Temperature Range Of Phase Transition Research Articles

Doping-mediated thermal control of phase transition for supersensitive ratiometric luminescence thermometry

Intelligent luminescent materials, characterized by optical switching in response to thermal stimulation, are highly attractive for cutting-edge temperature sensing technologies. However, the exploration of sensitive and reliable thermometric materials remains challenging. Herein, we establish a phase-transition-driven thermometric model that relies on the reversible transition between the monoclinic (β) and tetragonal (α) phase of LiYO2:Dy3+ crystals under controlled thermal stimulations. Accordingly, the ratiometric emissions from hypersensitive electric diploe transitions (4F9/2 → 6H13/2) drastically varied across the phase-transition temperature range, rendering remarkable thermal sensitivity and resolution (Sr-max = 35.24% K−1, δTmin = 0.009 K). We further demonstrate the extended control of phase-transition temperature and thermal hysteresis by a partial substitution approach. These findings highlight an endogenic approach to constructing customized luminescence thermometers via local crystal-field engineering, which raises new possibilities for practical sensing applications.

Investigation of the Positive Temperature Coefficient Resistivity of Nb-Doped Ba0.55Sr0.45TiO3 Ceramics

The demands of low-Curie-temperature (~−10 °C) positive temperature coefficient (PTC) thermistors are increasing in advanced precision integrated circuits and other industries. In this paper, the Nb-doped Ba0.55Sr0.45TiO3(BST)-based PTC resistivity materials are reported. The effects of the sintering process, especially the cooling rate on the PTC properties of the material, are investigated. The results indicate that the Ba0.55Sr0.45Ti0.9985Nb0.0015O3 composition of the prepared PTC ceramics demonstrates promising PTC characteristics. These include a Curie temperature as low as −13 °C, a high temperature coefficient of 0.296 at −3.4 °C, a large enough resistivity change of 3.1 over a narrow phase transition temperature range of approximately 38 °C, and moderate resistivity below the Curie temperature. Such properties suggest that the Ba0.55Sr0.45Ti0.9985Nb0.0015O3 ceramics are likely suitable for use in thermal management systems designed for low-temperature control.

Anomalous enhancing effects of electric pulse treatment on strength and ductility of TC17 linear friction welding joints

Mechanical properties of TC17 titanium alloy undergo a significant reduction after linear friction welding (LFW), of which the strength and ductility are hard to be improved simultaneously by traditional aging heat treatment (AHT), seriously limiting the application of LFW in the manufacturing of TC17 titanium alloy blisks. To this end, the present work proposes to use electric pulse treatment (EPT) to enhance the strength and ductility of TC17 LFW joints simultaneously by improving its microstructure. The results show that, in comparison to the uneven distribution of α phases in the welding zone (WZ), heat-affected zone (HAZ), and base metal (BM) zone after AHT, EPT can selectively homogenize the α phase distribution of WZ and HAZ without impacting the BM. The selective effect of EPT is reflected as the synergistic influence of the local Joule heating effect and the electron wind effect, which promotes the diffusion of β phase stabilizing element Mo and leads to a competitive precipitation of β phase and α phase in the α phase transition temperature range. The ratio of α phase to β phase in the WZ and HAZ finally approaches an equilibrium point which is similar to that of BM, leading to a uniform distribution of α phase and realizing the synergy of strength-ductility of LFW joint: the maximum strength increase observed is 12.9 %, accompanied by a corresponding elongation increase of 122 % (by AHT & EPT), and the maximum plasticity improvement is 185 %, accompanied by a corresponding strength increase of 4.3 % (by EPT for 1 h). This study provides essential insights for improving the strength and ductility of LFW TC17 titanium alloy blisks and enhancing the applications of LFW in aeroengine components.

A Study of a Cryogenic CuAlMn Shape Memory Alloy

In extreme temperature environments, a newly emerging engineering application involves both the active and passive control of structures using cryogenic shape memory alloys, which are smart materials able to recover high deformation below the freezing point. With the objective of carrying out new advances in this area, the present work aims to investigate the Cu-7.5Al-13.5Mn (wt.%) shape memory alloy. Thermal, microstructural, and thermomechanical analyses of as-cast and hot-rolled specimens were performed, taking into account the effects of annealing and solubilization. It was observed that the phase transition occurs at temperatures below 120 K and changes according to the thermo-mechanical path. Specifically, hot-rolling lowers the phase transition temperature range with respect to the as-cast condition–from 34 K to 23 K for Mf, and from 89 K to 80 K for Af. Additionally, when the annealing temperature rises, the phase transformation temperature increases as well, and the alloy loses its cryogenic features when heat treated above 473 K. Finally, loss factors of 0.06 and 0.088, which were respectively found in dynamic and static settings, validate the material’s good damping response.

