Silanization Process Research Articles

Which is better? Experimental and simulation analyses of the chemical modification of carbon nanotubes to improve their dispersion in water

This work combines molecular dynamics with experimental results to explain the behavior of the two main functionalization alternatives of carbon nanotubes (acidification and silanization) when they are dispersed in water. It was observed that the presence of carboxyl and hydroxyl groups in the carbon nanotubes improves the interaction with the aqueous medium by 22% in comparison with the pristine and silanized material. This indicates that the process of acidifying carbon nanotubes to improve their dispersion in aqueous systems is preferable and it is not necessary to employ an additional silanization stage. Experimental studies show that the silanization process induces partial stability because of the positive charges on the surface material, whereas the acidified system is stable for up to 24 hours. On the one hand, pristine and silanized nanotubes show the formation and rupture of the agglomerates; on the other hand, the acidified system shows a behavior similar from that of water, since appropriate interactions occur between the nanotubes and the water molecules. Computational studies were used to evaluate the performance of the systems by calculating the diffusion coefficient and the potential energy of the system. The energy of the system relates to intermolecular interactions between the species involved; greater intermolecular forces guarantee a better integration of the nanotubes, since the forces do not represent an impediment either for the medium to flow or for the nanomaterial to diffuse within the medium. In addition, the distribution of the charge on the surface of the carbon nanotubes guarantees repulsion between them, improving colloidal stability.

Use of Target-Specific Liposome and Magnetic Nanoparticle Conjugation for the Amplified Detection of Norovirus.

Viral diseases are one of the most life-threatening diseases as they can erupt unpredictably and spread rapidly in any medium with a very small number of particles. Therefore, the key for lethal virus detection should be highly sensitive in the early-stage detection, which can help increase the chance of survival. Amplification of the detecting signal is one of the most promising mechanisms for the detection of low-concentration analytes. A proper amplification can develop such a kind of system where a small number of particles can produce intense signals for a prominent detection. Keeping this in mind, in this report, we have presented a fluorometric method to detect norovirus (NoV) by a newly developed fluorophore-labeled liposome and a magnetically modified Fe3O4 combined system. Homogeneously distributed amine-functionalized liposomes have been constructed filled with a strong fluorophore of calcein. Simultaneously, (3-aminopropyl)-triethoxysilane (APTES)-functionalized Fe3O4 nanoparticles are also synthesized by the standard silanization process, and these two separately synthesized nanoparticles were functionalized with an antibody to achieve specificity. The Fe3O4 and calcein-liposome system has been applied for NoV detection, which was magnetically separated from the analyte medium and then externally burst to release the fluorophores from the core of the liposome. The easiness, rapidity, and sensitivity in a wide linear range can offer a huge potential of this method in point-of-care diagnostics.

Cobalt oxide encapsulated hydrophilic hierarchical Silicalite-1 for highly efficient conversion of cyclohexyl hydroperoxide

Abstract CHHP is the main product of the cyclohexane oxidation process, the rational design and preparation of solid catalysts are vital important for the development of an environmental benign CHHP conversion process. Herein, cobalt oxide encapsulated hydrophilic hierarchical Silicalite-1 was developed for CHHP conversion. In the presence of an organosilane, the encapsulation of cobalt oxide, creation of intracrystalline secondary porosity, and introduction of surface silanols were simultaneously achieved via hydrothermal synthesis. The particle size of the encapsulated cobalt oxide was about 4.7–6.3 nm, while the SBET, VT and VME are 527 m2/g, 0.417 cm3/g and 0.3 cm3/g, respectively. Moreover, the SBET further increases to 692 m2/g when the silanization process was intensified by surfactants, and the hydrophilic substrates could more easily be adsorbed by the catalyst for the abundant terminal silanols. Then, the dilute CHHP could selectively be adsorbed and activated by the catalyst, and a CHHP conversion of more than 99% could be achieved in 20min. More importantly, the catalyst exhibits outstanding activity in both the CHHP decomposition reactions and cyclohexane oxidation reaction with CHHP as the oxidant, the oxygen utilization efficiency (60%) and KA oil selectivity (120%) were notably improved. The stability of the catalyst is excellent, the activity retained after recycling for 20 times. This strategy is general, which could further be applied for the development of heterogeneous catalysts for more environmental benign chemical processes.

