Macroporous Network Research Articles

Characterising and linking X-ray CT derived macroporosity parameters to infiltration in soils with contrasting structures

Soils deliver the regulating ecosystem services of water infiltration and distribution, which can be controlled by macropores. Parameterizing macropore hydraulic properties is challenging due to the lack of direct measurement methods. With tension-disc infiltrometry hydraulic properties near saturation can be measured. Differentiating between hydrologically active and non-active pores, at a given water potential, indirectly assesses macropore continuity. Water flow through macropores is controlled by macropore size distribution, tortuosity, and connectivity, which can be directly derived by X-ray computed tomography (CT). Our objective was to parameterize macropore hydraulic properties based on the imaged macropore network of three horizons of an Andosol and a Gleysol. Hydraulic conductivity Kunsat was derived from infiltration measurements. Soil cores from the infiltration areas were scanned with X-ray CT. Kunsat was significantly higher in the Andosol than in the Gleysol at all water potentials, and decreased significantly with depth in both soils. The in situ measurements guided the definition of new macroporosity parameters from the X-ray CT reconstructions. For the Andosol, Kunsat was best predicted using the imaged-limited macroporosity. A low total macroporosity, coupled with a high macropore density, indicated the abundance of smaller macropores, leading to homogeneous matrix flux. Imaged macropores were not well connected. In contrast, the Gleysol had a bi-modal macropore system with few very large, but well-connected macropores. Kunsat was best predicted using the imaged macroporosity consisting only of macropores with diameters between 0.75 and 3mm. Our research demonstrates that linking traditional soil physical measurements with soil-visualization techniques has a huge potential to improve parameterizing macropore hydraulic properties. The relevance of the relationships found in this study for larger scales and other soil types still needs to be tested, for example by a multi-scale investigation including a much wider range of different soils.

All-Solid-State Sodium-Selective Electrode with a Solid Contact of Chitosan/Prussian Blue Nanocomposite.

Conventional ion-selective electrodes with a liquid junction have the disadvantage of potential drift. All-solid-state ion-selective electrodes with solid contact in between the metal electrode and the ion-selective membrane offer high capacitance or conductance to enhance potential stability. Solution-casted chitosan/Prussian blue nanocomposite (ChPBN) was employed as the solid contact layer for an all-solid-state sodium ion-selective electrode in a potentiometric sodium ion sensor. Morphological and chemical analyses confirmed that the ChPBN is a macroporous network of chitosan that contains abundant Prussian blue nanoparticles. Situated between a screen-printed carbon electrode and a sodium-ionophore-filled polyvinylchloride ion-selective membrane, the ChPBN layer exhibited high redox capacitance and fast charge transfer capability, which significantly enhanced the performance of the sodium ion-selective electrode. A good Nernstian response with a slope of 52.4 mV/decade in the linear range from 10−4–1 M of NaCl was observed. The stability of the electrical potential of the new solid contact was tested by chronopotentiometry, and the capacitance of the electrode was 154 ± 4 µF. The response stability in terms of potential drift was excellent (1.3 µV/h) for 20 h of continuous measurement. The ChPBN proved to be an efficient solid contact to enhance the potential stability of the all-solid-state ion-selective electrode.

Porous glass-ceramic orbital implants: A feasibility study

Surgical removal of a diseased ocular globe is followed by the placement of a permanent orbital implant in the patient’s anophthalmic cavity to provide adequate support to surrounding tissues. We fabricated foam-like CaSiO3-containing glass-ceramics that exhibited favorable micro-architectural characteristics for use as orbital implant materials, i.e. a network of open and large macropores (∼250 µm) that could potentially allow ingrowth of fibrovascular tissue. The implants had an excellent chemical stability in contact with simulated body fluids (no mass losses were registered after soaking for 1 month in vitro) and high mechanical strength (∼20 MPa under compression) to permit safe manipulation during surgery. Therefore, this new glass-ceramic porous material is a promising, potentially less expensive alternative to existing polymeric or ceramic bioinert orbital implants.

Setting Directions: Anisotropy in Hierarchically Organized Porous Silica.

