CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Yuantao Xie,Lirong Yang,Chunmei Wang,Xiaoxin Feng,Zezheng Tang,Zhigang Liu
The polyvinyl alcohol (PVA) reinforced macro-defect-free α-hemihydrate gypsum composite (PMC) was prepared by compression molding technique. The mechanical strength from the age of 3 d to 120 d and water resistance of PMC were tested, and the phase composition, microstructure, pore structure of PMC was characterized by SEM, XRD, TGA and MIP. The results show that the compressive and flexural strength of PMC with 1 % PVA addition cured for 3 d reach 80.9 MPa and 23.2 MPa, respectively. A compacted gypsum crystal structure is obtained by using the compression molding technique and the PVA film in PMC matrix can absorb fracture energy, which makes PMC have high mechanical strength. Due to the low water to gypsum ratio, the main crystalline phases detected in PMC consist of CaSO 4 ·2H 2 O and CaSO 4 ·0.5H 2 O. The TG curves show that the hydration degree of PMC may be further limited by the excessive incorporation of PVA, which is not conductive to the strength development. The softening coefficient of PMC with 2 % PVA addition gets to 0.81. The diffusion rate of water in the matrix can be reduced because of the compact structure of PMC and the hindering effect of PVA film on water diffusion, which improves the water resistance of PMC.
研究领域:
建筑材料学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 7
·1510
·
IF 3.1
Yuan Chen,Zerui Mi,Jiatong Yang,Xuan Zheng,Huihu Wang,Marie-Christine Record,Pascal Boulet,Juan Wang,Jan-Michael Albina,Yiwan Huang
This study combined inorganic α-hemihydrate gypsum (α-HHG) with organic polyacrylamide (PAM) hydrogel to create a novelα-HHG/PAM composite material. Through this facile composite strategy, this fabricated material exhibited a significantly longer initial setting time and higher mechanical strength compared toα-HHG. The effects of the addition amount and the concentration of PAM precursor solution on the flowability of theα-HHG/PAM composite material slurry, initial setting time, and mechanical properties of the hardened specimens were investigated. The structural characteristics of the composite material were examined using XRD, FE-SEM, and TGA. The results showed that the initial setting time of theα-HHG/PAM composite material was 25.7 min, which is an extension of 127.43% compared to that ofα-HHG. The flexural strength and compressive strength of the oven-dried specimens were 23.4 MPa and 58.6 MPa, respectively, representing increases of 34.73% and 84.86% over values forα-HHG. The XRD, FE-SEM, and TGA results all indicated that the hydration ofα-HHG in the composite material was incomplete. The incompleteness is caused by the competition between the hydration process of inorganicα-HHG and the gelation process of the acrylamide molecules for water, which hinders someα-HHG from entirely reacting with water. The enhanced mechanical strength of theα-HHG/PAM composite material results from the tight interweaving and integrating of organic and inorganic networks. This study provides a concise and efficient approach to the modification research of hemihydrate gypsum.
研究领域:
建筑材料学
·
材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Xiaosong Ma,Linzhen Tan,Yuanjing Lu,Wu Yao,Yongqi Wei
A large number of waste gypsum was reused of low-value or landfilled which caused serious waste of resources. In this study, a high value-added recycling scheme for waste building gypsum to synthesize a 3D printable material with high-precision was designed. The α-hemihydrate gypsum (α-HH) was synthesized from waste plasterboard by the salt solution hydrothermal method. A synergistic optimization strategy was proposed involving the effect of sodium succinate and pH on the morphology and mechanical strength of α-HH. The properties of recycled α-HH were modified to meet the requirements of 3D printing , including fluidity, setting time and green strength. When the modifier dosage is 0.05 wt% and the pH is 5, the best morphology of α-HH crystals with an average aspect ratio of 1.07 (length of 10 μm) are synthesized. The converted product has close interlocking and intergrowth after hydration, which exhibits excellent mechanical strength (25.5 MPa). The 3D printing materials prepared by the composite modification of recycled α gypsum powder has proven to achieve good printable. The print errors smaller than 4% for pore objects larger than 4.0 mm, and satisfactory results are shown in terms of the strength and resolution of printing high detail cavity structures. This work provides a high value-added upcycling scheme for waste building gypsum that has great potentiality for future industrial application.