Aluminium Interdigitated Electrode Based Biosensor for Specific ssDNA Target Listeria Detection

Nowadays interdigitated electrode (IDE) based sensor have stimulated increasing interest in the application of biosensor filed. A large number of finger electrodes as comb structure gain high sensitivity through electrical measurements. In this paper, we have investigated Listeria bacteria detection through the electrical based IDE. Listeria monocytogenes is a food borne pathogen-based bacterium that can cause dangerous disease to human, some infection may result in death. The AutoCAD software was used to design the chrome mask of IDE sensor and the fabrication process was done using conventional photolithography method. The fabricated Al IDE morphologically analyzed using a low power microscope (LPM), a high-power microscope (HPM) and 3D profiler. Functionalization step of the Al IDE, silanization process was done using (3-Aminopropyl) triethoxysilane (APTES), immobilization process was done using carboxylic probe Listeria and Tween-20 as a blocking agent for nonspecific binding on the non-immobilized area of the biosensor surface. The biosensor was validated with complementary, non-complementary and single base mismatch ssDNA targets. Different concentration of complementary ssDNA target from 1 fM to 1 µM was done for the sensitivity detection.

Enhancement of carbonate apatite scaffold properties with surface treatment and alginate and gelatine coating

Carbonate apatite (CO3Ap) scaffolding has been widely used for bone repair and replacement due to its excellent osteoconductivity and resorbability in bone defects. However, the application of the porous scaffold has been limited by its brittleness. Here, CO3Ap scaffolds coated with 1, 3 and 5 wt% of sodium alginate (SA) and bovine gelatine (BG) were fabricated to improve the mechanical properties of the porous scaffold. Limited studies have been done on a CO3Ap scaffold coated with a natural polymer layer. Here, a CO3Ap scaffold was fabricated through the phase transformation from β-tricalcium phosphate (β-TCP) to CO3Ap using a hydrothermal method. Fourier-transform infrared (FTIR) analysis confirmed the presence of both SA and BG functional groups on the CO3Ap scaffold. Five wt% of SA and BG improved the compressive strength of the uncoated CO3Ap scaffold by 34% and 46%, respectively. The SA coating was found to enhance the compressive strength of the CO3Ap scaffold compared to the BG coating due to its high viscosity. Furthermore, the compressive strength of the scaffold increased by 40% after undergoing a silanization process and being coated with SA. These results indicate that the use of a silane treatment improved the chemical bonding between the CO3Ap scaffold and SA coating. This process increased the adhesion between the SA coating and the scaffold and improved the compressive strength.

Magnetic Graphene Oxide Composite for the Microextraction and Determination of Benzophenones in Water Samples

Magnetite nanoparticles (Fe3O4) functionalized with graphene oxide (GO) have been synthesized through a silanization process of the magnetic nanoparticles with tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane and further coupling of GO. The synthesized nanomaterials have been characterized by several techniques, such as transmission electron microscopy (TEM), and infrared and Raman spectroscopy, which enabled the evaluation of the different steps of the functionalization process. The hybrid nanomaterial has been employed for the extraction of five benzophenones (benzophenone-1, benzophenone-3, 4-hydroxybenzophenone, benzophenone-6 and benzophenone-8) in aqueous samples by dispersive micro-solid phase extraction, combining the magnetic properties of magnetite nanoparticles with the excellent sorption capacity of graphene oxide via hydrophobic interactions with the analytes. The subsequent separation and quantification of the analytes was performed by liquid chromatography with tandem mass spectrometric detection, achieving limits of detection (LODs) in the range 2.5 to 8.2 μg·L−1, with relative standard deviations ranging from 1.3–9.8% and relative recovering in the range 86 to 105%. Positive swimming pool water samples analysed following the developed method revealed the presence of benzophenones in from 14.3 to 39 μg·L−1.

