Sol-Gel

Tungsten, silver and tungsten/silver co-doped titania nanopowders were synthesised via an aqueous sol–gel method. The size distribution and zeta potential of the starting sols were determined via photon correlation spectroscopy (PCS). The dried gels were thermally treated at two different temperatures, and the occurrence of amorphous phase was assessed using the combined Rietveld–RIR X-ray powder diffraction method. A systematic study of the optical properties of the powders was made with diffuse reflectance spectroscopy (DRS), and the energy band gaps were calculated using the differential reflectance method; while their morphology was investigated using electron microscopy analysis (TEM). The photocatalytic activity of the samples was assessed in liquid–solid phase, under UVA-light and visible-light irradiation, monitoring the degradation of an organic dye. The influence of the phase composition, optical properties, dimensions, and specific surface area of the powders on the photocatalytic activity was thoroughly discussed.

A B S T R A C T Luminescent-magnetic bifunctional Mn 2+-doped Zn 2 SiO 4 (ZSMn 2+) nanophosphor were synthesized by the sol-gel technique and characterized by X-ray diffraction (XRD), UV–vis absorption, transmission electron microscopy (TEM), photoluminescence (PL) and SQUID. The Mn 2+-doped effects of zinc silicate (ZS) upon the emission intensity and decay time were investigated under 4.86 eV excitation. Mn 2+-doped ZS nanopho-sphor exhibits predominant visible emission under 4.86 eV ultraviolet light excitation, and the trend of their color changes from green to yellow are simultaneously realized in single-phase. The ZS nanophosphors exhibit green and yellow luminescence, depending on their crystal structure, which can vary with the preparation conditions. The green peak at at 2.37 eV is due to α– phase, while the yellow peak centered at 2.15 eV is due to the β– phase. The two phases are diamagnetic at room temperature but become ferromagnetic at 5 K. It was found that α-ZSMn 2+ phase has a higher saturation than the β-ZSMn 2+ phase. The correlation between the optical, structural and magnetic properties of nanophosphor is discussed in detail.

Sol-gel glasses in quaternary silica–sodium–calcium–phosphorous systems have been synthesized using a rotary evaporator for rapid drying without ageing. This novel fast drying method drastically decreases the total drying and ageing time from several weeks to only 1 hour, thus overcoming a serious drawback in sol-gel preparation procedures for bioglasses. This work investigates the bioactivity behavior of two glasses synthesized by this fast method, with Ca:P ratios of 1.5 and 1.67. X-ray diffraction (XRD), Inductive coupled plasma, Fourier-transform infrared, and Raman spectroscopy were used to confirm the bioactivity of the synthesized powders. MAS-NMR was also used to assess the degree of silica polymerization. The composition with a higher Ca:P = 1.67 ratio showed better bioactivity in comparison to the one with Ca:P = 1.5, which exhibited little bio-response with up to 4 weeks of immersion in SBF (simulated body fluid). It was also found that an orbital agitation rate of 120 rpm favors the interfacial bio-mineralization reactions, promoting the formation of a crystalline hydroxyapatite (HAp) layer at the surface of the (Ca:P = 1.67) composition after 2 weeks immersion in SBF.
J Biomed Mater Res Part A: 106: 510–520 (2018).

Periodic mesoporous organosilica nanorods and nanospheres are synthesized from 1,4-bis(triethoxysilyl)ethylene and bis(3-ethoxysilylpropyl)disulfide. The nanosystems present the long-range order of the hexagonal nanostructure. They are degraded in simulated physiological conditions. The loading and release of doxorubicin with these nanosystems are both pH dependent. These nanoparticles are endocytosed by breast cancer cells and are very efficient for doxorubicin delivery in these cells.

