Use Of Cork Research Articles

Cork Façades as an Innovative and Sustainable Approach in Architecture: A Review of Cork Materials, Properties and Case Studies.

Façades give the first impression of a structure, reflecting the overall aesthetic appeal, architectural styles, cultural influences, and technological advancements. Emphasis on sustainability is increasing, with a shift towards eco-friendly and energy-saving materials, triggered by decreasing the environmental impact of construction. Cork is a green competitive material for various engineering and design applications due to its biological formation, sustainable production and a portfolio of properties including low density, impermeability, viscoelastic behaviour and high thermal insulation that derive from its cellular and chemical features. This work presents cork materials used in building façades and their properties, also giving information on cork production and processing into cork-based products as a review of the existing published research, while also identifying knowledge gaps and further research needed. Historical examples of cladding of constructions with raw cork are given, while the contemporary innovative use of cork façades was triggered by some designs of well-known architects with outdoor application of expanded cork agglomerates. Examples of different historical and contemporary constructions were assembled and critically assessed by the authors. The aim is to give integrated information of cork as a natural, renewable and sustainable material to raise the interest of designers, architects and engineers to explore cork, blending aesthetics with environmental responsibility, targeting a more sustainable and resilient built environment.

A comparison between the use of cork and synthetic aggregates in the production of geopolymer composites

Innovative and multifunctional building materials with low embodied energy and reduced CO2 emissions have attracted considerable attention. Herein, a comprehensive comparison between the use of cork and commercial synthetic aggregates (expanded vermiculite, expanded polystyrene (EPS), and lightweight expanded clay (Leca®)) in the production of geopolymer composites was performed. Additionally, composites containing rubber coming from the recycling of end-of-life tires were also studied. The impact of the aggregate nature and amount on the geometric density, compressive strength, thermal conductivity, sound absorption coefficient, and thermal stability of the composites was evaluated. This investigation demonstrates the feasibility of tuning the geopolymer composites properties according to the envisioned application, cork-composites being the most suitable approach for sound absorbing panels (α = 0.8, 20003150 Hz), while Leca® and expanded vermiculite containing composites are the best option when considering fire resistant applications.

3D printing lightweight mortars with cork to improve thermal efficiency in buildings

3D printing lightweight aggregate concrete potentially allows building components with reduced thickness and lighter structures. However, the effect of lightweight additives in 3D printing compositions, particularly the use of cork, in the fresh and hardened properties of 3DP is still unknown. This study demonstrates that adding increasing amounts of cork (0%, 25%, 50%, 75%, and 100%) in place of fine sand enhances the insulation of printable mortars. Cork mortars positively reduced the required yield stress at the bottom layer in the fresh state due to lighter bulk densities. Attaining lower hardened densities (1363.0–1791.5 Kg/m3), printed mortars with high amounts of cork (50, 67, and 100%) showed fair values of thermal conductivity ranging between 0.40 and 0.96 W/mk, for a value of 1.42 W/mk of the reference. Cork composites presented sufficient mechanical strength, with a compressive strength between 21.1 MPa at 100% cork and 51.1 MPa at 17% cork compared to 58.3 MPa of reference mortar. Printing did not considerably affect strength development or thermal conductivity in printed mortars. The latest showed isotropic behavior in all test directions, while mild anisotropy was found for compressive and tensile strength. Micro and macrostructure analysis revealed that printing reduces macropores in the sample's core relative to the compaction of lightweight aggregate mortars. When applied on a large scale, these composites can bring printed constructions closer to meeting thermal comfort standards with reduced self-weight.

The Use of Cork and Silicone Rubber with Embedded Sensors in Sports' Smart Protections: Studies on the Impact Absorption Performance