New biocomposite obtained using poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH) and microfibrillated cellulose

ABSTRACTThis research evaluates the effects of filler content and silanization on thermal, morphological and mechanical properties of poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH)‐based composites. Microfibrillated cellulose (MFC) was obtained by a mechanical treatment of high‐pressure homogenization, starting from oat hull fiber, a byproduct of the agri‐food sector. MFC reinforced PHBH composites were prepared by melt compounding. SEM and FT‐IR analysis showed a good dispersion of the filler in the polymeric matrix, denoting the effectiveness of the surface silanization process. The thermal stability of PHBH composites remains substantially unchanged, and the glass transition temperature marginally increases with the increase of the filler content. Furthermore, silanized MFC shows slightly reinforcing mechanical effects on PHBH composites, such as the increase of 10% of the Young modulus with an increase of the maximum tensile stress as well. This finding has an economical interest since the results showed that MFC, deriving from a byproduct, can be successfully used as filler, decreasing the cost of the bio‐based compound leaving substantially unaltered its mechanical and thermal properties. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48953.

Verifying the effect of silanized nitinol surface: An in-vitro study

Although Nitinol is a popular orthopedic implant material, there is still need of surface modification of nitinol to control nickel leaching. Main challenge with such surface modification of orthopedic implant is that along with cost effective modification the surface, there should be good integration with the surrounding bone tissue. In this study surface of the shape memory Nitinol was modified by simple silanization process using (3-aminopropyl)triethoxysaline(APTES). Here we report the interaction between the Nitinol surface (both bare and silanized) and the human osteoblastic cells (MG63cell) over a period of 48 hours. From detailed investigations, involving MTT assay and immunocytometry it was found that silanized Nitinol performed marginally better than bare Nitinol. The effect of silanization on surface composition and roughness of the specimen is also reported here to explain the superiority of silazised samples in case of cell-material interaction.

Effects of surface-modified pineapple fibre-reinforced micro B4C and CTBN rubber particle toughened epoxy hybrid composites in mechanical, impact damage, thermal and water absorption behavior

In this present work, the drop load impact damage, mechanical, thermal and water absorption behaviour of surface-modified pineapple fibre reinforced micro boron carbide (B4C) and carboxyl-terminated acrylonitrile butadiene (CTBN) rubber toughened epoxy composites are studied. The principal aim of this research is to unveil the effects of surface modification and the role of adding microparticles into the resin matrix. The natural fibre and microparticles were surface-treated by an amino silane (3-Aminopropyl)trimethoxysilane (APTMS). The silanization process was done in aqueous solution. The epoxy hybrid composites were prepared using hand lay method. The impact damage results revealed that addition of surface-modified CTBN micro rubber along with pineapple fibre and micro B4C improved the damage resistance. Similarly, the mechanical and thermal results revealed that additions of surface-modified B4C and CTBN rubber microparticles improved the tensile, flexural and Izod impact damage behaviour with better thermal stability. The contact angle of the hybrid composites showed a higher contact angle, which shows higher hydrophobicity. The fractography images showed improved bonding and effective dispersion of microparticles in the matrix. These mechanical, thermal and impact damage resistance composites are highly sought after in structural, hybrid vehicles and mini-aircraft applications.

Silica‐filled S‐SBR with epoxidized soybean oil: Influence of the mixing process on rheological and mechanical properties of the compound

ABSTRACTThe incorporation of epoxidized soybean oil (ESO) in a silica‐filled tread rubber was studied. The aim of this research is to determinate the influence of ESO addition stage on rheological, thermal, mechanical, and viscoelastic properties in the rubber compound. The results suggested that ESO may compete with the silanes in the reaction with silanol groups on the silica surface, interfering with the silanization process. Therefore, a series of ESO‐functionalized silica particles were prepared in which the ESO addition at different conditions were compared to the compound mixing conditions. The presence of covalent bonds by ESO onto silica surface and the changes originated by the silane incorporation were confirmed by Fourier‐transform infrared spectroscopy and thermogravimetric analysis. Consequently, it can be affirmed that the effect of reaction conditions and the sequence of silane/ESO mixing have a strong influence on the final properties of the rubber compound. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48504.

Cohesion-driven mixing and segregation of dry granular media

Granular segregation is a common, yet still puzzling, phenomenon encountered in many natural and engineering processes. Here, we experimentally investigate the effect of particles cohesion on segregation in dry monodisperse and bidisperse systems using a rotating drum mixer. Chemical silanization, glass surface functionalization via a Silane coupling agent, is used to produce cohesive dry glass particles. The cohesive force between the particles is controlled by varying the reaction duration of the silanization process, and is measured using an in-house device specifically designed for this study. The effects of the cohesive force on flow and segregation are then explored and discussed. For monosized particulate systems, while cohesionless particles perfectly mix when tumbled, highly cohesive particles segregate. For bidisperse mixtures of particles, an adequate cohesion-tuning reduces segregation and enhances mixing. Based on these results, a simple scheme is proposed to describe the system’s mixing behaviour with important implications for the control of segregation or mixing in particulate industrial processes.

