pulmonary delivery may be a potential route for anticancer drug delivery to treat lung tumors. Coenzyme Q₁₀ (CoQ₁₀) is a poorly-water soluble compound that is being investigated for the treatment of carcinomas. In this work, we hypothesize that formulations of CoQ10 may be developed for pulmonary delivery with a satisfactory pharmacokinetic profile that will have the potential to improve a pharmacodynamic response when treating lung malignancies. The formulation design was to use a vibrating-mesh nebulizer to aerosolize aqueous dispersions of CoQ₁₀ stabilized by phospholipids physiologically found in the lungs. In the first study, a method was developed to measure the surface tension of liquids, a physicochemical property that has been shown to influence the aerosol output characteristics from vibrating-mesh nebulizers. Subsequently, this method was used, together with analysis of particle size distribution, zeta potential, and rheology, to further evaluate the factors influencing the capability of this nebulizer system to continuously and steadily aerosolize formulations of CoQ₁₀ prepared with high pressure homogenization. The aerosolization profile (nebulization performance and in vitro drug deposition of nebulized droplets) of formulations prepared with soybean lecithin, dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC) were evaluated. The rheological behavior of these dispersions was found to be the factor that may be indicative of the aerosolization output profile. Finally, the pulmonary deposition and systemic distribution of CoQ₁₀ prepared as DMPC, DPPC, and DSPC dispersions were investigated in vivo in mice. It was found that high drug amounts were deposited and retained in the mouse lungs for at least 48 hours post nebulization. Systemic distribution was not observed and deposition in the nasal cavity occurred at a lower scale than in the lungs. This body of work provides evidence that CoQ₁₀ may be successfully formulated as dispersions to be aerosolized using vibrating-mesh nebulizers and achieve high drug deposition in the lungs during inhalation. / text

The interaction of a liquid drop with a solid surface is being actively studied to understand practically encountered scenarios such as the impact of fuel spray droplets onto the walls of engine combustion chamber, the formation of thermal barrier coating on the surfaces of turbine blades, the process of ink-jet printing, etc. The surface topography of solid surface is one of the major parameters influencing the dynamics of drop-surface interaction process. Understanding the precise role of surface topography features such as micro asperities and grooves on the spreading and receding processes of impacting liquid drops is crucial for the improvement in abovementioned applications. Recent developments in the fabrication of micro- and nano-structures on solid surfaces provide fabulous opportunities to investigate the role of single/multiple micro asperities and grooves on the dynamics of impacting drops. The thesis deals with an experimental work on the impact of water drops on stainless steel surfaces comprising unidirectional parallel grooves. A group of six target grooved surfaces covering a wide range of surface wettability were considered. The target surfaces were prepared using the techniques of photolithography, electro discharge machining, and laser machining. Scanning electron microscope and optical surface profilometer were used to characterize the groove texture geometrical parameters of the target grooved surfaces. The experiments of drop impact were carried out in an experimental apparatus consisting of a liquid drop generator, a substrate table, and a digital video imaging system. Free-falling distilled water drops released from a certain height were allowed to impact normally on the target surfaces. The image sequences of drop impact dynamics were constructed from the images captured using the digital video imaging system. Majority of the drop impact experiments were captured using a high speed video camera operating with frame speed ranging from 3000 to 10000 fps. For the target grooved surfaces, the impact dynamics was analyzed for the impacting drop liquid oriented both in the direction perpendicular to the grooves ( ) and in the direction parallel to the grooves (||) via independent test runs. The captured digital frames were used to deduce the temporal variation of impacting drop parameters such as drop contact diameter, drop contact angle, and drop height at the center of impacting drop with the aid of image processing software. The impacting drops were characterized in terms of Weber number, We expressed in terms of drop impact velocity and drop diameter measured just before the start of impact process. The study covered We ranging from 1.8 to 170. In general, the groove texture on the solid surface influences the drop impact process for all We examined in the study. The effect is more pronounced for the receding of impacting drops. For high We drops, the groove texture enhances the perturbations seen at the periphery of spreading lamella. The study showed quantitatively that the drop impact process on a target grooved surface comprising unidirectional parallel grooves develops a non-axisymmetric drop flow on the grooved surface exhibiting different spreading and receding processes of impacting drop liquid in the directions perpendicular ( ) and parallel (||) to the grooves. The maximum spreading diameter reached immediately after the completion of early inertia-dominated spreading in is less than that obtained in || due to the loss of drop kinetic energy caused by the pinned motion of drop liquid in . The non- axisymmetric drop flow on the target grooved surface develops a difference between the frequencies of contact angle oscillation of impacting drop liquid in  and ||. The frequency difference in contact angle oscillation causes the beating phenomenon in the temporal variation of the contact angle anisotropy, Δθ and drop height at the center of impacting drop, Z. For a given target grooved surface, the experimental measurements suggested that the beat frequency is almost independent of We. The temporal variation of Δθ and Z do not show the traces of beating phenomenon for the impact of high We drops. Owing to the non-axisymmetric drop flow, the final equilibrium drop shape is eccentric for the impact of low We drops and approaches a circular shape for the impact of high We drops. The role of groove texture geometrical parameters is seen in the drop impact process via the surface wettability especially for the impact of low We drops. Larger surface roughness factor makes the target grooved surface to exhibit hydrophobic characteristics.