We have developed an innovative, rapid sol-gel method of producing hydroxyapatite nanopowders that avoids the conventional lengthy ageing and drying processes (over a week), being 200 times quicker in comparison to conventional aqueous sol-gel preparation, and 50 times quicker than ethanol based sol-gel synthesis. Two different sets of experimental conditions, in terms of pH value (5.5 and 7.5), synthesis temperature (45 and 90 °C), drying temperature (60 and 80 °C) and calcination temperature (400 and 700 °C) were explored. The products were characterised by X-ray diffraction (XRD) Fourier-transform infrared spectroscopy (FTIR), scanning electron mi-croscopy (SEM) and specific surface area (SSA) measurements. Pure hydroxyapatite (Ca10(PO4)6(OH)2 , HAp) was obtained for the powders synthesised at pH 7.5 and calcined at 400 °C, while biphasic mixtures of HAp/β-tricalcium phosphate (β-Ca3(PO4)2 , TCP) were produced at pH 5.5 and (pH 7.5 at elevated temperature). The novel rapid drying was up to 200 times faster than conventional drying, only needing 1 h with no prior ageing step, and favoured the formation of smaller/finer nanopowders, while producing pure HAp or phase mixtures virtually identical to those obtained from the slow conventional drying method, despite the absence of a slow ageing process. The products of this novel rapid process were actually shown to have smaller crystallite sizes and larger SSA, which should result in increased bioactivity.

This work attempted to fabricate superhydrophobic fabric via a simple immersion technique.
Textile fabrics were coated with silica nanoparticles prepared from tetraethoxysilane (TEOS) to
obtain sufficient roughness with hydrophobic surface chemistry. Then, the coated fabrics were treated
with polydimethylsiloxane (PDMS) and aminopropyltriethoxysilane (APTES) to reduce the surface
energy. The effects of the PDMS concentration on the surface morphology and superhydrophobicity
of as-prepared fabric were investigated. The morphology and the composition of superhydrophobic
fabric were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDS),
and Fourier transform infrared (FTIR) spectroscopy. The results revealed the formation of spherical
silica nanoparticles with an average particle size of 250 nm throughout the fabric surface. The
possible interactions between silica nanoparticles and APTES, as well as the fabrics, were elucidated.
Investigating the hydrophobicity of fabrics via water contact angle (WCA) measurement showed
that the treated fabric exhibits excellent water repellency with a water contact angle as high as 151
and a very low water sliding angle. It was also found that the treated fabric maintained most of its
hydrophobicity against repeated washing, as the WCA of superhydrophobic fabrics decreased to
141 after 25 repeated washing cycles. The comfort properties of the obtained superhydrophobic
fabrics in terms of air permeability and bending length did not reveal any significant changes.

A novel, facile method based on a non-aqueous sol–gel solvothermal process has been developed to synthesise spherical TiO2 nanoparticles (NPs) in one pot. The reaction between titanium(IV) tert-butoxide (Ti[OC(CH3)3]4) and benzyl alcohol was a simple process, which resulted in the formation of highly crystalline titania NPs with a small size of only 6 nm, and with a correspondingly high surface area. The chemical formation mechanism of the metal oxide NPs has been proposed, and the degree of surface hydroxyls (–OH groups) has been examined. The products of the synthesis were characterised by X-ray powder diffraction (XRPD) using the advanced whole powder pattern modelling (WPPM) method, high-resolution transmission electron microscopy (HR-TEM), thermo-gravimetric analysis (TGA), UV-visible diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) spectroscopy. The photocatalytic activity (PCA) was evaluated in both the liquid–solid phase, by monitoring the degradation of an organic dye (methylene blue (MB)) under UV-light irradiation, and in the gas–solid phase, by following the degradation of 2-propanol under UV-and visible-light exposures. The synthesized titania powders not only exhibited excellent photocatalysis in the liquid–solid phase (under UV irradiation), but also possessed a superior PCA in the gas–solid phase under a visible-light exposure. The effects on the PCA of the very small crystalline domain size, surface composition and the presence of organic molecules due to the synthesis process of the TiO2 NPs were shown to account for this behaviour.

In this work, fabrication and characterization of a single-mode vinyltriethoxysilane (VTES) based hybrid organic-inorganic sol-gel ridge waveguide is reported. VTES based hybrid sol-gel material has been deposited by multiple spin-coating process on quartz substrate. Channel waveguides have been fabricated by UV photopolymerization followed by wet etching process. Optical guided mode was observed to ensure the single mode condition while cut-back technique was performed for loss propagation measurement. Optical propagation losses were measured to be 1.6 dB/cm at 1.31 μm wavelength. This value shows that this material is a promising choice for the development of integrated optical circuits for telecommunication field.