Comparison of Various Chemical Treatments Efficiency in Relation to the Properties of Flax, Hemp Fibers and Cotton trichomes

ABSTRACT The main aim of this study was to chemically modify the plant fiber surface. Hemp, flax fibers and cotton trichomes were subject of surface treatments using silanization, acetylation, benzoylation, and mercerization processes. The fiber properties were evaluated with the use of fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), wide-angle X-ray analysis (WAXS) and thermogravimetric analysis (TGA). Additionally, humidity and color of the modified fibers were evaluated. Chemical treatment of the plant fibers reduced their hydrophilic nature, increased the moisture resistance, and improved their thermal stability. In all the cases the silanization process proved to be the most effective method of improving fiber thermal stability and moisture resistance, yet mercerization and benzoylation methods offered satisfying results as well.

Influence of Surface Treatment on the Interfacial and Mechanical Properties of Short S-Glass Fiber-Reinforced Dental Composites.

The influence of interfacial shear strength (IFSS) between processed short S-glass fibers (250 and 350 μm in length, 5 μm in diameter) and the dental resin (a mixture of urethane dimethacrylate and triethylene glycol dimethacrylate monomers) on the mechanical properties has been studied experimentally. The surface profile of short S-glass fibers was modified using a selective atomic level metal etching process and simple silanization process to enhance the interfacial properties. The S-glass fibers were etched in acid solutions to increase the surface roughness and selectively remove Al3+ and Mg2+ ions, which promoted the mechanical and chemical interfacial bonding reactions. The single glass fiber tensile and microdroplet pull-out tests were performed to investigate the effects of interfacial properties on the flexural strength of the resultant composites. The surface modified S-glass fibers showed an increase of 11-40% in IFSS compared to untreated glass fibers. Composites reinforced with 350 μm length glass fibers (AR-70), which were treated in piranha solution for 4 h, showed the highest improvement in overall mechanical properties, flexural strength (34.2%), modulus (9.7%), and breaking energy (51.9%), compared to the untreated fiber-reinforced composites. The modified Lewis-Nielsen equation was developed using the effective fiber length factor to accurately predict the modulus of the short fiber-reinforced composites and validated with experimental results.

The hydrophobicity modulation of glass and marble materials by different Si-based coatings

Hydrophobic polymers applied on hydroxylated surfaces increase their durability against undesired weathering processes. The achievement of a certain degree of surface hydrophobicity (reducing the water permeation) constitutes one of the main research focuses. Herein, two commercial Si-based resins (e.g. Alpha®SI30 and Bluesil®BP9710), directly applied on both glass and Carrara marble substrates, and a silanization process by using trichloromethylsilane (TCMS) were adopted. Contact angle measurements together with hysteresis determination and Surface Free Energy (SFE) were carried out to evaluate the hydrophobic features. Hence, since only in the case of TCMS a good hydrophobicity was achieved (θ around 150°), two commercial polysiloxane-based additives (e.g. TegoPhobe 1500 N and TegoPhobe 1650) were added respectively to Alpha®SI30 and Bluesil®BP9710, according to their chemical compatibility. These auxiliary substances allowed to decrease the wettability features of either glass or marble. Furthermore, since all the investigated coatings could be used as stone materials protective agents, water capillary absorption and vapor permeability tests were performed. Also in this case, TCMS revealed to be the most performing one among the adopted silane-based resins, thanks to the drastic reduction of absorbed water and the decrease of vapor permeability within the threshold value of 50%. Finally, the coatings stability was evaluated by accelerated ageing tests.