Cancer is the second leading cause of death in the United States and its onset is highly incident in the lungs, with very low long-term survival rates. Chemotherapy plays a significant role for lung cancer treatment, and pulmonary delivery may be a potential route for anticancer drug delivery to treat lung tumors. Coenzyme Q₁₀ (CoQ₁₀) is a poorly-water soluble compound that is being investigated for the treatment of carcinomas. In this work, we hypothesize that formulations of CoQ10 may be developed for pulmonary delivery with a satisfactory pharmacokinetic profile that will have the potential to improve a pharmacodynamic response when treating lung malignancies. The formulation design was to use a vibrating-mesh nebulizer to aerosolize aqueous dispersions of CoQ₁₀ stabilized by phospholipids physiologically found in the lungs. In the first study, a method was developed to measure the surface tension of liquids, a physicochemical property that has been shown to influence the aerosol output characteristics from vibrating-mesh nebulizers. Subsequently, this method was used, together with analysis of particle size distribution, zeta potential, and rheology, to further evaluate the factors influencing the capability of this nebulizer system to continuously and steadily aerosolize formulations of CoQ₁₀ prepared with high pressure homogenization. The aerosolization profile (nebulization performance and in vitro drug deposition of nebulized droplets) of formulations prepared with soybean lecithin, dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC) were evaluated. The rheological behavior of these dispersions was found to be the factor that may be indicative of the aerosolization output profile. Finally, the pulmonary deposition and systemic distribution of CoQ₁₀ prepared as DMPC, DPPC, and DSPC dispersions were investigated in vivo in mice. It was found that high drug amounts were deposited and retained in the mouse lungs for at least 48 hours post nebulization. Systemic distribution was not observed and deposition in the nasal cavity occurred at a lower scale than in the lungs. This body of work provides evidence that CoQ₁₀ may be successfully formulated as dispersions to be aerosolized using vibrating-mesh nebulizers and achieve high drug deposition in the lungs during inhalation.

Made available in DSpace on 2014-12-17T14:07:03Z (GMT). No. of bitstreams: 1 ThercioHCC_TESE.pdf: 3355689 bytes, checksum: 0848bf4db8c96f8922893ef41d7b36f0 (MD5) Previous issue date: 2010-03-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work reports the influence of the poly (ethylene terephthalate) textile and films surface modification by plasmas of O2 and mixtures (N2 + O2), on their physical and chemical properties. The plasma surface polymeric modification has been used for many researchs, because it does not affect the environment with toxic agents, the alterations remains only at nanometric layers and this technique shows expressive results. Then, due to its good acceptance, the treatment was carried out in a vacuum chamber. Some parameters remained constant during all treatment, such as: Voltage 470 V; Pressure 1,250 Mbar; Current: 0, 10 A and gas flow: 10 cm3/min, using oxygen plasma alternating the treatment time 10 to 60 min with an increase of 10 min to each subsequent treatment. Also, the samples were treated with a gas mixture (nitrogen + oxygen) which was varied only the gas composition from 0 to 100% leaving the treatment time remaining constant to all treatment (10 min). The plasma treatment was characterized in-situ with Optics Emission Spectroscopy (OES), and the samples was characterized by contact angle, surface tension, Through Capillary tests, Raman spectroscopy, Infrared attenuated total reflection (IR-ATR) and atomic force microscopy, scanning electronic Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The results showed that oxygen treated fabrics presented high wettability, due to the hydrophilic groups incorporation onto the surface formed through spputering of carbon atoms. For the nitrogen atmosphere, there is the a film deposition of amine groups. Treatment with small oxygen concentration in the mixture with nitrogen has a higher spputered species of the samples / Neste trabalho, investigou-se a influ?ncia do tratamento superficial a plasma utilizando como gases de trabalho o oxig?nio e uma mistura de nitrog?nio + oxig?nio, sobre as propriedades f?sicas e qu?micas de tecidose filmes de Poli?ster. A modifica??o superficial de superf?cies polim?ricas por plasma