Preparation and characterization of polyurethane/lauric acid-stearic acid as form-stable phase change materials with a wide phase transition temperature range

The current study employed a solvent-free method to prepare a series of crosslinked polyurethane/lauric acid-stearic acid composite form-stable phase change materials (FSPCMs). FTIR, SEM, and XRD results collectively indicate that lauric acid (LA) and stearic acid (SA) have been successfully adsorbed into the polyurethane (PU) mesh-like structure, maintaining their respective crystalline characteristics and exhibiting good compatibility. DSC and TGA data show the wide phase transition temperature range of FSPCMs from 39.6 °C to 70.0 °C, with decomposition commencing at 190.4 °C and the latent heat of FSPCM reaching 181.9 J/g. In conclusion, the broad phase transition temperature range and high latent heat of FSPCMs make them particularly suitable for thermal energy storage.

Influence of high-pressure heat treatment on magnetocaloric effects and magnetic phase transition in single crystal Gd3Ga5O12

The magnetic properties and critical magnetic phase transition critical behavior of Gd3Ga5O12 single crystals subjected to high-pressure heat treatment were investigated. The results show that high-pressure heat treatment reduces the Curie temperature and magnetization of the sample. Under a magnetic field change of 5 T, the maximum isothermal magnetic entropy of the sample is approximately 19.73 J/(kg·K). High-pressure heat treatment increases the phase transition temperature range and leads to an increase in the magnetic refrigeration power. Both Gd3Ga5O12 single crystals and the high-pressure heat-treated sample undergo a second-order phase transition. The critical behavior of the samples aligns with the mean field model acquired via critical model fitting. This indicates that the samples exhibit long–range exchange interactions in the system near the Curie temperature. Thus, this material can be used as a magnetic refrigerant for low-temperature applications.

The spider web of modified wheat bran captured PEG to form stabilized phase change composites for temperature regulation and waste heat storage

Biomass based phase change composites (PCCs) have potential application prospects in the field of thermal energy storage (TES). Environmentally friendly development could be realized by recycling and reusing wheat bran (WB) of the agricultural and forestry waste. Distinguished from conventional biomass derivatives and/or carbonization methods, multi-walled carbon nanotubes (MWCNT/OH) modified wheat bran aerogels (MWB) with 3D entanglement structure was fabricated by utilizing physical pasting incorporating chemical cross-linking and functional modification, and then followed by freezing method. The fabricated MWB exhibited a graded and “spider web” entangled special porous structure, which could adsorb polyethylene glycol (PEG) effectively to form stabilized PCCs (MWB/PEG). This non‑carbonized, thermally conductive biomass PCCs play a positive role in energy and environmental recycling. Experimental results indicated that MWB possessed 87.9 % adsorption efficiency and excellent anti-leakage property. Enthalpy efficiency embodied through thermal storage capacity reached 86.5 %. Besides, the outstanding temperature regulation and heat transfer characteristics were verified by thermal infrared imaging. Two clear phase transition buffers appeared as well as the temperature distribution mainly concentrated in the phase transition temperature range from vertical view during heating/cooling process. Thermal conductivity and thermal diffusion coefficient of MWB/PEG increased to 0.26 W/m·K and 0.19 mm2/s from 0.15 W/m·K and 0.11 mm2/s for pure PEG, respectively. The MWB/PEG could store thermal energy by illumination and corresponding photothermal conversion rate reached up to 80.4 %. This composite showed a remarkable waste heat storage and/or reuse through electrothermal testing with integrated conductive fabrics, which would provide a potential development of green and high performance of TES technology in wearable flexible sensors and other fields.