Structural hierarchy, porosity, and isotropy/anisotropy are highly relevant factors for mechanical properties and thereby the functionality of porous materials. However, even though anisotropic and hierarchically organized, porous materials are well known in nature, such as bone or wood, producing the synthetic counterparts in the laboratory is difficult. We report for the first time a straightforward combination of sol–gel processing and shear-induced alignment to create hierarchical silica monoliths exhibiting anisotropy on the levels of both, meso- and macropores. The resulting material consists of an anisotropic macroporous network of struts comprising 2D hexagonally organized cylindrical mesopores. While the anisotropy of the mesopores is an inherent feature of the pores formed by liquid crystal templating, the anisotropy of the macropores is induced by shearing of the network. Scanning electron microscopy and small-angle X-ray scattering show that the majority of network forming struts is oriented towards the shearing direction; a quantitative analysis of scattering data confirms that roughly 40% of the strut volume exhibits a preferred orientation. The anisotropy of the material’s macroporosity is also reflected in its mechanical properties; i.e., the Young’s modulus differs by nearly a factor of 2 between the directions of shear application and perpendicular to it. Unexpectedly, the adsorption-induced strain of the material exhibits little to no anisotropy.

Nanostructured Three-Dimensional (3D) Assembly of 2D MoS2 and Graphene Directly Build From Acidic Graphite Oxide.

A 3D highly interconnected macroporous network of reduced GO having finely dispersed few-layered 2D MoS2 nanosheets was constructed through direct use of acidic graphite oxide (GO) for the first time. This facile and technologically scalable process can afford efficient hydrodesulfurization electrocatalysts as potential anode materials at lower cost, and can circumvent the poor thermal stability and recyclability of the material. The strategy provided here can be the basis to design and develop practical processes to address the ultimate goal of large-scale manufacturing of hybrids composed of 2D materials for various energy and catalysis applications.

The Comparison Of Different Activation Techniques To Prepare Activated Carbon Materials From Waste Cotton Fabric

Abstract In this paper, we investigate on the preparation of waste cotton fabric-based activated carbons by different methods. Two different kinds of carbon materials are prepared from waste cotton fabric, the structure and properties were characterized using instrumental analyses such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). It is revealed that the products prepared using one-step process are composed of macroporous carbon network , which looks like sponge-type morphology, and exhibit the high values of qiodine (1,198 mg/g) and qmb (235.6 ml/g), showing their potential usage as adsorbent.

Spatial Distribution of Organic Matter Compounds at Intact Macropore Surfaces Predicted by DRIFT Spectroscopy

Core Ideas Clay coatings in Bt horizons are enriched in heterocyclic organic matter compounds. The enrichment results from preferential transport in the soil macropore network. These compounds probably originate from long‐term humification and biomass combustion. Py‐FIMS and DRIFT spectroscopy approach enables millimeter‐scale spatial characterization. The illuvial Bt horizon of Luvisols is characterized by coatings of clay and organic matter (OM) at the surfaces of cracks and biopore walls. The occurrence and distribution of OM compounds such as heterocyclic N compounds (NCOMP) and benzonitrile and naphthalene (BN+NA) in macropore coatings could have important effects on preferential transport processes in structured soil. The objective of this study was to estimate the millimeter‐scale distribution of NCOMP and BN+NA at intact surfaces of coated and uncoated cracks, pinholes, and burrow walls. The proportions of NCOMP and BN+NA in OM were determined by pyrolysis–field ionization mass spectrometry (Py‐FIMS) from disturbed material that was manually separated from the intact sample surfaces. Fourier‐transform infrared spectroscopy in diffuse reflectance mode (DRIFT) and partial least squares regression (PLSR) between DRIFT signals and Py‐FIMS data were used to generate millimeter‐scale maps of predicted NCOMP and BN+NA proportions at intact macropore surfaces. The NCOMP and BN+NA proportions were linearly related to C=O and C=C groups from OM and to O–H groups from clay minerals in DRIFT spectra. The millimeter‐scale distribution of NCOMP and BN+NA at intact macropore surfaces could be predicted in terms of relative differences among the macropore types. Increased NCOMP and BN+NA proportions corresponded to the spatial distribution of crack coatings and pinholes. The relative enrichment suggested that pyrogenic OM has been preferentially transported in cracks rather than in biopores and that it was stabilized by clay minerals and prevented from decomposition. The results indicated that preferential transport affects OM turnover processes in the subsoil.