tem sido bastante utilizada, pois a mesma n?o apresenta agentes nocivos ao ambiente, ?s altera??es promovidas no material s?o de escala nanom?tricas, e comprovadamente ? a t?cnica que tem apresentado resultados mais expressivos. Ent?o, tendo em vista a boa aceitabilidade do uso do plasma em materiais polim?ricos, O tratamento foi realizado em uma c?mara contendo os gases de trabalho sob baixa press?o (~ 1 mbar) mantendo-se constante durante todo ensaio alguns par?metros do plasma, tais como, voltagem: 470 V; press?o: 1,250 mbar; corrente: 0,10 A e fluxo de g?s: 10 cm3/min, usando plasma com atmosfera gasosa de oxig?nio variando-se o tempo de tratamento de 10 - 60 min com incremento de 10 min a cada tratamento subseq?ente, e tamb?m usou-se a atmosfera gasosa composta por uma mistura de nitrog?nio e oxig?nio, variando a concentra??o gasosa dos mesmos (de 0 100%), para um tempo de tratamento de 10 min. O tratamento por plasma foi caracterizado in-situ com o auxilio da Espectroscopia de Emiss?o ?tica,e as amostras foram caracterizadas por medidas de ?ngulo de contato, tens?o superficial, arraste capilar, espectroscopia Raman, Espectroscopia de infravermelho de reflex?o total atenuada (IR-ATR), e microscopia de for?a at?mica (AFM), Microscopia Eletr?nica de Varredura (MEV) e por espectroscopia de fotoel?trons excitados por raios-X (XPS). Os resultados mostraram que tecidos tratados com atmosfera de oxig?nio apresentaram elevada molhabilidade, devido a incorpora??o de grupos hidrof?licos na superf?cie formados com o arrancamento de ?tomos de carbono. Para a atmosfera de nitrog?nio, tem-se a deposi??o de um filme com base em em grupos aminas. Tratamentos com a concentra??o pequena de Oxig?nio numa mistura com Nitrog?nio tem-se maior arrancamento de esp?cies das amostras

Cette thèse porte sur l’étude des écoulements de Taylor (ou poche/bouchon) gazliquide en microcanal. Ces écoulements où les effets de tension de surface sont prépondérants ont été étudiées expérimentalement et numériquement pour des géométries rectangulaires avec divers rapports d’aspects. Une première partie expérimentale a consisté à caractériser la formation de bulles (taille, fréquence) en fonction des conditions opératoires, des propriétés des fluides (notamment à travers le nombre capillaire) et du mode de mise en contact des fluides. La dynamique de l’écoulement établi a par la suite été étudiée à l’aide du code JADIM. La simulation de ces écoulements dominés par la tension de surface a nécessité de lever les limitations liées à la prise en compte de la force capillaire. En effet des courants parasites numériques sont créés à proximité de l’interface lors de la simulation d’écoulements capillaires. Une méthode Level Set a été implémentée et comparée à la méthode Volume of Fluid d’origine en termes de courants parasites. Des simulations numériques 3D ont permis l’étude des effets du nombre capillaire et de la géométrie sur la dynamique des bulles de Taylor (vitesse, pression et formes de bulles). Les effets inertiels souvent négligés ont été considérés et leur influence, notamment sur les sauts de pression à l’interface, a été mise en évidence. Le mélange dans le bouchon liquide a également été étudié. / This thesis focuses on the hydrodynamics of gas-liquid Taylor flow (or slug flow) in microchannels. These flows, which are generally dominated by surface tension forces, have been investigated in rectangular channels of various cross-sectional aspect ratios by means of both experimental visualizations and numerical simulations. The first experimental part aims at characterizing the bubble generation process (bubble length and frequency of break-up) depending on the operating conditions, the fluid properties, as well as the junction where both fluids merge. Numerical simulations of fully developed Taylor flow have been carried out with the JADIM code. The computation of such surface tension dominated flows requires an accurate calculation of the surface tension force. Some limitations of the Volume of Fluid method have been highlighted and a Level Set method has been developed in order to improve the calculation of capillary effects. Both methods have been compared in detail in terms of spurious currents. 3D numerical simulations have been performed and the influence of the capillary number, as well as the effects of geometry have been highlighted. Inertial effects have been taken into account and their influence on the pressure drop has been shown to be non-negligible. Mixing in the liquid slug has also been studied.