Synthesis and characterization of long‐chain (C20 ~ C48) fatty acid amides (FAAms) from soybean oil and alkyl amines for phase change material applications

AbstractBio‐based organic phase change materials (PCMs) have drawn attention considering their great value in environmental sustainability as a latent heat storage strategy. In this study, bio‐based fatty acid amides (FAAms) were synthesized directly from soybean oil and different amines through a solvent‐free reaction with a non‐toxic catalyst (DABCO). The chemical and thermal properties were confirmed by FT‐IR, NMR, DSC, and TGA measurements. The effects of oil saturation and chain length were investigated. FAAms were successfully synthesized from most of the primary alkyl amines with high purity and yield. Fifteen different FAAms exhibit high latent heat (up to 202 J/g) with a single‐phase transition peak. A general trend of increasing enthalpy of fusion, narrower phase transition temperature range, higher melting temperature, and better thermal stability was found with increasing FAAms chain length. An opposite trend was observed for some long‐chain FAAms (C > 42). Overall, a wide choice of green, organic PCMs with comparable thermal properties to petroleum based PCMs is provided in this work. Those FAAms with high working temperatures (>100°C) could expand the application of organic PCM to different fields such as steam generation, textile, rubber industry, etc.

Novel star-shaped liquid crystal macromolecules based on conjugated structures of azo and Schiff bases: synthesis and properties

ABSTRACT In this paper, a series of novel liquid crystal units (ASE-n, n = 4, 6, 8) of azo Schiff bases with sulphonic acid (-SO3H) as terminal substituents and different alkyl chain lengths were designed and synthesised. Nine star-shaped liquid crystal macromolecules with different central groups (ASE-P-n, ASE-T-n, ASE-G-n, n = 4, 6, 8) were synthesised by esterification of three novel azo Schiff base liquid crystal units (ASE-n, n = 4, 6, 8) with phloroglucinol, pentaerythritol and glucose. The structure of the synthesised compounds were analysed by infrared spectroscopy and 1H NMR. The results showed that all the compounds were consistent with the molecular structure design. The properties of liquid crystal such as phase transition temperature and liquid crystal mesophase range were characterised by POM and DSC. The effects of alkyl chain length and branched degree on the properties of liquid crystal were studied. The maximum absorption spectrum of the compound was determined by UV-Vis spectrophotometry. The photoisomerisation reaction of the compound was also studied. Under ultraviolet light (λ = 365 nm) irradiation, the effect of different duration on the cis-absorption percentage of azo (-N=N-) bond in the compound was studied.

Excellent strain properties in (K,Na)NbO3-based piezoceramics induced by lamination composite strategy

To reconcile the contradiction between piezoelectric property and its temperature stability, the preparation of composite piezoceramics using multiple components has become an emerging direction. Herein, (K,Na)NbO3-based piezoceramics are adopted to prepare high-performance laminated composite ceramics inspired by the lamination composite strategy, and sintered in the reducing atmosphere to meet the development of multilayer piezoelectric actuators with base metal internal electrodes. By adjusting the composition ratio, a high inverse piezoelectric coefficient d33* of 1065 pm/V (@ 2 kV/mm) is obtained in the two-component composite ceramics, which fluctuated less than ± 6% in the range of 25–160 °C. In the three-component composite ceramics, a higher d33* value of 1326 pm/V (@ 2 kV/mm) is achieved and maintained > 90% until 150 °C. The electric-field-induced strain performances of laminated composite ceramics significantly exceed those of their basic components, which is related to the piezoresponse gain provided by the internal interfaces. The excellent temperature stabilities come from the more diffused phase transition temperature range formed by the complementation of multiple components. The combination of ultrahigh strain performance, high temperature stability, and good fatigue resistance, together with sintering in the reducing atmosphere, constitutes an important step to promote the application of (K,Na)NbO3-based multilayer piezoelectric actuators.

The microstrain-accompanied structural phase transition from h-MoO3 to α-MoO3 investigated by in situ X-ray diffraction.

In situ X-ray diffraction indicates that the structural phase transition from h-MoO3 to α-MoO3 is a first-order transition with a phase transition temperature range of 378.5-443.1 °C. The linear coefficients of thermal expansion of h-MoO3 are strongly anisotropic, that is, αa=b = 72.87 × 10-6 K-1 and αc = -19.44 × 10-6 K-1. In the h-MoO3 phase, water molecules are located at the (0 0 0.25) site inside the MoO6 octahedra tunnel that is formed by six MoO6 corner-sharing octahedron zigzag chains. With increasing temperature, the release of water molecules from the octahedra tunnel causes the octahedra chains to shrink and the octahedra tunnel to expand. When the phase transition occurs, the anomalous expansion of the MoO6 octahedra tunnel ruptures the Mo-O2 bonds, forming individual MoO6 octahedron zigzag chains that then share corners to generate octahedron layers in the ⟨100⟩α direction. The octahedron layers are bonded by van der Waals interactions in the ⟨010⟩α direction, crystalizing into the α-MoO3 structure.