Novel quaternary (67Si-24Ca-10Na-8P) glass powders were successfully synthesised by sol-gel followed by two alternative drying schedules, conventional drying (CD) and an innovative fast drying (FD) process (200 times quicker). The glasses were thermally stabilised at 550 °C, and then characterised by different complementary techniques. The samples showed very similar silica network structures, with the FD one having slightly lower degree of polymerisation than the CD sample. This less polymerised, more open, network structure exhibited an improved bioactivity in simulated body fluid (SBF), probably also due to the apparent presence of poorly crystalline HAp in the stabilised glass powder. In contrast, the CD glass exhibited an unwanted secondary crystalline silica phase. Both glasses showed excellent biomineralisation upon immersion in SBF, being more pronounced in the case of FD with clear evidence of HAp formation after 4 h, while equivalent signs in the CD samples were only noticed after longer immersion periods between 8 h and 1 week.

Multicomponent oxide powders with nominal compositions of (45 − x)·SiO 2 ·24.5CaO·24.5Na 2 O·6P 2 O 5 xFe 2 O 3 (in wt.%) were prepared by a modified sol–gel procedure. X-ray diffraction (XRD) patterns and high resolution transmission electron microscope images of the sol–gel products show fully amorphous structure for Fe 2 O 3 substitutions up to 2 wt.%. Sol–gel derived 43SiO 2 ·24.5CaO·24.5Na 2 O·6P 2 O 5 ·2Fe 2 O 3 glass (or bioglass 45S5 with SiO 2 substituted with 2 wt.% Fe 2 O 3), exhibited magnetic behavior with a coercive field of 21 Oe, hysteresis loop area of 33.25 erg/g and saturation magnetization of 0.66 emu/g at an applied field of 15 kOe at room temperature. XRD pattern of this glass annealed at 850 °C for 1 h revealed the formation of a glass–ceramic containing sodium calcium silicate and magnetite phases in nanocrystalline form. Temperature dependent magnetization and room temperature electron spin resonance data have been used to obtain information on the magnetic phase and distribution of iron ions in the sol–gel glass and glass–ceramic samples. Sol–gel derived glass and glass–ceramic exhibit in-vitro bioactivity by forming a hydroxyapatite surface layer under simulated physiological conditions and their bio-response is superior to their melt quenched bulk counterparts. This new form of magnetic bioglass and bioglass ceramics opens up new and more effective biomedical applications.

Stainless steels are widely used in engineering activities due to its chemical and mechanical features that offer high corrosion resistance as well as a good relationship of mechanical strength, resistance to high temperatures. Several methods known in surface engineering can be used to optimize the properties against corrosion of this kind material. The coating adhesion mechanism is a chemical anchor, which can provide the necessary protection for steel and used in various industrial and construction applications. This work displays the evaluation of performance against corrosion at high temperatures of a steel 316L with oxide coatings Ti-Zr-Si deposited by sol gel, which allows obtaining a ceramic system, deposited and analyzed with a mono, bi and tri-layer architecture presenting the results for each of them, carried out an analysis of loss of weight, chemical composition by energy dispersive X-ray (EDS) and scanning electron microscopy (SEM). The coating tri-layer 10/70/20 showed better corrosion protection at high temperatures, less cracking and roughness changes.

In this paper, we report the comparison between nanosized TiO2 powders prepared via two different acidic conditions (i) pH2 (ii) pH4. The study presents the synthesis of nanosized TiO2 powder with anatase structure was derived from sol-gel process. Data concerning the effect of pH towards the development of TiO2 nanoparticles is reported. The samples were examined by SEM- EDAX, XRD, and FT-IR analysis. Surface morphological studies obtained from SEM micrograph. The Crystalline size of TiO2 powder has obtained for (i) pH 2 is ~3nm (ii) pH 4 is ~ 6nm at 400 ºC by controlling the acidity. In FT-IR, all the peaks observed were around 460-560 cm-1 due to stretching and bending vibrations of -OH groups. It was also found the pH of the solution affect the agglomeration of the particles

Novel nanocomposite adsorbent materials were synthesized by condensation polymerization of TEOS in the presence of saponified guar-graft-poly(acrylonitrile) (SG) as template. The effect of changing the molecular size of SG on the final properties of the composite materials was investigated in this paper. The composites were thermally treated at temperatures ranging from 80 to 1100 °C, to obtain materials of different performance. The chemical, structural and textural characteristics of the composites were determined by FTIR, XRD, TGA-DSC and SEM studies. Their adsorption properties were monitored in terms of Zn (II) binding capacity which could be tailored by changing the template size and sintering temperature. The adsorption capacity of the composite at room temperature was enhanced five times when thermally treated at 900 °C with a maximum adsorption of 3.58 meq/g of the zinc (II). The adsorption could be further optimized to higher values and the materials could be successfully recycled for three consecutive cycles without any significant loss in the adsorption capacity.