Made available in DSpace on 2015-05-14T12:14:08Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1022891 bytes, checksum: c086e09a9f99e06278f85a5575162e2b (MD5) Previous issue date: 2009-11-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Geometry, topology and elasticity are found in various branchs of physics and they play important roles in the understanding of many physical phenomena. In this work, we present three diferent systems where we can see such importance. First, a quantum neutral particle, constrained to move on a conical surface, is used as a toy model to explore bound states due to both a inverse squared distance potential and a delta-function potential, which appear naturally in the model due the geometry and topology of the cone. In the second one, we propose a method for probing the effects of curved 3-space by using materials with large coefficients of thermal expansion. Studying their fluctuations can be naturally cast in terms of a nonflat background geometry. In the last one, we determine the elastic-mediated interaction between colloidal nanoparticles adsorbed on the surface of free-standing smectic films. In contrast with the short-range character of the elastic- mediated force between particles adsorbed on smectic films supported by a solid substrate, the effective force acquires a long-range character in free-standing films, thus playing an important role in the formation of self-assembly structures in these systems. / A geometria, topologia e elasticidade estão presentes em vários ramos da física, e desempemham papel fundamental no entendimento de vários fenômenos físicos. Nesse trabalho, apresentamos três sistemas distintos onde podemos ver esse papéis. No primeiro, uma partícula quântica neutra confinada a mover-se em uma superfície cônica é usada como modelo para explorar estados ligados devido a um potencial proporcional ao inverso do quadrado da distância e devido a um potencial tipo delta. Ambos potenciais aparecem naturalmente devido a geometria e topologia do cone. No segundo, propomos um método de sondar os efeitos de um espaço curvo tridimensional usando materiais de grande coeficiente de expansão térmica. Neste caso, os três ingredientes citados acima são importantes para o entendimento do problema. Por fim, determinamos a interação entre nanocolóides adsorvidos na superfície de um filme esmético livremente suspenso. Essa interação é mediada por deformações elásticas no filme esmético; ela é de longo alcance, o que é importante para a formação de estruturas coloidais auto organizadas na superfície de tal filme.

Thesis submitted in fulfilment of the requirements for the degree DOCTOR TECHNOLOGIAE: ENGINEERING: CHEMICAL in the FACULTY OF ENGINEERING at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY 2014 / Several authors have reported on the use of alcohols – water /or mixed solvents to synthesise metal oxide nanoparticles. However, no systematic study has been carried out to evaluate the effect of mixed solvent on the particle characteristics, although considerable research has been reported, a gap still exists with regard to the effect of the alcohols as solvents on the growth kinetics of nanoparticles. To address these issues, four different alcohols, namely, methanol (MeOH), ethanol (EtOH), propanol (PrOH) and butanol (BuOH) were used as solvents in the synthesis of β-FeOOH particles. The effect of organic solvents on the growth kinetics of β-FeOOH nanorods has been evaluated for the first time in this study. Two-stage growth of akaganeite nanorods has been observed in BuOH and PrOH. The first growth stage follows a typical power law representing Ostwald ripening (OR) kinetic. The second stage was found to be asymptotic and obeyed oriented attachment (OA) kinetic. The proof of the OA kinetic also comes from the HRTEM images of the synthesised particles. Simultaneous occurrence of the two mechanisms was observed in the growth of the particles synthesised in EtOH and MeOH. The rate constants for OR kinetic, KOR, was found to be higher than the rate constant for OA kinetic, KOA, for different solvents used. Preamble The use of a mixed solvent is a new approach in the synthesis and processing of materials. Various researchers have stated that the surface tension of the solvent plays an important role in the formation of uniform nanorods. However, the effect of surface tension was not correlated with the particle growth, earlier, though the dielectric properties of the mixed solvents were only taken into account. Additionally, no quantitative or qualitative relationship was presented between surface tension and particle growth in the literature. In this work an attempt to correlate these two parameters (surface tension and particle growth) with the concentration of the precursor and temperature was made, resulting in an exponential relationship between KOR for the particle growth and surface tension of the alcohols. Furthermore, the relationship between surface tension and particle growth was validated by an independent study using statistically designed experiments to account for the influence of various process variables on the particle growth. The findings in this study obtained from both theoretical and experimental work provides an insight into the relationship between solvent surface tension and particle growth interactions, producing a new piece of information that will further promote our understanding of the formation mechanisms of β- FeOOH growth. The transformation temperature of akaganeite (β-FeOOH) nanorods to hematite (α-Fe2O3) particles was found to be solvent dependent. Thermogravimetric analysis and differential scanning calorimetry were performed to evaluate the effect of alcohol on the thermodynamic stability of the particles. Alcohol as solvent played a significant role in the dehydration property of the synthesised particles. The percentage mass loss of the particles at 300°C decreases linearly with increasing carbon number in the linear alkyl chain of the solvent. The effect of alcohol type on the particle morphology was found to be more pronounced at higher FeCl3 concentrations (>0.5M). Splitting of β-FeOOH nanorods was observed at FeCl3 concentration of 0.7M in BuOH. In PrOH, rectangular morphologies were obtained whereas nanoribbons resulted in surfactant-free conditions. It was found that the nature of anions (chloride vs. nitrate and sulphate) in the precursor salt also influenced the morphology.