In several sports, such as martial arts, point scoring depends on applied impact. Embedded sensors in wearable protection devices help to quantify the impact intensity. In parallel, there is a growing interest in developing products with a reduced ecological footprint, using natural materials such as cork. Considered a light, resilient, flexible, and hypo-allergenic material, cork has been proving to be a material with interesting impact absorption properties to be integrated into personal protection, as is the case with helmets and vests. Silicon rubber has also been proposed as an alternative elastomer material with adequate sealing and electrical isolation properties, while resistant to ageing and impact. Since injuries occur more frequently in lower extremities, presented work is part of a project that aims to explore the interest of replacing foams and synthetic leathers usually applied in foot protections with smaller CO2 footprint materials while increasing their impact absorption properties. At this stage, a part of a protection prototype consisting of a plate made from natural cork, coated with silicone rubber protection containing embedded force sensors, was studied. The objective is to explore the potential of such materials to replace those conventionally applied in commercial foot protections. Firstly, the adhesion between imprinted silicon and cork was confirmed through peeling tests. Then, considering the opportunity of inserting sensors within the additive manufacturing of the parts, different silicone coating configurations and sensor placements were tested regarding their impact performance. Comparison between impact absorption performance was carried out using an impact test device, assessing sandwich composite performance and force sensing reading accuracy. Silicone printability during the robocasting extrusion technique demonstrated to facilitate the sensor placement without requiring deposition path modification. It showed to be an easy way to manipulate the sensor position within the composite layers and, by that, to modify its impact performance. This is an important contribution to the main goal of the undergoing project, which is to completely replace commercial materials with this new sandwich composite.

Application of Disposable Pipette Extraction for Determination of Yb by High‑Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry Using Lanthanum as a Chemical Modifier

The use of extraction technique with disposable tips (DPX) was applied for the first time for the extraction and preconcentration of Yb in samples of liquid waste from the petrochemical industry and environmental water using bioabsorbent cork. The use of cork as an extracting phase in the determination of Yb by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) was evaluated. The pyrolysis and atomization temperatures were optimized at 1400 and 2400 ºC, respectively. H2SO4, HNO3 and HCl acids were compared in the steps of cleaning the extraction phase and desorption of the analyte by DPX. The best extraction in the selected conditions was obtained with pH 8.0 and 5% v/v HCl. The recoveries were close to 100% for residual water and drinking water, 33 to 77% for produced water and 64 to 93% for river water. Tests with interfering ions in different concentrations were performed. The relative limit of quantification (LOQ) and limit of detection (LOD) were estimated at 0.03 and 0.01 µg L-1, respectively. The total time for the preparation of the samples by DPX was close to 1 min per sample. Extraction and pre-concentration were observed using DPX with a preenrichment factor of approximately 4 times.

Expanding the use of cork as biosorbent through the determination of new psychoactive substances in postmortem blood samples

This study aimed to investigate the applicability of cork in a solid phase-based extraction method coupled to a 96-deepwell plate for LC-MS/MS determination of new psychoactive substances and other drugs of abuse in blood. Nowadays, there is a concern in developing new analytical methods that follows the principles of “green analytical chemistry”. These include the miniaturization of methods, utilization of minimal sample and solvent volumes, development of greener solvents and sorbents, among others. Regarding sorbents, natural compounds such as cork can be a great choice to be employed as extraction phase due to its large availability and low cost. Nevertheless, these new materials can help overcome analytical challenges related to postmortem analysis. Regarding sample preparation, blood samples were primarily submitted to protein precipitation by mixing 200 μL of blood, 250 μL of water, 250 μL of zinc sulfate and 50 μL of NaOH, followed by agitation and centrifugation. An aliquot of 500 μL of the supernatant was added to a 96-deepwell plate containing 30 mg of cork powder with particle size ≤ 250 μm. Extraction was performed by agitation for 15 minutes in an orbital shaker at 300 rpm, with consecutive removal of the aqueous phase. Desorption was performed by the addition of 1150 μL of acetonitrile with further agitation at 300 rpm for 2 minutes. The organic layers were recovered and dried under nitrogen stream, reconstituted in 30 μL of methanol and 2 μL was injected in the analytical system. Sample preparation parameters were optimized through univariate and multivariate strategies with the software Statistica 8.0 (Statsoft, Tulsa, USA). A Nexera UFLC system coupled to a LCMS-8045 triple quadrupole mass spectrometer (Shimadzu, Japan) was used for the analysis. Separation was performed on an Acquity UPLC® BEH C18 (1.7 μm, 2.1 × 50 mm) column (Waters, USA) using water (A) and acetonitrile (B) both containing 0.1% formic acid as mobile phases. Total run time was 7.5 minutes. The method was validated according to ANSI/ASB Standard 036 for the following parameters: lower limit of quantification (LLOQ), linearity, carryover, selectivity, precision, bias and dilution integrity. To verify the applicability of the method, three real postmortem blood samples were analyzed. The optimization of extraction parameters was carried out for the following items: choice of cork conformation (powder or sheet), cork particle size, cork mass, extraction time, desorption time, solvent type and solvent volume. The best parameters values are described in “Methods” session. LLOQs ranged between 0.5 and 5 ng/mL. Calibration curves were linear through the ranges of 0.5–85 ng/mL for ethylone, MDA, MDMA, N-ethylpentylone, 25B-NBOMe, 25C-NBOMe, 25I-NBOMe, fentanyl, pentylone and LSD; 1–85 ng/mL for cathinone, mephedrone and PCP; and 5–100 ng/mL for 25-NBOH, with determination coefficient (r2) > 0.99 and absence of carryover effects. Bias, within-run and between-run precision and dilution integrity results were within the acceptable values. The three samples were positive for the presence of MDA and MDMA with concentrations ranging between 23.11–26.59 ng/mL and 79.21–198.13 ng/mL, respectively. Sample preparation optimization was found to be relevant for the achievement of better analytical responses. Additionally, the use of the 96-deepwell plate allows simultaneous processing of multiple samples, with further possibility of automation. This study demonstrate that cork can be employed as a biosorbent for the determination of NPS and other drugs of abuse in postmortem blood through proper optimization, validation and application of the methodology. Therefore, it can be an alternative extraction phase to be considered in method development for toxicological purposes.