Natural rubber compositions with the partial/total replacement of carbon black/naphthenic oil by renewable additives: Rice husk ash and cashew nut oil

ABSTRACTThe aim of this work was to use additives from renewable sources to develop an elastomeric formulation with reduced environmental impact and lower rolling resistance. Twelve compositions containing various proportions of rice husk ash—RHA (20, 40, 60, 80, and 100 phr to replace carbon black [CB]) and a combination of RHA with CB (30CB/10RHA and 20CB/20RHA) using cashew nut oil (3 phr) as a processing aid were prepared and characterized based upon their rheometric and physical–mechanical properties. The combined use of CB and RHA after the silanization process (30CB/10RHAS) increased wet grip by 3.6%, reduced rolling resistance by 17.3%, and improved abrasion resistance by 7.3%. Therefore, the use of these alternative raw materials represents an important contribution for the technological development of rubber compounds, with a combination of durability, safety, economy, and reduction in CO2 emissions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48314.

Adhesion of electrosprayed chitosan coatings using silane surface chemistry

Biomedical implant devices for dental/craniofacial and orthopedic applications are a reliable and effective means for repairing/re-storing function of damaged, diseased or missing tissues. Electrospray coating technologies provide an additive manufacturing route to endow implant surfaces with properties to improve their performance by controlled deposition of desired materials, compounds and/or agents in the form of nano- or micro-particles on the surface of implant devices under relatively mild conditions. They provide a means to control the structure of coatings with high precision that allows the functionalization of complex 3D geometries of the implants with a range of desired physical and bioactive properties. Devices such as dental implants, total joint replacement devices, bone plates and screws that cannot be easily coated by other manufacturing methodologies such as solution casting, sputtering, or electrochemical treatments, can be robustly handled by the electrospray technique. This study focuses on assessing the adhesion of electrosprayed chitosan coatings on model titanium surfaces and screws to explore their potential as an implant treatment technology. To maximize the adhesion strength between the chitosan coating and a titanium surface, a tri-ethoxy-silylbutyraldhyde silane-based treatment is applied to chemically bond the coated chitosan to the substrate. Adhesion strength values are reported and compared between electrosprayed and solution cast chitosan coatings. For both methods, the role played by the silanation process is also explored. It is seen that silanation significantly improves the adhesion of the coatings, and electrosprayed, silanated coatings have a strength (5.87 MPa ± 2.03 MPa) that is comparable to solution-cast, silanated coatings (4.85 MPa ± 1.34 MPa) and offer control and flexibility as an additive manufacturing/coating process. We also, coat titanium screws and measure the loss of mass of chitosan coating during simulated surgery of screwing them into a polyurethane bone foam. The average loss of mass of chitosan is 34.3%, with most of it coming from the leading edge of the screw that experiences maximum shear during drilling. The merits and shortcomings of the electrospray for coating chitosan are discussed with possible improvements for future developments.

Dental Implants with Anti-Biofilm Properties: A Pilot Study for Developing a New Sericin-Based Coating.

Aim: several strategies have been tested in recent years to prevent bacterial colonization of dental implants. Sericin, one of the two main silk proteins, possesses relevant biological activities and also literature reports about its potential antibacterial properties, but results are discordant and not yet definitive. The aim of this study was to evaluate the effectiveness of different experimental protocols in order to obtain a sericin-based coating on medical grade titanium (Ti) able to reduce microbial adhesion to the dental implant surface. Materials and Methods: different strategies for covalent bonding of sericin to Ti were pursued throughout a multi-step procedure on Ti-6Al-4V disks. The surface of grade 5 Ti was initially immersed in NaOH solution to obtain the exposure of functional -OH groups. Two different silanization strategies were then tested using aminopropyltriethoxysilane (APTES). Eventually, the bonding between silanized Ti-6Al-4V and sericin was obtained with two different crosslinking processes: glutaraldehyde (GLU) or carbodiimide/N-Hydroxy-succinimide (EDC/NHS). Micro-morphological and compositional analyses were performed on the samples at each intermediate step to assess the most effective coating strategy able to optimize the silanization and bioconjugation processes. Microbiological tests on the coated Ti-6Al-4V disks were conducted in vitro using a standard biofilm producer strain of Staphylococcus aureus (ATCC 6538) to quantify the inhibition of microbial biofilm formation (anti-biofilm efficacy) at 24 hours. Results: both silanization techniques resulted in a significant increase of silicon (Si) on the Ti-6Al-4V surfaces etched with NaOH. Differences were found between GLU and EDC/NHS bioconjugation strategies in terms of composition, surface micro-morphology and anti-biofilm efficacy. Ti-6Al-4V samples coated with GLU-bound sericin after silanization obtained via vapor phase deposition proved that this technique is the most convenient and effective coating strategy, resulting in a bacterial inhibition of about 53% in respect to the uncoated Ti-6Al-4V disks. Conclusions: The coating with glutaraldehyde-bound sericin after silanization in the vapor phase showed promising bacterial inhibition values with a significant reduction of S. aureus biofilm. Further studies including higher number of replicates and more peri-implant-relevant microorganisms are needed to evaluate the applicability of this experimental protocol to dental implants.