For the first time, sodium cobalt oxide (NaxCo2O4) crystalline thermoelectric materials were obtained using polyvinyl alcohol (PVA) polymerized complex sol-gel solution. PVA was used as polymer solution with sodium acetate/cobalt acetate, followed by calcination at 800oC. The sodium cobalt oxide calcined crystal structures were characterized by X-ray diffraction (XRD). The sol-gel solution calcined at 800oC and then sintered at the same temperature was single crystal and XRD results have an agreement with the literature values. The results indicated that the polymeric sol-gel method is a promising process for the synthesis of sodium cobalt oxide thermoelectric materials.

Synthesis of sol-gel glass with incorporation of Na2O is extremely difficult, as such glasses have a great tendency to crystallize. Slow drying and aging over several days or weeks is usually required in sol-gel preparation procedures. This work reports a fast, novel route for the synthesis of bioglass powders in a considerably shortened period of 1 h. A comparative study of sol-gel derived glasses made by this novel route using rotary evaporator drying, and a conventional route using oven drying and aging, revealed that the two methods produce stabilized (devitrified) bio-glasses with virtually identical behavior and properties. Indeed, the rapidly dried powder exhibited slightly enhanced properties that should result in improved bioactivity. Fourier-transform infrared spectroscopy was used to understand the structures of the synthesized powders, and MAS-NMR was used to look at the degree of polymerization. This innovative, rapid route was successfully demonstrated to produce glass and devitrified glass nanopowders more than one hundred times quicker than the quickest reported standard drying methods.

The influence of two divalent cations, Cu2+ and Mn2+ , on the structure, sintering, and crystallization of glasses and glass-ceramics in the diopside–calcium pyrophosphate system (90 wt.% diopside (CaMgSi2O6), 10 wt.% calcium pyrophos-phate (Ca2P2O7)) was investigated. Glasses with 1, 3, and 5 wt% MnO or CuO additives were prepared by melt-quenching and characterized by XRD, 29 Si and 31 P NMR, DTA, and FTIR This revealed that the silicate network is predominantly coordinated in Q2 (Si) units for all glasses, while phosphorus tends to inhabit an orthophosphate (Q0) environment. All glasses had a high rate of bioactivity after immersion in simulated body fluid. A slight depolymerization was observed in the doped glasses leading to lower Tg values in comparison with the parent glass. All glass-ceramics exhibited the formation of diopside as the primary crystalline phase after sintering at 850 °C/1 h. In comparison with the parent glass, the doped glasses featured significantly larger processing windows (ΔT = Tc –Tg), ensuring good sinterability. Further, with increasing doping levels, the glasses exhibited a gradual decrease in T p and ΔT, suggesting an increased tendency toward devitrification. All Cu-and Mn-containing glasses exhibited the formation of hydroxyapatite, making them good candidates for biomedical applications and tissue engineering.

Aligned fibres of partially stabilised zirconia (PSZ, 4 mol% Y2O3) and fully stabilised zirconia (FSZ, 8 mol% Y2O3), 3-5 μm in diameter, were blow spun from a sol-gel precursor, and then fired to give the ceramic fibre. Various potential sol precursors were investigated and characterised, the optimum being an aqueous sol made from hydrolysed and peptised zirconium iso-propoxide. The resulting zirconia fibres were characterised and their evolution studied by XRD, DTA/TGA and SEM, and their mechanical properties assessed. It was found that both PSZ and FSZ fibres formed poorly crystalline cubic zirconia at only 200°C, which became fully crystalline after firing to 400°C. The cubic form was the only phase seen in the FSZ fibre, whereas the PSZ fibre formed the tetragonal phase after firing between 1000 and 1200°C/3 h, and all fibres were nanocrystalline (grain diameter<0.1 μm). Unusually the monoclinic form of zirconia was never observed in the PSZ fibres. After firing above 1200°C the fibres had a strain to break of 0.59%, and appeared to be well sintered from shrinkage data. They had superior creep resistance to Saffil zirconia fibres, creeping at temperatures 50°C higher.