인테리어 소재활용을 위한 코르크의 전자현미경 연구

The scope of interior design today covers almost all buildings, including houses, offices, shops, hospitals, hotels, restaurants, cafes, department stores, beauty salons, clothing stores, factories, schools, etc. All buildings inhabited by humans. The materials most used as interior materials for interior construction are wood, stone, tiles, bricks, blocks, cement and concrete, metal materials, glass, painting materials, secret materials, waterproofing materials, plastic materials, wallpaper, carpets, curtains. and blinds and window materials. Although the durability aspect is considered a lot, and the lifespan issue is being paid a lot of attention, it is the design that cannot be discarded nonetheless. Since interest in interiors is increasing these days, the appearance and materials of buildings are also very important. Cork is starting to get a lot of attention as an interior material. Currently, the most widely used use of cork is a wine stopper. This is because it has the unique elasticity and waterproofness of cork. Cork is a material often used for interior accessories. Cork, with its unique texture, is attractive enough on its own, but can be used for insulation or room use. As a result of scanning microscopic analysis of wine cork and commercial cork, the difference in microstructure was not significant.

Phenolic Compounds in Cork-Closed Bottle-Fermented Sparkling Wines

Bottle fermented sparkling wine in South Africa is known as Methode Cap Classique which is based on the method used in France for Champagne. The use of cork, instead of a crown cap during the second fermentation in sparkling wine was investigated for its effect on the phenolic profile of wines. Phenolic acids susceptible to migration from cork into wine were studied in two-disc corks from three different commercial suppliers, coded as Cork A, Cork R and Cork C and a crown cap closure. Gallic, caftaric, caffeic and p-coumaric acids were quantified in all samples using a liquid chromatographic technique. Physicochemical parameters were also measured in the wine using a spectrophotometric technique. Total acidity and pH were not significantly different among the wines. Cork R wines were however significantly different in alcohol. Residual sugar for all samples was below the limit of detection. Gallic acid was significantly highest in Cork A wines, which indicates the contribution of Cork A to the concentration of this compound in the wine. Different cork types are assumed to release different concentrations of phenolic compounds. This may be due to differences in surface roughness of cork that would increase the surface area in contact with the wine. Therefore, corks from different origins (suppliers) could be used to bring about subtle differences to the wine.

