Polymer Nanocomposites in Building,Construction

Nanotechnology is an enabling technology allowing to do new things in almost every conceivable area. Initial efforts to exploit nanoscience/nanotechnology development in the construction industry focused mainly on understanding phenomena and improving performance of existing materials. Recently, polymer nanocomposites started to be introduced in other areas like the construction industry.

Polymer nanocomposite field attracts considerable attention these days due to a variety of potential practical applications. They have offered a great opportunity in sustainable construction/green building application due to their efficiency and environmental protection. Their use in the construction industry is still less known outside the research area. This paper is a short review of recent studies done in this area, taking into account that some nano based materials are ready to be used by the construction industry. This review covers some studies done in the polymer nanocomposite applications in construction basic materials such as concrete, asphalt, thermal and sound insulation, adhesives, coatings, plastics and in energy.     

UN sustainable development goals: How can sustainable/green chemistry contribute? Green chemistry as a source of sustainable innovations in the cosmetic industry

Sustainable innovation is a key-objective for our Group that has recently integrated the principles of sustainable development into all stages of a product's life cycle, from its design to consumer use. The following ambitious commitment: 100% of its products should bring an environmental (or social benefit) by 2020, will be reached, in particular, by integrating and giving a constant privilege to renewable raw materials -or ingredients-that originate from sustainable resources that fully comply with the green chemistry rules. In this short review, integration of Green Chemistry principles by our Group, strategies to identify new performing ingredients through sustainable chemistry as well as illustrative examples of innovative raw materials will be presented. With regard to the crucial respect of the environment of our planet, sustainable chemistry has become an indispensable turning point for industrial groups highly devoted to innovation.     

Extraction of humic acid from biological matrix – dry cow dung powder

Abstract

The increased local and global concern, for alarming environmental pollution, offers incentives to explore new green and clean materials and methods for safeguarding the environment. The generation of benign alternate routes for any step in chemical processes, is the need for today and tomorrow. In the present work, humic acid (HA) has been extracted from a green source, “dry cow dung powder”, using simple, cost effective, and eco-friendly methods. HA has been extracted, isolated, and characterized by employing different spectroscopic methods. The process investigated herein imparts a boost to “Green Chemistry”, a promising solution to many global environmental problems.     

Are certified reference materials a victim of quality systems? The need for working matrix-certified reference materials

The use of natural matrix-certified reference materials by commercial environmental laboratories is increasing rapidly. These materials are now an essential component of the quality systems of most commercial environmental laboratories. The use is increasing faster than existing producers, principally government agencies, can meet. The use of data from well established laboratory proficiency schemes is shown to be one alternative way of producing natural matrix-certified reference materials designed for use as day-to-day within-batch control materials.     

Compositional characterization of encrustation on marble with laser induced breakdown spectroscopy

This study deals with the analysis of encrustation on marble by laser induced breakdown spectroscopy (LIBS), with the aim to obtain quick in-situ information on the in-depth profiling of the encrustation before advancing to conservation treatments. The encrustation examined is formed on exposed marble: (a) as products of the interaction between the stone surface and atmospheric pollutants (dendritic black and thin black encrustation, of approximately 300 and 200 μm thicknesses, respectively); (b) from deposition of soil–dust on marble surfaces (soil–dust crust, 300 μm thick); and (c) from treatments conducted in the past for aesthetic and/or protective purposes (patina samples, 300 μm thick). The crusts examined are multilayer encrustations on un-weathered marble, as revealed by studying cross sections with optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray analysis. The elemental LIBS profiles of black encrustation based on relative spectral line intensity values show that the Fe, Si, Al and Ti content relative to Ca content decrease significantly with depth, expressing, thus, contamination decreasing within the alteration layers, since these elements originate from atmospheric pollution and deposition. In the cases of soil–dust encrustation and patina samples Si I and Al I emissions identified throughout the analyzed crust, indicate deposition of soil–dust and remnants of previous treatments, respectively. Therefore, LIBS, a micro-destructive technique can be used as an autonomous in-situ diagnostic technique to obtain in-depth elemental profiling of encrustation even in cases of highly in-homogeneous layered crusts, such those of un-weathered Pentelic marble.     

