A REVIEW OF SUSTAINABILITY ASSESSMENT OF SMART MATERIALS: THAT EXCHANGE ENERGY

Developments in building materials have been achieved with the aim of providing differentfunctions, increasing comfort, and providing solutions to economic and ecological problems. Inaddition to traditional materials, building materials have diversified with the use of compositematerials and sustainable/modern materials. The concept of smart material is defined as the abilityto perceive and react to environmental stimuli. From an architectural perspective, smart materialsrespond to environmental stimuli by adapting to environmental conditions. With this approach, itincludes building elements or components designed using smart materials.When a particular material is in energy balance with its environment, it is in equilibrium withoutany exchange of energy. Energy exchange occurs when the material has a different energy state.A potential emerges that leads to energy exchange. All energy-exchanging materials containatomic energy levels. The input energy raises the level, while the output energy returns the levelto the ground state.All materials, traditional and smart, need to save energy, and therefore, with the input or additionof energy, the energy level of the material increases. The increase in energy usually occurs byincreasing the internal energy of the material as heat. Smart materials that exchange energy havethe ability to recover internal energy in a more useful way. These materials can often convertenergy into a different output energy, such as electricity or light, rather than heat. Smart materialsthat exchange energy are divided into three different categories: light-emitting, electricitygenerating,and energy-storing materials.Light-emitting smart materials refer to materials or products in which molecules are excited by theeffect of energy and are temporarily at high energy levels. These materials have the ability to emitlight, for example, under the influence of light or an electric field. This process occurs when theenergy levels of molecules temporarily increase and then separate. Some of the absorbed energyis emitted as visible electromagnetic radiation. This optical emission phenomenon is calledluminescence. Light-emitting smart materials can be differentiated according to their triggerstimuli: photoluminescence and electroluminescence. Due to their high efficiency, these materialsare preferred in the field of architecture today.Electricity-generating smart materials refer to materials and products that can generate electricalcurrent in conjunction with a consumer in response to stimuli such as light, temperature orpressure. These materials may differ depending on the triggering stimuli.Energy-storing smart materials include materials and products that can store latent forms ofenergy, such as light, heat, electricity, or hydrogen, and have some degree of reversibility. Thesematerials can be separated depending on the triggering stimuli. Smart materials that store heat arepreferred in the field of architecture today.

A REVIEW OF SUSTAINABILITY ASSESSMENT OF SMART MATERIALS: THAT EXCHANGE ENERGY Keywords:

Energy efficiency , Building physics , Smart Materials , Exchange Energy Materials