Response of colour and hygroscopic properties of Scots pine wood to thermal treatment

The effect of heat treatment on the surface colour and hygro- scopic properties of pine wood were investigated in this study. Boards of Scots pine wood （Pinus sylvestris L.） were subjected to thermal treatment at 200℃, for 4, 6, and 8 h. The change of equilibrium moisture content and density values of the specimens in order to facilitate the understand- ing of the treated material behavior. The colour parameters L＊ a＊ and b＊, used to depict the total colour change （dE） of wood surface, were shown to change proportionally to the treatment intensity. Moreover, swelling in the tangential and radial directions and absorption of the specimens ap- peared to be enhanced in great extent by the thermal treatment process. The mean value of swelling percentage in the tangential direction de- creased 10.26%, 17.22%, and 19.60% for specimens treated for 4, 6, and 8 h, respectively, referring to the final measurement after 72 h of immer- sion. In radial direction, mean value of swelling percentage decreased 19.56%, 32.75%, and 34.65% for treated for 4, 6 and 8 h, respectively, after 72 h immersion, which attests the decrease in swelling and im- provement in the hygroscopic behavior of Scots pine wood.

Effects of Chemical Treatment on the Physical Properties of Typha

Plant-based concretes are produced from plant aggregates and a binder.Plant fibers are mainly composed of saccharides(sugars)and these sugars can decrease the concentration of Ca2+ions in the cement pore solution and delay the formation of hydration products.To improve the interfacial bond between fibers and matrix a chemical treatment is widely used.This study investigates the effect of sodium hydroxide treatment on physical and hygroscopic properties of Typha aggregates.In particular,a 5%sodium hydroxide solution is used to treat these aggregates and their bulk and absolute densities,porosity,water content and water absorption are evaluated accordingly.Results indicate that bulk and absolute densities increase after treatment from 56.44 kg/m^(3) to 122.57 kg/m^(3) and 541.93 kg/m^(3) to 555.17 kg/m^(3),respectively.NaOH treatment reduces porosity of Typha from 89.58%to 77.92%and decreases water content from 1.4%to 1%.The treatment with sodium hydroxide reduces substantially the water absorption of the aggregates.

Hygroscopicity and optical properties of alkylaminium sulfates

The hygroscopicity and optical properties of alkylaminium sulfates （AASs） were investigated using a hygroscopicity tandem differential mobility analyzer coupled to a cavity ring-down spectrometer and a nephelometer. AAS particles do not exhibit a deliquescence phenomenon and show a monotonic increase in diameter as the relative humidity （RH） ascends. Hygroscopic growth factors （GFs） for 40, 100 and 150 nm alkylaminium sulfate particles do not show an apparent Kelvin effect when RH is less than 45%, whereas GFs of the salt aerosols increase with initial particle size when RH is higher than 45%. Calculation using the Zdanovskii-Stokes-Robinson mixing rule suggests that hygroscopic growth of triethylaminium sulfate-ammonium sulfate mixtures is non-deliquescent, occurring at very low RH, implying that the displacement of ammonia by amine will significantly enhance the hygroscopicity of （NH4）2SO4 aerosols. In addition, light extinction of AAS particles is a combined effect of both scattering and absorption under dry conditions, but is dominated by scattering under wet conditions.

3D extrusion of multi-biomaterial lattices using an environmentally informed workflow

The conventional building material palette has been proven limited in terms of adaptability to our current environmental challenges. Innovations in computational design and digital manufacturing have supported the broadening of biomaterial applications as an alternative. While biomaterials are characteristically responsive to stimuli such as temperature and humidity, their unpredictable behaviour is a hurdle to standardization and architectural utilisation. To examine the nexus between material formulation, computation and manufacturing, multi-biomaterial lattice structures were produced through an environmentally informed workflow. Customized biomaterial development resulted in three candidate biopolymer blends with varying levels of hydro-responsiveness and transparency. The computational strategy included a machine learning clustering algorithm to customise results and dictate material distribution outputs. To test the workflow, environmental data of solar radiation exposure and solar heat gain from a specific location was used to inform the material deposition via pneumatic extrusion for the design and digital fabrication of a deformation-controlled prototype of 350 mm × 350 mm. This led to a series of multi-biomaterial wall panel components that can be applied at architectural scale. In future, these techniques can support the incorporation of living elements to be embedded within the built environment for truly animate architecture.