为什么染发剂要配合双氧水（过氧化氢）？
Why do hair dyes need hydrogen peroxide?
永久性染发靠小分子无色前体渗入头发，再用双氧水氧化聚合成大分子有色染料并锁在发丝内。双氧水还把头发天然黑色素漂淡，好让目标色显出来。浓度越高漂色越强，但也更伤发质。
Permanent dye uses small colorless precursors that penetrate the hair, then hydrogen peroxide oxidizes and polymerizes them into large colored molecules trapped inside the shaft. Peroxide also lightens natural melanin so the target color shows. Higher strength bleaches more but damages hair more.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#染发 #双氧水 #氧化
为什么防晒霜分物理防晒和化学防晒？
Why are sunscreens split into physical and chemical types?
物理防晒剂（二氧化钛、氧化锌）像小镜子反射散射紫外线；化学防晒剂（如奥克立林）吸收紫外线并转化为热量释放。物理类温和不易致敏但偏白，化学类轻薄但个别成分可能刺激。常二者复配兼顾效果与肤感。
Physical filters like titanium dioxide and zinc oxide reflect and scatter UV like tiny mirrors, while chemical filters like octocrylene absorb UV and release it as heat. Physical types are gentle but leave a white cast; chemical types feel light but some can irritate. They are often combined for effect and feel.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#防晒 #物理 #化学
为什么维生素C（抗坏血酸）能提亮肤色、美白？
Why does vitamin C (ascorbic acid) brighten and whiten skin?
维生素C能抑制酪氨酸酶活性，减少黑色素生成，还能把已形成的黑色素还原、淡化色斑。它也是抗氧化剂，能对抗紫外线和污染造成的自由基损伤。但本身不稳定易氧化，常做成衍生物或避光包装。
Vitamin C inhibits tyrosinase, cutting melanin production, and also reduces existing melanin to fade spots. As an antioxidant it counters free-radical damage from UV and pollution. But it is unstable and oxidizes easily, so it is often used as a derivative or in opaque packaging.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#维生素C #美白 #抗氧化
为什么护肤品要加防腐剂？
Why do skin products contain preservatives?
护肤品的水和营养成分是微生物的温床，不加防腐剂容易长菌变质、引发皮肤感染。防腐剂抑制细菌真菌繁殖，保证产品在保质期内安全。合理用量下对大多数人安全，敏感肌可选无防腐或精简配方。
The water and nutrients in skincare are a haven for microbes, so without preservatives products spoil and can infect skin. Preservatives curb bacteria and fungi to keep them safe through shelf life. At proper levels they are safe for most; sensitive skin can choose preservative-free or minimal formulas.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#防腐剂 #微生物 #保质
为什么口红沾杯却不溶于水？
Why does lipstick resist water but stain cups?
口红主体是蜡、油和色粉，蜡和油都是疏水的，水难以润湿溶解，所以不溶于水。它靠油脂附着在嘴唇上，喝水沾杯是表面油膜被带走。卸妆需用油性或含表面活性剂的卸妆产品。
Lipstick is mostly wax, oil, and pigment; wax and oil are hydrophobic and water cannot wet or dissolve them, so it is water-resistant. It sticks via the oil film, which transfers to a cup when drinking. Removing it needs an oily or surfactant-based makeup remover.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Rosen & Kunjappu《表面活性剂与界面现象》（第4版），第1章
Rosen & Kunjappu, "Surfactants and Interfacial Phenomena" (4th ed.), Ch.1
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-1-118-22902-6 (2012, Wiley)
#口红 #疏水 #油溶
为什么氨基酸洗面奶更温和？
Why are amino-acid face cleansers gentler?
氨基酸表面活性剂以氨基酸为亲水头，结构与皮肤天然成分接近，在弱酸性下清洁力适中、脱脂少，对皮脂膜刺激小。相比强硫酸盐表活（如SLES），它洗后不易紧绷。但成本较高，常与其他表活复配。
Amino-acid surfactants use an amino acid as the hydrophilic head, close to the skin's own components, and clean moderately at skin's weak acidity with little degreasing, so they irritate the barrier less. Versus strong sulfate surfactants like SLES, they leave skin less tight. They cost more and are often blended.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
Rosen & Kunjappu《表面活性剂与界面现象》（第4版），第1章
Rosen & Kunjappu, "Surfactants and Interfacial Phenomena" (4th ed.), Ch.1
独立核验依据 · Independent verification: 核验依据 1 ISBN 978-1-118-22902-6 (2012, Wiley)
#氨基酸 #表活 #温和
视黄醇（维 A 醇）为什么能抗老？
Why does retinol (vitamin A alcohol) anti-age skin?