Iron oxides nanoparticles with different sizes are successfully synthesized using sol-gel
method. X-ray diffraction (XRD) and Mössbauer spectroscopy show that the obtained
nanoparticles are mainly composed of maghemite phase (
-Fe2O3). XRD and transmission
electron microscopy (TEM) results suggest that the nanoparticles have sizes ranging from 14
to 30 nm, which are indeed confirmed by large magnetic saturation and high blocking
temperature. At room temperature, the observation of a non-negligible coercive field suggests
2
that the particles are ferro/ferrimagnetic. The specific absorption rate (SAR) under an
alternating magnetic field is investigated as a function of size, frequency and amplitude of the
applied magnetic field. A mean heating efficiency of 30 W/g is obtained for the smallest
particles at 110 kHz and 190 Oe, whereas further increase of particle size does not improve
significantly the heating efficiency.

In this study, 10 mol% ZrO 2 was added to a 27CaO–5P 2 O 5 –68SiO 2 (mol%) base composition synthesized via a simple sol–gel method. This composition is similar to that of a frequently investigated bioactive gel–glass. The effects of ZrO 2 on the in vitro bioactivity and MG-63 cell proliferation of the glass and its derivative polycrystalline (glass–ceramic) powder were investigated. The samples were characterized using thermo-gravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled to energy dispersive X-ray spectroscopy (EDS). Release of Si, Ca, P and Zr into simulated body fluid (SBF) was determined by inductively coupled plasma (ICP). Upon heat treatment at 1000 °C, the glass powder crystallized into an apatite–wollastonite–zirconia glass–ceramic powder. Hydroxycarbonate apatite (HCA) formation on the surface of the glass and glass–ceramic particles containing ZrO 2 was confirmed by FTIR and SEM. Addition of ZrO 2 to the base glass composition decreased the rate of HCA formation in vitro from one day to three days, and hence, ZrO 2 could be employed to control the rate of apatite formation. However, the rate of HCA formation on the glass–ceramic powder containing ZrO 2 crystal was equal to that in the base glassy powder. Tests with a cultured human osteoblast-like MG-63 cells revealed that the glass and glass–ceramic materials stimulated cell proliferation, indicating that they are biocompatible and are not cytotoxic in vitro. Moreover, zirconia clearly increased osteoblast proliferation over that of the Zr-free samples. This increase is likely associated with the lower solubility of these samples and, consequently, a smaller variation in the media pH. Despite the low solubility of these materials, bioactivity was maintained, indicating that these glassy and polycrystalline powders are potential candidates for bone graft substitutes and bone cements with the special feature of radiopacity.

Achieving advanced multifunctional materials displaying several coexisting properties is currently one of the most exciting and innovative research topics. In this study, we report the engineering of a multifunctional material exhibiting, at the same time, tuneable photochromic behaviour and gas-sensing properties for acetone detection. The photochromic property of silver modified (1–10 mol% Ag) titanium dioxide (titania, TiO2) NPs was monitored under consecutive UVA-light exposure times, and the change in colour was thoroughly investigated with both spectroscopic and colourimetric analyses. All Ag modified samples exhibited a significant change in colour and visible spectra after only 15 seconds of exposure, and this increased with further exposure. It was shown that both the silver molar content in the Ag–TiO2 nano-heterostructure, as well as the UVA-light irradiation time, governed the tunability of the photochromic behaviour (the colour changed from pale yellow to dark blue in Ag-modified specimens, while it remained white in unmodified TiO2). The same nano-heterostructures were also tested as sensing materials for resistive metal oxide gas sensors (MOS). These Ag–TiO2 nano-heterostructures proved to be highly sensitive for the detection of acetone vapours at low concentrations (<1 ppm), superior to the best TiO2-based sensors so far reported. This is the first thorough study to qualitatively monitor, in real-time, the growth of Ag0 NPs on a TiO2 matrix, assessing both optical spectroscopy and colourimetric CIEL*a*b* analysis (e.g. what meets the eye), and to also demonstrate the superior acetone gas-sensing properties of such nano-heterostructures.