Graphene and graphene oxide functionalisation with silanes for advanced dispersion and reinforcement of PMMA-based bone cements.

The reinforcement of PMMA bone cements using carbon based nanomaterials has demonstrated to be a potential solution to their poor mechanical properties. The achievement of an optimal dispersion of the nanoparticles within the polymeric matrix is a crucial but not easy stage in the production of high-quality reinforced materials. In this work, a useful route for the graphene (G) functionalisation, via silanisation with (3-methacryloxypropyl) trimethoxy silane (MPS), has been developed, providing a remarkable enhancement in dispersibility and mechanical properties. With the purpose to define the critical graphene surface oxidation parameters for an optimal silanisation, different routes were thoroughly analysed using infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results showed that the silanisation significantly improved the G dispersibility: whereas the pristine G dispersion fell down within the first 24 h, the silanised G showed an adequate stability after 5 days. Additionally, this improved dispersibility produced a notable increase in the mechanical properties of the G-reinforced bone cements: in comparison with the pristine G, the compression and bending strength of silanised G increased by 12% and by 13.7% respectively and the fracture toughness by 28%. These results provide very useful information on the relevance that the characteristics of the superficial oxidation of graphene have on the effectiveness of the silanisation process, besides an interesting functionalisation procedure for advanced dispersion and reinforcement of G-PMMA bone cements.

SILICA GRAFTED WITH EPOXIDIZED LIQUID POLYBUTADIENES: EVIDENCE FOR THE MECHANISM OF REINFORCEMENT

ABSTRACT Precipitated silica with backbone epoxidized liquid polybutadiene grafted onto its surface has recently been presented as a new reinforcement material that requires significantly less energy to disperse in comparison wtih the traditional in situ silanization process. This potentially provides better traction and hard-handling performance in car tire treads, without greatly increasing rolling resistance. The purpose of this study was to seek evidence proving the previously proposed reinforcement mechanism, through solid-state 1H low-field nuclear magnetic resonance and equilibrium swelling experiments. The evidence points to an increase in the amount of epoxidized chain segments chemically bonded to the silica surface and to an increase in coating-matrix entanglements with increases in the degree of epoxidation and cure of the coated silica. Such evidence is consistent with the hypothesis of increasing the number of entanglements and/or their progressive loss of mobility with an increase in the degree of epoxidation and decrease in temperature, which is in close agreement with the proposed mechanism.

Surface modification of alumina monolithic columns with 3-aminopropyltetraethoxysilane (APTES) for protein attachment

In the present work, a simpler and expedited functionalization method was used envisaging the preparation of functionalized alumina monoliths for effective purification of immunoglobulins. A single stage sol-gel synthesis method was used for the silanization of alumina monoliths with (3-Aminopropyl)triethoxysilane (APTES) in an aqueous environment. The nature of the attachment of APTES to the alumina and its distribution through the monolithic column was evaluated through FTIR-ATR, SEM-EDS and XPS measurements. Monolith silanization process was optimized by adjusting the reaction conditions in terms of catalyst used (acid or base), temperature and using a factorial design approach to elicit the interdependent influence of humidity, number of APTES coating layers and precursor concentration on the silanization of alumina. The reaction was found to be optimum at basic pH and a temperature of 80 °C. Etching-free functionalized monoliths with highest amine density of 166 µmol/g of the column were obtained using a single coating with a 2 M APTES solution, at 100% humidity. The binding capacity of the functionalized alumina monolith was determined using BSA and Protein A and then with the immunoglobulin G (IgG) aiming to infer about the suitability of the functionalized alumina monolith for purification of immunoglobulins. Adsorption-elution experiments showed that the functionalized alumina monoliths allowed the attachment of 0.78 mg IgG per mg of bound Protein A and the recovery of 89% of the captured IgG.