它在皮肤中转成维 A 酸，调控基因促进胶原并加速更新，但易光解刺激，宜夜间使用。
It converts to retinoic acid in skin, regulating genes to boost collagen and turnover; but it is light-sensitive and irritating, so best used at night.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#视黄醇 #抗老 #维A
止汗剂为什么能让人少出汗？
Why do antiperspirants reduce sweating?
其中的铝盐暂时膨胀并堵住汗腺开口，汗液排不出去，从而保持干爽（不同于只遮味的香体剂）。
Aluminum salts temporarily swell and plug sweat-duct openings, blocking sweat—unlike deodorants that only mask odor.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#止汗 #铝盐 #汗腺
为什么爽身粉能让皮肤干爽、减少摩擦？
Why does body powder keep skin dry and reduce friction?
爽身粉常用滑石粉或玉米淀粉，颗粒细小能吸收多余汗液和油脂，保持皮肤表面干爽。它还能减少皮肤褶皱间的摩擦，预防痱子和红屁股。注意传统滑石粉需选正规无石棉产品，婴儿可用玉米淀粉更安全。
Talc or corn starch in body powder has fine particles that absorb excess sweat and oil, keeping the surface dry. It also cuts friction between skin folds, preventing heat rash and chafing. Choose certified asbestos-free talc, or safer corn starch for babies.
难度 入门 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#爽身粉 #吸湿 #滑石粉
为什么香水里要加酒精？
Why does perfume contain alcohol?
酒精是很好的溶剂，能把香精均匀溶解并帮助它快速、均匀地挥发扩散到空气中。它蒸发时还带走热量，带来清凉感。无酒精香水多用油作基底，留香和扩散方式不同。
Alcohol is an excellent solvent that dissolves the fragrance evenly and helps it diffuse quickly and uniformly into the air. As it evaporates it also carries heat, giving a cooling feel. Alcohol-free perfumes use oils instead, changing how scent develops and lasts.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Brown, LeMay 等,《Chemistry: The Central Science》第14版,Pearson,2017
T. L. Brown et al., Chemistry: The Central Science, 14th ed., Pearson, 2017
#香水 #酒精 #溶剂
为什么敷面膜后皮肤显得水润？
Why does skin look hydrated after a sheet mask?
面膜用封闭性敷料把水和保湿剂（如甘油、透明质酸）压在皮肤表面，暂时提高角质层含水量，所以看起来饱满透亮。它主要起即时补水和舒缓作用，效果不持久。敷后及时涂乳液锁水更关键。
The mask's occlusive sheet presses water and humectants like glycerin or hyaluronic acid onto the skin, temporarily raising the moisture in the stratum corneum so it looks plump and bright. It is mainly an instant boost and soothing, not lasting. Sealing with a lotion right after matters more.
难度 入门 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#面膜 #保湿 #角质层
为什么凡士林能保湿、保护皮肤？
Why does petroleum jelly moisturize and protect skin?
凡士林是惰性的矿物油膏，涂抹后在皮肤表面形成一层疏水薄膜，阻止水分蒸发（封闭保湿）。它不被皮肤吸收、不致敏，适合干裂部位和隔离刺激。但它不补水，需先涂水性或精华再封层。
Petroleum jelly is an inert mineral ointment that forms a hydrophobic film on the skin, blocking water loss—occlusive moisturizing. It is not absorbed and rarely sensitizes, good for cracked areas and shielding irritants. It adds no water, so apply it over a watery serum to seal in moisture.
难度 入门 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Royal Society of Chemistry（护肤与化妆品化学）
Royal Society of Chemistry (skincare and cosmetic chemistry)
#凡士林 #封闭保湿 #疏水