研究领域:
建筑材料学
·
资源与环境工程
·
材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Guangli Ye,Kun Yu,Mengyuan Niu,Qian Wang,Menghan Yu,Xiongbo Dong,Huaming Yang
Minerals have been growing as an emerging ‘hot’ topic in separating water-in-oil emulsions. Whether the intrinsic structure of minerals could precisely regulate water–mineral interactions for enhancing emulsions separation efficiency is still ambiguous. Here, taking half-hydrated gypsum as a case, this study reveals the crystal facet-dependent potential mechanism of minerals in water-in-oil emulsions separation. We show that the (2 0 4) facet of half-hydrated gypsum is more susceptible to water-induced degradation and hydration reaction. With combined experimental and theoretical studies, the facet-dependent mechanism for oil–water separation are revealed; the (2 0 4) facet that exhibited weak internal hydrogen bond and strong binding energy with water accelerated the dissolution and recrystallization of half-hydrated gypsum, thus enhancing oil–water separation efficiency. Through engineering, half-hydrated gypsum with a higher surface fraction of the (2 0 4) facet achieved much higher separation efficiency (99.9%), surpassing those of minerals in disclosed literature. This investigation not only contributes significantly to the comprehension of interactions at the minerals-water interface but also illuminates novel perspectives and avenues for the utilization of facet engineering in advancing research on mineral surface properties.
研究领域:
材料科学
·
环境工程
·
化学工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 9
·2002
·
IF 4.6
Yuan Chen,Li Chen,Hao Li,Bin Zhang,Marie-Christine Record,Pascal Boulet,Juan Wang,Jan-Michael Albina,Yi Yang,Weiliang Ma
In this study, a novel calcium phosphate/polyacrylamide copolymer/ α -type hemihydrate gypsum (CPO/PAM/ α -HHG) composite material was prepared by polymerising a stable inorganic CPO precursor, end-capped with triethylamine (TEA), with an organic polyacrylamide (PAM) hydrogel to form a CPO/PAM precursor solution. Subsequently, this precursor solution was mixed with inorganic α -hemihydrate gypsum. The effects of CPO/PAM precursor addition and CPO addition on the slurry flowability, initial setting time, and mechanical properties of hardened specimens of the CPO/PAM/ α -HHG composite were investigated. The structural characteristics of the composites were analysed by XRD, FE-SEM, and TGA. The results show that the initial setting time of the CPO/PAM/ α -HHG composites was 26.7 min, which was 140.5% longer than that of the pure water α -HHG system and 3.9% longer than that of the PAM/ α -HHG system; additionally, the oven-dried specimens had a flexural strength of 27.59 MPa and a compressive strength of 68.48 MPa, which were 77.2% and 102.0% higher than those of the pure water α -HHG system and 38.8% and 14.1% higher than those of the PAM/ α -HHG system, respectively. The wet compressive strength of the CPO/PAM/ α -HHG composites was improved by 11.8% compared to that of the PAM/ α -HHG system. A structural analysis showed that CPO promoted the gelation process of PAM and allowed the hydration reaction process of α -HHG to be fully carried out by slowing down the gelation process of the organic network, which led to the full development of both organic and inorganic networks, ultimately forming an interspersed inorganic/organic dual-network structure, which enhanced the comprehensive mechanical properties of the composites. This study provides a new idea for the modification of α -type hemihydrate gypsum and a new method for the preparation of high-utilisation and high-performance gypsum-based composites.
研究领域:
建筑材料学
·
复合材料科学
·
无机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）