The effects of three functional ions (yttrium Y 3+ , fluorine F − , titanium Ti 4+) on the glass forming ability, sintering, crystallization, and thermo-physical properties of glasses and glass-ceramics were studied in a diopside–calcium pyrophosphate (90% CaMgSi 2 O 6 –10% Ca 2 P 2 O 7) system. Three different percentages (1, 3 and 5 wt%) for each additive were tested. The structural features of glasses were assessed through FT-IR (Fourier Transform infra-red spectroscopy) and 29 Si and 31 P NMR (nuclear magnetic resonance), showing that the silicate network in all the investigated glasses is predominantly coordinated in Q 2 (Si) units, while phosphorus tends to remain in the orthophosphate (Q 0) environment. All glasses exhibited fast rates of biomineralization, making them promising candidates for biomedical applications. The sintering and crystallization behaviours of the glass powders were studied by differential thermal analysis (DTA), while the coefficient of thermal expansion (CTE) was determined by dilatometry. Glass transition temperature (T g) values of all doped glasses were lower than the parent glass, while CTE values decreased with initial addition (1 wt%), of dopants before exhibiting an increase with further addition. In Y-doped glasses, a gradual increase was seen in the values of maximum crys-tallization peak temperature, T p , up to 3 wt%, while an opposite trend was observed in Ti-doped glasses, showing an enhancement of the stability of the Y-doped glasses against devitrification. F-doped glasses exhibited a similar trend. Crystalline phase evolution was analysed by X-ray diffraction (XRD), and amorphous glass were obtained by sintering powder compacts from all the glasses at 800 °C for 1 h.

Titania hydrolysates prepared from the hydrolysis of both unmodified and modified tetraisopropoxytitanium(iv) are shown by both FT-Raman spectroscopy and X-ray diffraction to be amorphous with no long range ordering. The Raman hydrolysate spectra show three broad bands, consisting of multiple components, at Raman shifts of ∼210, 440 and 570 cm−1. These bands do not correspond with any known phase of titania. Thermal analysis shows broad endothermic peaks centred at 106–136°C and extending to ≥200°C for each of the hydrolysates and is attributed to dehydration and loss of water. Strong, broad exothermic peaks are observed in the modified hydrolysate curves, in the 310–340°C temperature range and are attributed to the combustion of the residual surface adsorbed organics. Weight loss occurred during these exotherms. Crystallisation of the disordered hydrolysates into anatase occurs in the 500–600°C temperature range. The anatase → rutile phase transition was found between 665°C and 691°C.

In this study, different samples of Si and Sr co-doped TiO2 thin films (5mol% Si and 5-10-15-20mol% Sr) were prepared via simple sol.gel synthesis method by using strontium acetate as strontium precursor, Tetraethoxysilane as silicon precursor, and titanium (IV) isopropoxide (TTIP) as titanium precursor. The effects of co-doping process on the structural, optical, and wettability properties of thin films were studied by X-ray diffraction (XRD), Scanning electron microscope (SEM) and contact angle measurement. XRD results showed that, the anatase phase formation was promoted by Si+4 and Sr+2 co-doped samples at higher percentage of Sr.Accordingly, the titania thin films showed various water contact angles, the water contact angles first decreased from 55.2 to 8.1¢ª then increased to 40.70 by changing the content of Sr doped.

Amongst nanomaterials, metal oxides play an increasingly dominant role, with titanium dioxide (titania, TiO2) being widely used for various applications, such as light-to-energy conversion and storage, and photocatalysis. In this work, TiO2 has been synthesised via an aqueous sol–gel method, using three different mineral acids (HNO 3 , HCl and HBr) to peptise the sol, and hence provide counter-ions. Dried sols were thermally treated at three different temperatures (450, 600 and 800 °C), using three different dwell times (2, 4, and 8 h). Advanced X-ray methods were used to monitor the effect that the counter-ions had on the anatase-to-rutile phase transformation (ART). Quantitative phase analysis (QPA) using the Rietveld method was applied to assess the true amount of crystalline phases in the systems, and the amount of amorphous phase. Furthermore, the average crystalline domain diameter was also investigated, using whole powder pattern modelling (WPPM). With the advanced XRPD data (actual crystalline phase weight fraction in the samples and their average domain diameter and size distribution), it was possible to carry out a semi-quantitative study of the ART transformation kinetics. At a low temperature of 75 °C, the Cl − counter-ion was the most favourable to obtain anatase as the major crystalline phase, delaying the onset of the ART. Conversely, the Br − ions, maintained more anatase at 450 °C, with a lower ART rate. In general, halides were more effective in delaying the ART than NO3 − counterions. Moreover, we observed an inverse linear relationship between the lattice volume expansion of rutile and the increase of its crystalline domain size at 450 and 600 °C isotherms. As the domain sizes increased with temperature, this effect reversed and became a direct linear dependence at the 800 °C isotherm, suggesting a critical size limit <90 nm for this effect.