Macroporous carrier-free Sr-Ti catalyst for NOx storage and reduction

A novel concept is presented, consisting of a macroporous carrier-free catalyst. As a proof of concept, a novel Cu-containing Sr-Ti NSR catalyst with a macroporous network has been synthesized, and its maximum NOx storage capacity (1500μmolNOx/gcatalyst) significantly surpasses that of conventional Pt/Ba/Al2O3 formulations (∼600–800μmolNOx/gcatalyst). This high NOx storage capacity is achieved because the active phases (mainly SrCO3 and Cu-containing Sr-Ti perovskites, as deduced by XRD) are not diluted in an inert carrier, and this can be done because the macroporous structure obtained using a polymethylmethacrylate colloidal crystal template allows the access of gases to the particles bulk. In situ DRIFTS experiments showed that NOx were chemisorbed on the novel Cu-containing Sr-Ti macroporous catalyst as a mixture of nitrite and nitro species, and this suggests that several NOx chemisorption pathways are simultaneously taking place probably involving chemisorption of both NO and NO2. Additionally, this novel catalyst is totally selective towards N2 formation as NOx reduction product, without traces of N2O nor NH3. CO2 and H2O compete with NOx for being chemisorbed on the catalyst, and this hinders the utilization of this catalyst in real diesel exhausts. However, we believe that this new concept of macroporous carrier-free catalyst could be extended to other heterogeneous catalyzed reactions or materials to avoid the diluting effect of the catalyst support.

Unidirectional freezing as a tool for tailoring air permeability in macroporous poly(ethylene glycol)-based cross-linked networks

Unidirectional freezing followed by photopolymerization at subzero temperatures was used to obtain highly air-permeable monoliths with ordered porous structures. Scaffolds were obtained from aqueous solutions of a poly(ethylene glycol)dimethacrylate (PEGDMA) oligomer, a photosensitizer and a reducing agent. Solutions were vertically frozen in liquid nitrogen at a controlled rate to induce the oriented growth of ice crystals and then cryo-photopolymerized under blue-light irradiation. Ice crystals were finally removed under vacuum producing macroporous hydrophilic networks with aligned pores. Porosities ranged between 80 and 95%, depending on the initial concentration of PEGDMA. The influence of processing variables on the final properties of the materials was addressed, concerning particularly the effect of porosity and freezing directionality on air permeability. Compared to porous PEGDMA-based monoliths with non-aligned macropores, gas permeability was two to three times higher for oriented scaffolds at the same porosity level, a fact explained by the easier transport of gas molecules through the aligned structures. However, the role of pore orientation on gas permeability was shown to be less marked as porosity increased. The results demonstrate that the use of unidirectional freezing strongly increases the permeability of monolithic samples up to values usually required, for instance, in tissue engineering applications (higher than 2D). These findings provide new perspectives on pore design principles toward future scaffolding of polymeric cross-linked matrices.

Retention of 226Ra by barite: The role of internal porosity

The role of internal macropores and nano-scale pores for the uptake of 226Ra into barite was studied via scanning and transmission electron microscopy as well as focused ion beam methods. A temporal evolution of the internal microstructure and the Ra distribution was observed on samples taken from long-term Ra uptake experiments. The results of this study clearly show a significant impact of the presence of Ra leading to a complete reconstruction of the internal barite microstructure, whereas the microstructure of Ra-free reference samples remained unchanged. The initial internal barite microstructure contains a connected network of macropores and a layered structure of nano-scale pores which, in the presence of Ra, coalesced in favor of larger pores during the experiment. A clear relationship between the Ra uptake and the internal porosity was observed by high-resolution STEM-EDX mappings. Starting from strongly enhanced Ra concentrations in the solid in the vicinity of the pores, Ra is temporarily inhomogeneously distributed within the barite particles. At later stages of the long-term experiment the Ra distribution becomes homogenous while nano-scale and macro-scale pores disappear. In conclusion, the uptake of Ra into barite takes place by a special case of dissolution/reprecipitation from the inside of the particle to the outside.