Innovative screen-printed electrodes on cork composite substrates applied to sulfadiazine electrochemical sensing

Abstract This work reports the first use of cork as substrate to produce 3-electrode electrochemical devices, which may be very important to conduct sustainable worldwide biochemical testing in point-of-care. It consists of laminated cork covered by a thin-film of an insulating resin and printed in a 3-electrode system format. Silver ink was used to print electrical tracks and the reference electrode, while carbon ink was used to print working and auxiliary electrodes. The analytical performance of the cork-based devices was and compared to other common supports, as PET and ceramics in the form of screen-printed electrodes (SPEs). The cork-based devices displayed higher current values and better reversibility features and were able to undergo stable modification with conductive nanomaterials. They were further applied to detect sulfadiazine (SDZ), an antibiotic of human use that is also an environmental contaminant, by modifying the working electrode with a molecularly imprinted polymer (MIP) layer obtained by electropolymerization of pyrrol. The results confirmed the ability of the MIP film to detect SDZ selectively and showed reproducible increasing current signals for increasing concentrations of SDZ, from 8.0 to 186.0 μM. Direct comparison with commercial carbon SPEs showed greater sensitivity for the cork-based SPEs, with 10× lower limits of detection. Overall, cork-based devices are a valuable alternative to currently available SPEs systems, considering environment and cost features and also the analytical gains of this approach. These are especially important in times where a global biochemical testing became necessary for improved public health management.

The use of cork in the thermoregulation of the hive: an innovation attempt to enhance non-wood products and beekeeping in Mediterranean forests

Hive thermoregulation is fundamental for the normal development of bee colonies and, consequently, hive productivity and honey bee health. External conditions mainly affect the walls of the hive. Therefore, hive construction materials and thermal conductivity features can influence its thermoregulation efficiency. The present trial made a comparison of experimental hives (modified Dadant-Blatt of 10 frames) made with cork as thermal insulator and conventional hives made entirely with firwood to evaluate their effects on thermoregulation of Apis mellifera ligustica colonies in Northwerstern Sardinia (Italy). The cork-modified beehives consisted of common conventional beehives modified by replacing the wooden walls with cork walls (pressed cork), whereas the control beehives (wooden hives) consisted of standard Dadant Blatt beehives entirely made of firwood. Environmental (especially nest internal temperature) parameters were assessed periodically. The daily temperature pattern of cork-modified beehives was more regular than that of control beehives. In addition, bees had a more efficient winter thermoregulation in cork-modified beehives compared with control hives.

La explotación corchera en el protectorado de España en Marruecos: del monopolio a INCOME a la fiebre del corcho (1944-1956)

Dado que en los últimos años se ha renovado el interés por los estudios sobre la presencia española en el Norte de Marruecos entre 1912 y 1956, este trabajo pretende explicar los pormenores de la política que la Administración del Protectorado desarrolló en cuanto a los aprovechamientos del corcho entre 1944 y 1956. Después de un minucioso estudio de la documentación existente, analizamos los acontecimientos que se sucedieron desde la concesión en régimen de monopolio a la empresa “Industrias Corcheras del Marruecos Español” de todos los aprovechamientos del corcho hasta la aparición de lo que en aquellos años se conoció como la fiebre del corcho, un proceso donde unieron sus caminos la conflictividad inherente que generaron los que buscaban exclusivamente el beneficio propio y la que se avivó en los últimos años de la presencia española al amparo de los vientos independentistas que asolaban el Protectorado. Todo ello sin olvidar, la cuota de responsabilidad tanto de la empresa como de la administración española que no supieron llevar a cabo las enormes expectativas que se habían generado.

Development and characterization of a new cork-based material

The use of cork in polymers is an effective approach to develop new sustainable materials, with the current challenges facing the world regarding on the environmental impact of synthetic polymers. Cork granules are delivered as waste by the industry preparing coating plate and cork ventures. These granules can be used in the preparation of composites, to the reason of their low density. This work presents the preparation of biocomposites resulting from the combination of the poly (ε-caprolactone) with cork (10–30 wt and maleic anhydride-grafted polyethylene (MAPE) as compatibiliezr agent. A twin-screw extruder and injection molding are used in order to obtain the tensile samples. The obtained composites were characterized for mechanical and thermal properties, morphology, and water absorption behavior. All composites demonstrated a better dispersion of cork and a solid interfacial bond between the cork particles and the PCL matrices as confirm by SEM. The Young's modulus values of the composites were little affected by a rate of 10% of fillers; but for higher loads, a significant decrease in this parameter was observed, resulting in more flexible materials. The treatment delayed thermal degradation. These attractive performances reveal that sustainable cork based materials proposed in this work could be a good alternative to traditional and could find applications in a number of domains.