The development of porcelain foams lighter than water for heat isolation application

In this study, technological and heat isolation properties of porous ultra-lightweight porcelain foams were investigated. Traditional construction materials such as brick show good durability against environmental conditions. Bricks are also a good alternative compared to pumice blocks and autoclaved aerated concrete which are largely used as construction materials. Bricks are also more economical than the other construction materials. But they also have poorer thermal insulation properties. Among the construction material, XPS shows the best heat isolation properties. XPS (extruded polystyrene foam) is a polymeric material. Although XPS shows best heat insulation property, it easily flames. The aim of this study is developing porous porcelain isolation materials lighter than water by using a replication method and relatively better thermal isolation properties than the other construction materials.

     

Waste marble dust-filled sustainable polymer composite selection using a multi-criteria decision-making technique

This research works with the optimal design of marble dust-filled polymer composites using a multi-criteria decision-making (MCDM) technique. Polylactic acid (PLA) and recycled polyethylene terephthalate (rPET)-based composites containing 0, 5, 10, and 20 wt% of marble dust were developed and evaluated for various physicomechanical and wear properties. The results showed that the incorporation of marble dust improved the modulus and hardness of both PLA and rPET. Moreover, a marginal improvement in flexural strength was noted while the tensile and impact strength of the matrices were deteriorating due to marble dust addition. The outcomes of wear analysis demonstrated an improvement in wear resistance up until 10 wt% filler reinforcement, after which the incidence of dust particles peeling off from the matrix was observed, thereby reducing its efficiency. The best tensile modulus of 3.23 GPa, flexural modulus of 4.39 GPa, and hardness of 83.95 Shore D were obtained for 20 wt% marble dust-filled PLA composites. The lowest density of 1.24 g/cc and the highest tensile strength of 57.94 MPa were recorded for neat PLA, while the highest impact strength of 30.94 kJ/m² was recorded for neat rPET. The lowest wear of 0.01 g was obtained for the rPET containing 5 wt% marble dust content. The experimental results revealed that for the examined criteria, the order of composite preference is not the same. Therefore, the optimal composite was identified by adopting a preference selection index-based MCDM technique. The findings demonstrated that the 10 wt% marble dust-filled PLA composite appears to be the best solution with favorable physical, mechanical, and wear properties.     

Characterization and Applications of Red Mud,an Aluminum Industry Waste Material,in the Construction and Building Industries,as well as Catalysis

The disposal of red mud (RM), a waste material generated by the aluminum industry, remains a global environmental concern because of its high alkalinity and smaller particle size, which have the potential to pollute air, soil, and water. Recently, efforts have been made to develop a strategy for reusing industrial byproducts, such as RM, and turning waste into value-added products. The use of RM as (i) a supplementary cementitious material for construction and building materials, such as cement, concrete, bricks, ceramics, and geopolymers, and (ii) a catalyst is discussed in this review. Furthermore, the physical, chemical, mineralogical, structural, and thermal properties of RM, as well as its environmental impact, are also discussed in this review. It is possible to conclude that using RM in catalysis, cement, and construction industries is the most efficient way to recycle this byproduct on a large scale. However, the low cementitious properties of RM can be attributed to a reduction in the fresh and mechanical properties of composites incorporating RM. On the other hand, RM can be used as an efficient active catalyst to synthesize organic molecules and reduce air pollution, which not only makes use of solid waste but also lowers the price of the catalyst. The review provides basic information on the characterization of RM and its suitability in various applications, paving the way for more advanced research on the sustainable disposal of RM waste. Future research perspectives on the utilization of RM are also addressed.     