Subsurface flow and large-scale lateral saturated soil hydraulic conductivity in a Mediterranean hillslope with contrasting land uses

Abstract The lateral saturated hydraulic conductivity, Ks,l , is the soil property that mostly governs subsurface flow in hillslopes. Determinations of Ks,l at the hillslope scale are expected to yield valuable information for interpreting and modeling hydrological processes since soil heterogeneities are functionally averaged in this case. However, these data are rare since the experiments are quite difficult and costly. In this investigation, that was carried out in Sardinia (Italy), large-scale determinations of Ks,l were done in two adjacent hillslopes covered by a Mediterranean maquis and grass, respectively, with the following objectives: i) to evaluate the effect of land use change on Ks,l , and ii) to compare estimates of Ks,l obtained under natural and artificial rainfall conditions. Higher Ks,l values were obtained under the maquis than in the grassed soil since the soil macropore network was better connected in the maquis soil. The lateral conductivity increased sharply close to the soil surface. The sharp increase of Ks,l started at a larger depth for the maquis soil than the grassed one. The Ks,l values estimated during artificial rainfall experiments agreed with those obtained during the natural rainfall periods. For the grassed site, it was possible to detect a stabilization of Ks,l in the upper soil layer, suggesting that flow transport capacity of the soil pore system did not increase indefinitely. This study highlighted the importance of the experimental determination of Ks,l at the hillslope scale for subsurface modeling, and also as a benchmark for developing appropriate sampling methodologies based on near-point estimation of Ks,l .

Template-free fabrication of hierarchically meso/macroporous architecture of layered double hydroxide by dry gel conversion method

A new type of hierarchically porous architecture of Mg2+, Al3+-containing layered double hydroxide, with well defined mesoporous/macroporous structure, has been fabricated by dry gel conversion method without the need of a surfactant and organic solvent. Predefined amorphous aluminum hydroxide gel and anhydrous magnesium sulfate were used as Al and Mg precursor material, respectively, and aqueous ammonia as precipitating agent. The resulting self-sustaining hierarchical layered double hydroxide material exhibits a bi-modal porous structure having a macroporous network with macropore sizes of 100–200 nm and a well defined mesoporous structure of pore size around 3.9 nm in the macroporous framework. Layered double hydroxide crystallites are aligned with a multilayer manner to form the architecture structure. The formation process of layered double hydroxide architecture, such as the evolution of phase composition, pore structure, and particle morphology with reaction time was further verified and the formation mechanism is postulated.

Additive Manufacturing of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(ε-caprolactone) Blend Scaffolds for Tissue Engineering.

Additive manufacturing of scaffolds made of a polyhydroxyalkanoate blended with another biocompatible polymer represents a cost-effective strategy for combining the advantages of the two blend components in order to develop tailored tissue engineering approaches. The aim of this study was the development of novel poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/ poly(ε-caprolactone) (PHBHHx/PCL) blend scaffolds for tissue engineering by means of computer-aided wet-spinning, a hybrid additive manufacturing technique suitable for processing polyhydroxyalkanoates dissolved in organic solvents. The experimental conditions for processing tetrahydrofuran solutions containing the two polymers at different concentrations (PHBHHx/PCL weight ratio of 3:1, 2:1 or 1:1) were optimized in order to manufacture scaffolds with predefined geometry and internal porous architecture. PHBHHx/PCL scaffolds with a 3D interconnected network of macropores and a local microporosity of the polymeric matrix, as a consequence of the phase inversion process governing material solidification, were successfully fabricated. As shown by scanning electron microscopy, thermogravimetric, differential scanning calorimetric and uniaxial compressive analyses, blend composition significantly influenced the scaffold morphological, thermal and mechanical properties. In vitro biological characterization showed that the developed scaffolds were able to sustain the adhesion and proliferation of MC3T3-E1 murine preosteoblast cells. The additive manufacturing approach developed in this study, based on a polymeric solution processing method avoiding possible material degradation related to thermal treatments, could represent a powerful tool for the development of customized PHBHHx-based blend scaffolds for tissue engineering.

Quantifying the impact of a succession of freezing-thawing cycles on the pore network of a silty clay loam and a loamy sand topsoil using X-ray tomography

In the Nordic countries, changes in pore structure during winter can affect e.g. water transport capacity in soils after winter. A reduction in pore space can cause an increase in runoff volume due to snowmelt and rain, resulting in flooding and soil erosion. This study quantified the effect of freezing-thawing cycles (FTCs) on the macropore structure of a silt and a sandy soil. Six consecutive FTCs were applied to intact soil samples, which were scanned after 0, 1, 2, 4 and 6 FTCs with an industrial X-ray scanner. Using state-of-the-art image processing and analysis techniques, changes in soil macropore network characteristics were quantified. The results showed that freezing-thawing affected the looser sandy soil more than the silt with its more cohesive structure. However, in both soils freezing-thawing had a negative effect on properties of macropore networks (e.g. reduction in macroporosity, thickness and specific surface area of macropores). These findings can help improve understanding of how undisturbed soils react to different winter conditions, which can be beneficial in the development of models for predicting flooding and soil erosion.