Mechanical origin of shape memory performance for crosslinked epoxy networks

The mechanical principle of microstructural change governing the shape formation and restoration process of shape memory epoxy (SME) was analyzed on a subcontinuum scale. A series of processes to program and operate the microstructure of highly crosslinked networks across the phase transition temperature range was implemented in molecular dynamics simulations. This elucidated the mechanisms by which the chemical composition of resins and crosslinkers, the degree of orientation of each chain, and the topology of the entire network characterize the shape memory behavior of the system. The strategy for analyzing the mechanical behavior of molecules by classifying them into translation, rotation, and deformation based on the classical kinematic framework was particularly effective in clarifying the structure–property relationship. The results showed that, during the shape programming process, each molecular component of the SME was rearranged to different levels depending on its stiffness, forming local residual stresses. The principle leading to shape recovery as the subsequent thermal load removes residual stress and the resulting change in the mechanical anisotropy of the entire system were also successfully comprehended.

Formulation and phase change mechanism of Capric acid/Octadecanol binary composite phase change materials

Fatty acids and fatty alcohols have the advantages of high latent heat of phase change, good thermal stability, no corrosion, no supercooling and phase separation. They can be used as phase change energy storage materials for passive temperature control. However, their popularization and application are limited because of their high phase transition temperature and narrow phase transition range. This study develops a novel binary composite phase change materials (PCMs) of Capric acid (CA) and Octadecanol (OD) by a melt blending method. The theoretical calculation and hot melt-step cooling were carried out to generate an optimal molar ratio, followed by DSC thermal characterization. ATR-FTIR and XRD were performed to determine the phase transformation and chemical and structure changes. The results showed the binary CA-OD binary composite PCMs has a high latent heat of fusion, a melting temperature Tm = 26.48 °C and △H = 181.06 J/g at optimal mass ratio of 85.15:14.86 (CA:OD), which is higher than the theoretically predicted latent heat of phase transition, indicating a good synergistic effect beneficial to energy storage. Solid CA exists in the form of dimer and –OH in solid OD exists in form of association, and intermolecular hydrogen bonds weakens in liquid. There are hydrogen bonds in the CA-OD binary composite PCMs, and the molecular structure changes before and after the phase transformation were similar to that of a single component CA or OD. The crystal structures of the two compounds also change and the latent heat of phase transformation is improved. Finally, through TG and high and low temperature cycle test, CA-OD binary PCMs demonstrates good thermal stability and practicability in the field of building energy conservation.

Fire Retardance Methods and Materials for Phase Change Materials: Performance, Integration Methods, and Applications—A Literature Review

Thermal control methods based on phase change materials have a wide range of applications, from thermal management to latent heat storage for renewable energy systems, with intermittent availability. Organic PCMs have some advantages over inorganics; however, their major drawback is flammability. In critical applications, such as buildings, electric vehicles, and aerospace applications, flammability is an issue that must be addressed in order to comply with safety standards. This review paper covers current studies assessing the PCM response to fire or excessive temperature, methods for ensuring flame retardancy, and their impact on the PCMs key characteristics: phase transition temperature range, latent heat, heat transfer rate, and compatibility with other system materials. A special focus is set on the preparation methods and the effectiveness of the flame-retardance achievement method. Some research gaps and further research directions are identified and discussed.

Molecular dynamics method for numerical study of thermal performance of hexacosane PCM in a Cu-nanochannel

Due to the growth of energy consumption in world and limitation of fossil fuels, energy storage is of great importance. The n-Hexacosane (paraffin) is one of the most popular phase-change materials (PCMs) due to its high energy storage and low cost. Due to the number of carbon atoms, this structure reveals a wide phase transition temperature (Temp) range. In current research, thermal behavior (TB) of this PCM in a copper nanochannel investigated using molecular dynamics (MD) simulation. Also, initial Temp's effect on PCM's atomic behavior (AB) and TB investigated. Density (Dens), Temp, velocity (Vel) profiles, heat flux (HF), and thermal conductivity (TC) calculated to investigate studied structure's AB and TB. The obtained result reveals that TB of structure is improved by increasing initial Temp. Numerically, the Max-Vel and Temp from 0.0124 Å/fs and 329.41 K to 0.0139 Å/fs and 364.29 K by increasing initial Temp from 300 to 350 K, and TC and HF increased from 0.254 W/mK and 387.325 W/m2 to 0.275 W/mK and 411.023 W/m2, respectively. This increase is due to the increase in interatomic collisions with increasing Temp. By increasing number and intensity of collisions, amount of structure's heat transferred (HT) also rises; hence, TB of atomic samples improves.