Prepared and properties of filled and pozzolanic-filled cements from marble dust waste and granulated slag

Journal of Thermal Analysis and Calorimetry - Marble processing produces immense amounts of solid waste, which causes environmental issues. This work aims to “recycle marble dust waste”...     

An Assessment of Dust Analyses: With Particular Reference to Lead and Certain Other Metals

Abstract

The last few years have shown an increase in the number of publications describing studies on dust as indicators of environmental pollution, especially by trace metals. The techniques of sampling and analysis used in these studies are reviewed, with particular attention to inconsistencies and differences which make data incomparable. The need for work on the development of standard methods is demonstrated. Only by the application of good quality control, reference materials and reliable techniques will an unsatisfactory situation be improved.     

Pretreatments of wheat straw for possibility use in maintenance-free compressed green roof substrates

Green roofs are a key measure used to alleviate the urban heat island effect and reduce stagnant water from urban runoff. However, the expensive substrate material and high construction cost restrict the large-scale application of green roofs. Wheat straw (WS) contains abundant nutrients needed for plant growth; however, burning this straw waste causes severe environmental pollution. In this study, six pretreatment methods, including mixed, soaked, hydrothermal, ultrasonic, microwave, and steam explosion, and three liquid media, including deionized water, acetic acid, and wood vinegar, were used to treat WS to improve its properties and decrease its environmental pollution effects. The results showed that, compared to other treatments, physical methods (microwave, ultrasonic) used in conjunction with wood vinegar could effectively break down the particle structure of WS and increase porosity. Most of the crystallinities were reduced by 1.45–6.66% compared to WS when using these methods, and the absolute values of the surface zeta potential were reduced by 4.224.67 mV. Additionally, the contents of macromolecular lignocellulose, which is difficult to decompose, were reduced by 3.6613.75%. Compared with the use of deionized water or acetic acid, wood vinegar reduced the compressive force of the WS substrates and the energy consumption of compression. Hydrophilic groups such as hydroxyl were introduced into the WS to increase the water absorption rate. Overall, the microwave-assisted wood vinegar pretreatment was an effective method for improving the WS properties for use as a potential alternative substrate material in green roof construction.

     

Wooden-based materials: Eco-friendly materials for direct mass spectrometric analysis and microextraction

Lignocellulosic materials have arisen as a sustainable alternative in microextraction techniques during the last 10 years. As they are natural materials, their use fits into some of the principles of Green Analytical Chemistry. Their inherent porosity, narrow shape, and rigidity permit their use in ambient ionization mass spectrometry techniques. In particular, the combination of wooden-based materials and direct analysis gives birth to the so-called wooden-tip electrospray ionization mass spectrometry technique. This approach has been used for the direct analysis of complex samples, and as a streamlined tool for fingerprint quality analysis. Also, wooden-based materials can be superficially modified to boost the interaction with target compounds, allowing their isolation from complex samples. This review describes the potential and applicability of direct analysis using lignocellulosic materials, as well as other alternatives related to their use in microextraction.     

Ecofriendly Biocomposites from Natural fibers: Mechanical and Weathering study

Increasing environmental concerns and depletion of petroleum resources has forced researchers around the globe to find new green materials. In the present research work, a particular interest was focused on the effective use of lignocellulosic natural fibers as reinforcement using polymer resin as a novel matrix. Green composites were prepared using the compression molding technique with different fiber contents. The physicomechanical and thermal characteristics of the different composite samples were investigated as a function of fiber contents. The results obtained suggest that the properties of the polymer matrix are positively affected by the incorporation of natural cellulosic fibers.     