The Response and Limits of Fast Discharge and Charge Rates of Electrodeposited V2O5 Inverse Opal Networks in Lithium Batteries

Structurally stable electrodeposited vanadium pentoxide inverse opal networks on FTO-coated glass are electrochemically tested as a function of C-Rate (discharging and charging) in this study. Recent applications of IOs in electrochemical energy storage have proven that their open-worked structure promotes more stable Li-ion intercalation during cycling(1-3), exhibit improved rate capability due to increased surface area and decreased path lengths for Li+ insertion,(4-7). Rate limitations associated with standard Li-ion batteries can be improved in principle due to shorter diffusion lengths in the 3D architecture(8, 9), particularly important for charging in full cells. V2O5 has been widely investigated(10) as a cathode material for Li-ion batteries due to its high theoretical specific capacity and is useful for reversible Li-ion insertion and removal due to its mixed valance and layered structure.(11) The difference in open-topped versus overfilled (closed top) 3D inverse opal macroporous V2O5 networks, due to electrodeposition growth time, is examined by galvanostatic cycling, and both 3D structure are examined at C-rates in the range 0.5 – 30 C. Electrochemical analysis demonstrates how lithium phase changes increasing C-rate in both open and overfilled network cases, with capacity values investigated after 25 charge/discharge cycles. Raman scattering and X-ray diffraction is used to investigate the change in structure and phase in each case at each C-rate, along with SEM images to visual investigate the effect of C-rate on the V2O5 inverse opal networks.

Three-dimensionally assembled Graphene/α-MnO2 nanowire hybrid hydrogels for high performance supercapacitors

We present a facile hydrothermal method to produce graphene-metal oxide composite that offer synergistic effect of three-dimensional (3D) graphene and electroactive α-MnO2 nanowires to improve high energy storage capability in supercapacitors. The graphene/α-MnO2 nanowire hydrogel is prepared via a simple hydrothermal route, in which graphene and α-MnO2 nanowires are self-assembled into 3D macroporous network structures. An asymmetric supercapacitor device is fabricated by using graphene/α-MnO2 nanowire hydrogel as positive electrode and 3D graphene hydrogel as negative electrode in an aqueous Na2SO4 electrolyte. The asymmetric cell can be cycled in the wide voltage range of 0–2V and exhibit a gravimetric energy density of 38Whkg−1 with a maximum power density of 258kWkg−1. In addition, it shows a good cycle stability with ∼94% capacitance retention after 1000 cycles. The graphene/α-MnO2 nanowires hybrid hydrogels may have great potential in developing energy storage devices with high energy and power densities.

The Manifold Varieties of Poly(2‐Hydroxyethyl Methacrylate) Hydrogels−IPNs

SummaryThe interpenetrating network structure was used to control mechanical properties of hydrogels based on poly(2‐hydroxyethyl methacrylate) (PHEMA) (first network (A) or second network (B)) and poly(glycerol methacrylate) (PGMA) (network B). In order to understand the structure, mechanical and swelling properties of sequentially made IPN hydrogels, the swollen PHEMA network microstructure and its formation was investigated by means of swelling and SWAXS experiments. Visually clear and microscopically homogenous hydrogel networks based on poly(2‐hydroxyethyl methacrylate) revealed presence of domains of size 1–10 nm formed during polymerization in the presence of water. The study was carried out to understand conditions under which the hydrophobic interactions are operative and their effect on the microstructure as well as how they change when the double network structure is introduced. The morphologies of network A ranged from homogenous, non‐porous, and optically clear gels, to macroporous gels resulting from phase separation and offering fused‐sphere morphology. A cryogel characterized by large elongated and partially interconnected pores of tens to hundreds micrometers were another object for comparison. In most cases, an increase of tensile moduli and improvement of ultimate tensile properties was achieved. A surprisingly high increase in true strength (by a factor of 10 – 30) was achieved when the macroporous PHEMA network A was reinforced by weak PHEMA or PGMA networks B. All these weakly crosslinked IPN gels were optically clear.