Molecular dynamics simulation of phase transformation and wear behavior of Ni35Al30Co35 high temperature shape memory alloy

Ni–Al–Co alloys as one of the ferromagnetic high-temperature shape memory alloys (HTSMA) are attractive in aerospace and defense applications, due to their high phase transition temperature range (400–700K), high recoverable strain and good machinability. However, the underlying physics for the phase transformation behavior of β single-phase and β+γ two-phase Ni–Al–Co ternary alloys remain unclear. In this work, molecular dynamics simulation of phase transition, pseudoelasticity (PE) and wear behavior of Ni35Al30Co35 alloy were analyzed using the EAM potential. It shows that Ni35Al30Co35 alloy has a high martensite start temperature of 825K and an austenite start temperature of 631K, respectively. After five thermal cycles, martensite and austenite start and finish temperatures are stable around 500K and 700K. The initial structure of Ni35Al30Co35 alloy at 1000K is identified as BCC (β phase) and FCC (γ phase) structure, transforming to L10 structure through martensitic transformation. Furthermore, PE of Ni35Al30Co35 alloy exhibits about a 9.1% recoverable strain under <001> oriented uniaxial tension tests and about a 6.6% recoverable strain under <001> oriented uniaxial compression tests at a temperature of 1200K, showing the potential used in extreme environment. Moreover, spherical indenters with a radius of 15 Å were used to investigate the wear behavior of Ni35Al30Co35 alloy under different temperature. It was found that the PE effect affects the frictional behavior during nano-scratching. Combining the effect of high temperature softening and phase transition PE, the wear rate increases nearly by 5.3% when the temperature rises from 300K to 1000K. Furthermore, the friction force curve obtained is consistent with the friction force curve obtained by simulation at 300K.

Electrospun Core-Sheath Fibers with a Uniformly Aligned Polymer Network Liquid Crystal (PNLC).

Electrospun polymer-liquid crystal (PLC) fibers have potential applications such as wearable sensors and adaptive textiles because of their rapid response and high flexibility. However, existing PLC fibers only have a narrow responsive range and poor resistance to heat and chemicals. Herein, a new type of PLC fiber is prepared by using a coaxial electrospinning process. The core solution is 4'-pentyl-4-biphenylcarbonitrile (5CB), and the sheath solution is a mixture containing 13 wt % PVP and 10 wt % reactive mesogen (RM). After UV exposure of the fibers, 5CB in the core and RM diffusing from the core are cross-linked into an LC polymer. The fibers have a highly uniform morphology with an average diameter of 3.2 ± 0.5 μm, and mesogens inside the fibers align unidirectionally with the long axis of the fibers. The fibers show a broad phase-transition temperature range between 13.5 and 155.5 °C and have a response time of less than 10 s. The temperature range can also be controlled by adjusting components in the electrospun fibers and UV exposure time. The core-sheath fibers prepared in such a manner exhibit excellent heat and chemical resistance with reversible optical responses. Moreover, when the fibers are exposed to volatile organic compounds (VOCs) such as toluene, the fibers show a rapid optical response to toluene vapor within 25 s. This study demonstrates that the fibers are potentially useful for preparing flexible temperature and chemical sensors.

Unveiling the effect of molecular chain length on the thermal energy storage capacity and transition temperature of alkane-based phase change composites