The impact of time on the heat resistance of self-compacting high-performance concrete incorporated with recycled martials

The influence of time on the mechanical behavior of concrete after exposure to elevated temperatures has been studied. Twenty-one self-compacting high-performance concrete mixtures with different incorporation amounts of coarse recycled concrete aggregate (RCA) and three unprocessed waste powder materials have been tested at age of 270 days for residual compressive and flexural strength after exposure to fire. The results have been compared to the results for the same concrete, which have been studied at age of 90 days. A new parameter has been introduced for comparing the responses of concrete to elevated temperatures at different ages; this parameter was the “heat resistance” which expresses the total area under the curve of the relative residual strength (compressive or flexural) after exposing to six temperature degrees (20, 150, 300, 500, 600, and 800 °C). The results showed that the age of concrete has an influence on the response of concrete to elevated temperatures. The heat resistance of compressive strength enhanced with age but the concrete behaved with a tendency different to that at the age of 90 days. The heat resistance of flexural strength has not been affected or slightly decreased but not with more than 10% to that at the age of 90 days. The used waste powder materials were unprocessed waste fly ash, waste cellular concrete powder and waste perlite powder; they proved that using any of them up to 15% as a replacement for cement with 0% or 25% of RCA enhanced the concrete resistance for the fire with time. The main two reasons for changing of residual strength with the time were the changing of water content and the proceeding of hydration of the binder. In general, long ages testing properties of concrete simulate the real behavior of concrete structures accurately.

     

Evaluation of Properties of Concrete Without Cement Produced Using Fly Ash-Based Geopolymer

The use of ordinary Portland cement (OPC) in the construction industry is inevitable. The huge production of OPC and its use in infrastructural development pose an environmental impact. Greenhouse gas emitted increases the global temperature and it is an alarming sign to everybody on the planet. Concrete is the most consuming material which is produced by using OPC and it is proven that OPC contributes a lot to CO₂ emission. Hence in this study attempt is made to produce concrete by using environment-friendly material like fly ash along with alkaline activators, which is termed Geo polymer concrete. The by-product fly ash is widely available worldwide. It is a by-product of thermal power plants. The use of fly ash in concrete produces less expensive and more cost-effective concrete than concrete made up using OPC. Due to its high silicate and alumina content, fly ash reacts with an alkaline solution to create an aluminosilicate gel that binds the aggregate and results in high-quality concrete. Fly ash is finer than cement, it occupies the pores of cement after hydration. This would result in denser concrete which gives higher strength. In comparison to ordinary concrete, fly ash-based geopolymer concrete offers better resistance to aggressive environments and high temperatures. In the present study, an alkaline activator of molarity 8 is used to prepare geopolymer concrete. The test specimens are cast and cured for 28 days. Test results indicate that an alkaline liquid fly-ash ratio (0.4) produces higher mechanical properties. Hence, geopolymer concrete produced in this study is found to be cost-effective and environment friendly.     

环境污染是化学惹的祸吗

人们总是将环境污染与化学连在一起,并认为化学是环境污染的根源。本文在分析环境污染的产生、化学在环境保护方面的作为的基础上认为,产生环境问题的根源主要是人类对自然无节制的索取和向环境超量排放废弃物以及没有充分利用化学科学的力量根治源头。     

Polymeric Macro-Molecular Piezoelectric Sensors for Evaluation of Structural Damage

Finding damages and their prevalence in structures is a very challenging problem. In order to identify potential structural damage, non-destructive methods are not very helpful. One of the most popular piezoelectric ceramic materials used worldwide is macromolecular lead zirconate titanate (PZT), also known as Pb[Zr(x)Ti(1-x)]O3. PZT transducers are proving to be a successful alternative for assessing the structure's health. The Macro-molecular PZT's self-actuating and sensing properties are utilized by the electromechanical impedance (EMI) method. In this capacity, the macro-molecular PZT patches serve as co-located actuators and sensors and make use of ultrasonic vibrations to produce a distinctive admittance “signature” of the structure. PZT patches perform exceptionally well in terms of damage sensitivity. The higher modes of vibration are locally activated by the local application of an AC source on the PZT transducers attached to the host structure. The alteration of the admittance response is a sign of injury to the transducer's vicinity. In the current study, the damage percentage and its location in a 150 × 150 × 150 mm concrete cube are being examined. Regression analysis is also used to determine the concrete cube's strength. This method also can identify hair-like cracks at an early stage, which explains how it can shield the building from serious failures.     

