Impact of Nanomaterials in Biological Systems and Applications in Nanomedicine Field

The increasingly widespread use of engineered nanomaterials in many applications increases the need to understand the mechanisms behind their toxicity [...]

A review of moisture buffering capacity: from laboratory testing to full-scale measurement

It is important to control indoor humidity level in buildings as it influences occupant’s health and comfort. Hygroscopic building materials present great potential to passively regulate air humidity due to their ability to adsorb and desorb moisture. In recent years researchers have focused on this capacity, referred to as Moisture Buffering, as it has the potential to improve indoor thermal comfort and reduce HVAC usage and their consequent energy consumption. However, building designers generally do not consider this property an important factor, due to its unclear influence and difficulty in the quantification of its effects in real buildings. Therefore, it is complicated to develop an appropriate laboratory scale testing. The aim of this paper is toinvestigate the challenges related to moisture buffering measurement and to examine the approaches adopted by researchers. The significance of this study is to identify discrepancies between existing methods in the evaluation of the dynamic adsorption properties and presents areas for further development in testing

A review of moisture buffering capacity: from laboratory testing to full-scale measurement

It is important to control indoor humidity level in buildings as it influences occupant’s health and comfort. Hygroscopic building materials present great potential to passively regulate air humidity due to their ability to adsorb and desorb moisture. In recent years researchers have focused on this capacity, referred to as Moisture Buffering, as it has the potential to improve indoor thermal comfort and reduce HVAC usage and their consequent energy consumption. However, building designers generally do not consider this property an important factor, due to its unclear influence and difficulty in the quantification of its effects in real buildings. Therefore, it is complicated to develop an appropriate laboratory scale testing. The aim of this paper is toinvestigate the challenges related to moisture buffering measurement and to examine the approaches adopted by researchers. The significance of this study is to identify discrepancies between existing methods in the evaluation of the dynamic adsorption properties and presents areas for further development in testing

The moisture buffering performance of plasters when exposed to simultaneous sinusoidal temperature and RH variations

Wall constructions have the capacity to contribute to the passive regulation of indoor Relative Humidity. This property, referred to as moisture buffering, is linked to the hygroscopicity of materials, which allows materials to store and release moisture from and to the surrounding air, depending on the indoor Relative Humidity levels. Laboratory testing procedures, based on a step-response method, were introduced to quantify moisture buffering. The step response method monitors the change in mass of samples, when subjected to square wave humidity variation and constant temperature. However, those protocol's prescribed testing environmental conditions may not be representative of the materials behaviour in buildings, as the surface of walls is exposed to an indoor environment that changes with respect to the temperature and humidity daily and seasonally.This paper investigates the response of clay and gypsum plasters to quasi sinusoidal and simultaneous humidity and temperature functions. It was experimentally shown that the relative humidity influences the amount of water vapour adsorbed and desorbed by the materials, while temperature impacts the rate and the time lag response of clay and gypsum to the indoor humidity variation. The significance of the investigation is to demonstrate the joint effects of Relative Humidity and temperature on hygroscopic materials and to seek to developing a laboratory test, which can represent the real behaviour of such materials in buildings, which are exposed to sine wave-forms

Inorganic Nanomaterials versus Polymer-Based Nanoparticles for Overcoming Neurodegeneration

Neurodegenerative disorders (NDs) affect a great number of people worldwide and also have a significant socio-economic impact on the aging population. In this context, nanomedicine applied to neurological disorders provides several biotechnological strategies and nanoformulations that improve life expectancy and the quality of life of patients affected by brain disorders. However, available treatments are limited by the presence of the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (B-CSFB). In this regard, nanotechnological approaches could overcome these obstacles by updating various aspects (e.g., enhanced drug-delivery efficiency and bioavailability, BBB permeation and targeting the brain parenchyma, minimizing side effects). The aim of this review is to carefully explore the key elements of different neurological disorders and summarize the available nanomaterials applied for neurodegeneration therapy looking at several types of nanocarriers. Moreover, nutraceutical-loaded nanoparticles (NPs) and synthesized NPs using green approaches are also discussed underling the need to adopt eco-friendly procedures with a low environmental impact. The proven antioxidant properties related to several natural products provide an interesting starting point for developing efficient and green nanotools useful for neuroprotection

AFM Characterization of Halloysite Clay Nanocomposites’ Superficial Properties: Current State-of-the-Art and Perspectives

Natural halloysite clay nanotubes (HNTs) are versatile inorganic reinforcing materials for creating hybrid composites. Upon doping HNTs with polymers, coating, or loading them with bioactive molecules, the production of novel nanocomposites is possible, having specific features for several applications. To investigate HNTs composites nanostructures, AFM is a very powerful tool since it allows for performing nano-topographic and morpho-mechanical measurements in any environment (air or liquid) without treatment of samples, like electron microscopes require. In this review, we aimed to provide an overview of recent AFM investigations of HNTs and HNT nanocomposites for unveiling hidden characteristics inside them envisaging future perspectives for AFM as a smart device in nanomaterials characterization

Comparison of moisture buffering properties of plasters in full scale simulations and laboratory testing

The regulation of indoor relative humidity is a key factor for the provision of occupant health and comfort. Passive humidity regulation is possible if porous materials, for example clay and gypsum plasters, are exposed to the indoor environment. Materials that are highly hygroscopic can help regulate relative humidity levels through their capacity to adsorb and release water vapour from and to the indoor air via a dynamic process referred to as moisture buffering. Laboratory test methods have been developed to measure this moisture buffering capacity, which are well-suited for comparative testing of relatively small material samples under controlled conditions. However, quantification of the impact of hygroscopic materials in real buildings requires additional evaluation, like field testing and the support of simulation models, which can successively be used for the development of new protocols capable of giving information about materials’ moisture buffering performances indoors. This paper investigates moisture buffering capacity of three hygroscopic plasters (clay, gypsum and lime), and compares measurements obtained in the laboratory to those from numerical simulations of a single-zone room space. The dynamic sorption capacity of the plasters was investigated using the NORDTEST protocol and results compared to those from hygrothermal simulation. Differences are identified between the two methods in the quantification of the moisture buffering potential, which lead to further investigation on the effect of ventilation and moisture transport through the entire wall assembly. The significance of this paper is to show building moisture regulation involves also different factors, such as ventilation and walls moisture transport, which will impact the moisturebuffering potentials indoors. Consequently, it is necessary to better understand moisture buffering in real buildings, to quantify the influence of hygroscopic materials indoors, and introduce alternative laboratory testing, to give quantitative information about their impact in buildings.<br/

Hygrothermal analysis of technical solutions for insulating the opaque building envelope

Abstract The application of insulating materials for energy refurbishment of buildings improves the thermal transmittance of the envelope. However, if not properly planned and realized, it could reduce the wall's drying potential, modifying its original features and leaving it generally more humid. This can lead to moisture damages, humid insulation material and risk of mould growth. To avoid any problem related to the increased presence of water in the building envelope, it becomes therefore essential to perform the so-called hygrothermal assessments. In this regard, the international standards offer, beside the traditional Glaser method based on the mere vapour transport, the use of dynamic hygrothermal simulations. These allow to simultaneously consider the transport and storage of heat and moisture in building materials, the influence of climate (including rain and solar radiation in different locations), user behaviour and initial conditions. The aim of this paper is to compare Glaser and dynamic methods and to highlight their advantages and disadvantages, considering the different approaches to the evaluation not only of superficial and interstitial condensation, but also of durability, considering biological attack, freeze/thaw cycles, corrosion, etc