Geopolymers - Design, Preparation, Applications

Concrete is the most commonly used construction material worldwide, and many efforts have been carried out in recent years to improve their functional properties trying to increase, in the meantime, its sustainability. Concrete’s environmental impact is well known, linked both to the space it occupies in landfills and its highly energy-intensive manufacturing, thus branding the cement industry one of the largest CO₂ emission sources. For this reason, both the sector industry and academy have devoted their studies to eco-sustainable materials able to maintain the specific properties of cements. Synthetic inorganic polymers based on aluminosilicate or phosphate have been recognized for almost twenty years now as geopolymers. Dissolved in a basic environment and prepared following a process known as geopolymerization, these materials are able to reach the chemical and mechanical properties of ceramic ones. Reactive inorganic raw materials, inert resources, and a geopolymeric resin are molded resulting in a composite with improved properties. Geopolymers can be exposed to high heat sources due to a great tolerance to high temperatures because they are non-combustible, do not develop gas or fumes, are not toxic, and do not explode as, contrary to traditional hydraulic cements, they do not contain water in their structure. In addition, they are eco-friendly and sustainable materials because waste and various kinds of industrial byproducts can be recycled as raw materials or inert fillers for their preparation at low processing temperatures, thus reducing production costs. In addition, these inorganic polymers have attracted growing attention because they have performances comparable to those of Portland cement but are able to reduce CO₂ emissions.

We cordially invite experts in the field of geopolymers to submit papers to this Special Issue.