Decontamination of radionuclides on construction materials

A wide variety of materials can become contaminated by radionuclides, either from a terrorist attack or an industrial or nuclear accident. The final disposition of these materials depends, in large part, on the effectiveness of decontamination measures. This study reports on investigations into the decontamination of a selection of building materials. The aim has been to find an effective, easy-to-use and inexpensive decontamination system for radionuclides of cesium and cobalt, considering both the chemical and physical nature of these potential contaminants. The basic method investigated was surface washing, due to its ease and simplicity. In the present study, a basic decontamination formulation was modified by adding isotope-specific sequestering agents, to enhance the removal of cesium(I) and cobalt(II) from such construction materials as concrete, marble, aluminum and painted steel. Spiking solutions contained ¹³⁴Cs or ⁶⁰Co, which were prepared by neutron activation in the SLOWPOKE-2 nuclear reactor facility at the Royal Military College of Canada. Gamma spectroscopy was used to determine the decontamination efficiency. The results showed that the addition of sequestering agents generally improved the radiological decontamination. Although the washing of both cesium and cobalt from non-porous materials, such as aluminum and painted steel, achieved a 90–95 % removal, the decontamination of concrete and marble was more challenging, due to the porous nature of the materials. Nevertheless, the removal efficiency from 6-year-old concrete increased from 10 % to approximately 50 % for cobalt(II), and from 18 to 55 % for cesium(I), with the use of isotope binding agents, as opposed to a simple water wash.     

Provenance studies of the white marble of the cathedral of Como by neutron activation analysis and data reduction

Marble samples from major Italian quarries and from the Como Cathedral were analyzed for their trace element content, which is indicative of their provenance. Ca, Sc, Cr, Mn, Fe, Co, Rb, Sb, Cs, Ba, La, Ce, Sm, Eu, Gd, Ho, Tm, Yb, Lu, Hf, Th and U elements were determined by neutron activation analysis. Results as well as their precision and accuracy are presented and discussed. Data treatment has allowed to characterize the marble quarries on the basis of their trace element content, to identify the provenance of the marble used in the Como Cathedral and to show differences in the element distribution of new and weathered marble samples from the same quarry.     

Process design for integration of extraction,purification and formulation with alternative solvent concepts

Methods of Green Chemistry are in the meantime established in process design for extraction of natural products [1]. Moreover, natural products do have the inherent societal benefit of being a priori bio-degradable and therefore do not cause any additional waste-water and recycling problems in hospitals, cities and municipalities or environmental enrichment [2].Nevertheless, those inherent benefits could be easily compromised if they are not combined with the design and operation of fully integrated processes in manufacturing. One isolated action of Green Chemistry is not sufficient to gain the entrepreneurial balance of economy and ecology with competitive manufacturing, new marketable products, and sustainability. While any process modification could be implemented in substituting simply one existing step, a fully integrated new process needs to be set up to exceed the existing benchmark or best practice and to be transferred into manufacturing.Finding alternative solvents and enhancing mass transfer in extraction need to be integrated. This integration into a complete process from extraction over purification to formulation, considering recycling at all steps, is a complex task which could not be fulfilled on a purely experimental basis. The efforts would be too high and costly. Therefore, the paper reviews the existing status shortly and exemplifies based on a case study, choosing 10-deacetylbaccatin III as a typical example, a theoretical approach in thermodynamics and process modeling, and how they can contribute to an alternative process design. Still, these steps in conceptual process design and basic engineering seem to be the major challenge in industrial acceptance of alternative ideas.The authors have described the transfer into innovative manufacturing concepts already elsewhere [1], [2], [3].