THE ENVIRONMENTAL IMPACT OF AN ETICS LAYER: A CASE OF STUDY WITH LIFE CYCLE ASSESSMENT (LCA) FROM ENVIRONMENTAL PRODUCT DECLARATION (EPD) IN PORTUGAL

This paper is focused on LCA (Life Cycle Assessment) of specific product based on lime used in Portugal how a more sustainable solution for building construction. This product is decorative mineral render based on lime used as final layer to an External Thermal Insulation Composite System (ETICS) based on cork boards (ICB). The case under study presents as differentials the use of cork, a natural product that has Portugal as the largest supplier in the world and mortars with a greater amount of lime and less use of cement. This is an attempt to reduce the ecological footprint by the manufacturer. In this way, this article analyses the data provided in the Environmental Product Declaration (EPD) by the manufacturer, trying to establish a comparative impact reduction with other similar products.

Using field and nursery treatments to establish Quercus suber seedlings in Mediterranean degraded shrubland

Abstract: Cork oak (Quercus suber L.) is a suitable species for restoring Mediterranean ecosystems due to its capacity to resprout after wildfires and its economic importance for the use of cork. Several studies have focused on improving the seedling quality and abiotic conditions at the outplanting site to favour the field performance of Q. suber, however, most studies have been conducted by independently testing treatments. The aim of this study was to assess the combined effect of three techniques that focused on reforestation success with Q. suber in Mediterranean degraded shrubland: (i) a nursery technique to improve root system development, such as the use of deep containers to develop a longer tap root, combined with two field techniques such as (ii) the use of tree shelters to diminish solar radiation stress, and (iii) shrubland treatments to reduce competition for soil water and nutrients. For this purpose, 1-year-old Q. suber seedlings were grown in two containers types: a shallow container (CCS-18) and a deep container (CCL-30). Seedlings were established in a degraded shrubland at three experimental sites in the Calderona mountain range of Castellon, Spain. A factorial design was combined based on container type (CCS-18 and CCL-30), shrubland management (undisturbed shrubland and cleared shrubland in strips) and tree shelters (vegetable fibre tree shelters and no tree shelters). After 2 years of monitoring, the outplanting results indicated that using: (i) a deep container produced a longer taproot, but did not favour better survival or better field performance of seedlings; (ii) tree shelters improved the microweather conditions around seedlings, particularly by reducing excess incoming solar radiation; (iii) cleared shrubland strips reduced competition for soil water by favouring a higher water potential, better maximum photochemical PSII efficiency and higher survival rates for the seedlings established into cleared sites. The results indicate that the cleared shrubland treatment effects overlap the effects of using deep containers and tree shelters. This, in turn, reveals that shrubland clearing is the most suitable technique for favouring the introduction of a resprouter species like Q. suber into ecosystems characterized by predominantly degraded shrublands.

3D printed cork/polyurethane composite foams

Even though the production of 3D printed foams has already been widely studied, the main focus of the reports has been on their mechanical properties or their cushion behavior. In the present work a preliminary approach is made concerning the potential application of 3D printed PU foams for thermal applications with enhanced mechanical properties. For that propose, cork was used to enhance the properties of the resulting 3D printed composite foams. From the results obtained, it was observed that the addition of cork decreased the density and thermal conductivity of the ensuing foams. The stiffness of the ensuing composites was also reduced. Yet, the use of cork did not affect the thermal stability of the composites. Finally, the layer-to-layer bonding was evaluated and the results suggest that the addition of cork may not jeopardize the performance of the 3D printed PU foams. Besides their thermal insulation properties, the elastomeric behavior of the 3D printed foams produced may find applications that combine thermal insulation with damping properties. Furthermore, advances in the 3D printing technology may increase the range of applications of these foams.

Graphene-Enriched Agglomerated Cork Material and Its Behaviour under Quasi-Static and Dynamic Loading.