Efficient Removal of Cationic and Anionic Dyes from Aqueous Solution Using Cellulose-g-p(AA-co-AM) Bio-Adsorbent

The removal of cationic methylene blue (MB) and anionic acid red 1 (AR1) dyes from aqueous solution was studied using cellulose-g-p(AA-co-AM) bio-adsorbent (CP bio-adsorbent). The CP bio-adsorbent with surface multiple functional groups and macroporous network structure was synthesized via grafting the acrylic acid (AA) and acrylamide (AM) onto cellulose molecules. The adsorption behavior of the bio-adsorbent to dyes in the aqueous solution was studied. The effects of solution pH, temperature, initial dye concentration, and contact time on the adsorption capacity of the bio-adsorbent were investigated. Due to the abundant functional groups and macroporous network structure, the CP bio-adsorbent exhibited remarkable adsorption performance for the removal of type dyes with an equilibrium adsorption capacity of 998 mg·g-1 for MB and 523 mg·g-1 for AR1. The kinetic studies revealed that the adsorption of dyes was exactly described by a pseudo-second-order kinetic model. Comparison with other bio-adsorbents confirmed that the eco-friendly CP bio-adsorbent possessed excellent potential for water purification.

Novel calcified gum Arabic porous nano-composite scaffold for bone tissue regeneration

The aim of this study was to investigate the biomechanical and biological properties of a nanocomposite scaffold containing both mineral and polysaccharide constituents. Hydroxyapatite nanoparticles (n-HA) was synthesized from dead abra ovata shells using wet chemical methods and was used in different ratios in concert with gum Arabic, a branched plant polysaccharide. N-HA/gum nanocomposite was fabricated with freeze-drying process and characterized by FTIR and SEM for chemical structure and morphology. Porosity was estimated using liquid substitution method. The scaffold mechanical properties were evaluated by compressive test measurement. Osteogenic differentiation was assessed using alkaline phosphatase production and biomineralization was evaluated using Alizarin red assay. Results demonstrated that the hydroxyapatite/gum Arabic nanocomposite had favorable biocompatibility and a similar structure to natural bone matrix. Porous nanocomposite possessed macropore networks with a porosity 87–93% and mean pore size ranging between 164 and 230 μm. The gum/HA with a ratio of 50% w/w HA had the highest compressive modulus of ∼75.3 MPa Pa (MPa) and the ultimate compressive stress of ∼16.6 MPa. C2C12 cells cultured on a scaffold with higher percentage (40 and 50 w/w) of HA demonstrated increased ALP levels and calcium deposition. The data from the present study demonstrated significant changes to the biomechanical properties and osteoconductivity of the nanocomposite scaffold by modulating its mineral content. Nanocomposite scaffolds containing gum and n-HA of 40–50% exhibited highest mechanical properties, as well as supported increased biomineralization.

Chitosan–graphene oxide films and CO2-dried porous aerogel microspheres: Interfacial interplay and stability

The intimate interplay of chitosan (CS) and graphene oxide (GO) in aqueous acidic solution has been explored to design upon casting, nanostructured “brick-and-mortar” films (CS-GO-f) and by acidic-to-basic pH inversion, porous CO2-dried aerogel microspheres (CS-GO-m). Owing to the presence of oxygenated functional groups in GO, good-quality crack-free hybrid films were obtained. Mechanical properties were improved independently of the GO content and it was found that a 20wt% loading affords hybrid film characterized with a Young modulus three times superior to that reached with the same loading of layered clay. The presence of graphene oxide was found to be detrimental for the thermal stability of the polysaccharide at T <350°C, a fact attributed to the well-established decomposition of the oxygenated functional groups of the graphene sheets. Irrespective to the graphene oxide loading, chitosan-graphene oxide mixture preserves the gelation memory of the polysaccharide. Supercritical drying of the resulting soft hydrogels provides macroporous network with surface areas ranging from 226m2g−1 to 554m2g−1. XPS and RAMAN analyses evidenced the selective reduction of GO sheets inside of these microspheres, affording the hitherto unknown macroporous chitosan-entangled-reduced graphene oxide (CS-rGO-m) aerogels. Improvement in both hydrothermal stability (under water reflux) and chemical stability (under acidic conditions) have been noticed for chitosan-graphene oxide microspheres with respect to non-modified chitosan and chitosan-clay bio-hybrids, a result rooted in the substantial hydrophobic character imparted by the addition of graphenic material to the polysaccharide skeleton. In essence, this contribution demonstrates that graphene oxide loading do not disturb neither the filmogenicity of chitosan nor its gelation ability and constitutes a promising route for novel chitosan-based functional hybrid materials.