Thermal energy storage systems based on phase-change materials (PCMs) have garnered significant attention, because they can overcome intermittency issues related to renewable energy sources. However, the energy storage capacity and phase-change temperature of phase-change composites largely depend on the PCM type and molecular weight, in addition to the supporting material type, and experimental studies on the thermal properties of PCMs with different molecular chain lengths are scarce. In this study, phase-change composites were prepared by the vacuum impregnation method using boron nitride (BN) as the support and n-alkanes of different chain lengths–dodecane (C12H26), and docosane (C22H46)–as the PCMs to study the effect of the alkane chain length on the thermal energy storage density and phase-change temperature. The BN@C22 composite exhibited greater latent heat storage capacity (125.11 kJ/kg) than the BN@C12 composite (70.84 kJ/kg), indicating the low confinement effect of the BN support on the long-chain n-alkane. In contrast, the BN functional groups and shorter-chain n-alkane had strong intermolecular interactions, which compromise the energy storage density for seepage resistance and shape stability. Both PCM composites exhibited good chemical compatibility between the two components, improved thermal durability, and insignificant leakage rate (up to 98.7% leakage resistance capability), while BN@C12 showed higher shape stability. The thermal performance of the as-prepared PCM composites, including their phase-transition temperature (range: −9.54 to + 43.53 °C), illustrates their potential for various thermal management applications, including indoor temperature-control systems. This study provides fundamental guidelines for tuning the working temperature range and improving the efficiency of thermal management systems.

Structural incorporation of europium into uranium oxides

Microparticulate reference materials with well-defined properties are needed by the International Atomic Energy Agency (IAEA) to consolidate a sustainable quality control system for analytical measurements for particle analysis in nuclear safeguards. In order to further develop analytical methods and quality control of the analytical results from particle analysis to detect even traces of dopants, such as fission products, the microparticulate reference materials must be refined according to the IAEA’s requirements. Due to yield limitations of the microparticles, a co-precipitation method was adapted to synthesize bulk-scale comparison materials doped with lanthanides to unravel the incorporation mechanism of those dopants into the uranium oxide structure in depth. Through TG-DSC studies, the temperature range of phase transitions from UO3 to U3O8 was identified and analyzed in more detail by additional systematic structural investigations of long- and short-range order phenomena with XRD and Raman, and IR, respectively.Graphical abstract

Decanoic acid-palmitic acid/SiO2@TiO2 phase change microcapsules based on RBF model with excellent photocatalysis performance and humidity control property.

The decanoic acid-palmitic acid composite phase change material compounds with SiO2 and TiO2 to prepare decanoic acid-palmitic acid/SiO2@TiO2 phase change microcapsules (D-P-SiO2@TiO2 PCM). The D-P-SiO2@TiO2 PCM could show efficient temperature regulation, remove pollutants through photocatalysis, and control air humidity. However, it is difficult to obtain the best experimental scheme directly using the traditional experimental setup due to the complicated photocatalytic-humidity performance. The radial basis function (RBF) model optimized the uniform experimental design parameters, and the D-P-SiO2@TiO2 PCM showed enhanced photocatalytic-humidity performance. The RBF-calculated preparation parameters were as follows: the molar ratio of decanoic acid-palmitic acid to tetraethyl silicate was 0.42, pH was 1.83, the molar ratio of deionized water to tetraethyl silicate was 98.15, while the molar rate of tetrabutyl titanate to tetraethyl silicate was 0.76. The degradation rate of gaseous formaldehyde by the RBF-optimized D-P-SiO2@TiO2 PCM was 69.57% after 6h, and the moisture content was between 0.0923 and 0.0940g·g-1 at 43.16-75.29% relative humidity (RH). The comparison between model optimization and the experiment sample prepared using the optimized parameters showed that the theoretical photocatalytic-humidity performance target value was 2.0502, and the tested target value was 2.0757. The error calculated from these two values was only 1.24%, and both were better than the best value of uniform experimental calculation. RBF mathematical model was proved to be an effective, convenient, and economic-saving method to simulate and predict D-P-SiO2@TiO2 PCM experimental design parameters. SEM and TEM analyses of the RBF-optimized D-P-SiO2@TiO2 PCM showed a uniform spherical structure, and the particle size analysis analyses was about 200nm. The DSC analysis showed the phase transition temperature range was between 16.97 and 28.94°C, within the comfort range of the human body. The UV-Vis investigations showed the absorption edge of the RBF-optimized D-P-SiO2@TiO2 PCM was 380nm, in line with the band gap structure of the TiO2 anatase phase. The thermogravimetric investigations showed that this composite was stable at normal temperature and pressure. After a 100 times hot-cold cycle, the quality of the RBF-optimized D-P-SiO2@TiO2 PCM maintained its stability, as the photocatalytic-humidity performance was almost the same. The N2-adsorption analysis showed it had a high specific surface area and irregular pore structures, which could help it regulate air humidity. Considering these results, the D-P-SiO2@TiO2 PCM, a new ecological functional material, would be used in the construction industry to improve the architectural ecological environment.