The use of cork for a variety of applications has been gaining significance due to environmental concerns and political agendas. Consequently, its range of applications is growing rapidly. In this work, aiming to improve its mechanical response for crashworthiness applications, cork agglomerates were enriched by small quantities of graphene oxide or graphene nanoplates in order to observe a resulting improvement of the mechanical behaviour during quasi-static and dynamic compressive loading cases. To produce homogenous cork agglomerates including graphene, the material was previously dispersed into granulated cork using stirrers to achieve a good distribution. Then, the typical procedure of compression and curing was carried out. Magnified images attest a good dispersion of graphene into the cork matrix. Mechanical testing was performed for a variety of graphene concentrations (0.1, 0.5 and 1.0 weight %), becoming clear that the beneficial effect of including graphene (either oxide or nanoplates) is related to a later densification stage while keeping the same stress plateau levels.

Somatic Embryogenesis of Quercus suber L. From Immature Zygotic Embryos.

Quercus suber L., cork oak, is a forest tree of high social and economic value. The cork is traditionally used in the wine industry to produce bottle stoppers, but it is also a very good material for both thermal and acoustic insulation in construction. Since its harvest does not harm the tree, the use of cork in the industry has a positive impact on the environment.Somatic embryogenesis is considered a feasible system for in vitro regeneration procedures, with many advantages in woody species. Classical genetic breeding programs have important limitations in forest trees, like cork oak, due to their long life span and difficulties of seed conservation and vegetative reproduction. Therefore, somatic embryogenesis has a great potential for large-scale propagation and cryopreservation of elite genotypes, as well as for transformation strategies. In the case of Q. suber, several in vitro propagation systems through somatic embryogenesis have been reported, with different efficiency rates.In the present chapter, updated information is reported about an efficient protocol for induction of somatic embryogenesis of Q. suber from immature zygotic embryos, as well as methods for proliferation and maturation of somatic embryos, germination, plantlet regeneration, and acclimatization.

Cork: Current Technological Developments and Future Perspectives for this Natural, Renewable, and Sustainable Material

Cork is the bark of Quercus suber L., the cork oak tree. It is currently explored for different industrial applications, of which stoppers for the wine industry is the most representative and economically important. During the processing stages, up to 30% of cork is transformed into powder, which is mainly used for energy production by the industry. This underexploited natural resource stream constitutes an opportunity for the development of new products. In this review, we discuss cork as a potential source of chemicals for alternative applications. Special emphasis is dedicated to (a) suberin, (b) the extractives fraction, and (c) the use of cork in nontraditional applications. Suberin constitutes a source of long chain hydroxyacids which can serve as building blocks for new macromolecules and materials. The structure and composition are briefly addressed, while the advances in suberin depolymerization, extraction methodologies, and the proposed applications for this material are thoroughly discussed. T...

Embodied carbon minimisation of retrofit solutions for walls

Energy saving in a building is mainly a function of the performance of building insulation and equipment. However, initial embodied carbon dioxide emissions increase as the operational energy decreases, so selecting the best energy retrofit solution should take this into account, together with building-specific needs. Currently there is no regulation of embodied carbon dioxide emissions in the European Union construction industry. The effectiveness of a low-carbon dioxide emission project should be judged by its energy in use together with the building-specific needs, not the total of the energy expended in its retrofit. Three different buildings with different occupant behaviours were studied, and five different retrofit solutions for the external rendering of walls were tested. The objective was to establish a relationship between the initial embodied carbon dioxide of a retrofit solution and the real operational energy consumed. A probabilistic approach was developed to predict the number of years that each solution takes to reduce the embodied carbon dioxide to 0·15 kg/kWh of operational energy in each building. The use of cork in mortars represents the most positive measure to reduce embodied carbon dioxide and increase energy efficiency.

Ultimate use of Cork – Unorthodox and innovative applications

In this survey the untraditional practical applications of cork is presented. High-quality goods with improved performances have been developed by those who came up with creative ideas and develop them. From several types of industries to private entrepreneurs, cork has been calling the attention of many creative minds over the last decade. From surfboards or designer clothes to an outstanding work of art made from cork has proved that this natural material becomes a noble feedstock not only for those who appreciate a good beverage and high-performance materials but also for those who look for sustainable products from natural sources. A general overview of cork composition, origin, and industry is also briefly disclosed.